[Federal Register Volume 90, Number 146 (Friday, August 1, 2025)]
[Proposed Rules]
[Pages 36288-36365]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-14572]
[[Page 36287]]
Vol. 90
Friday,
No. 146
August 1, 2025
Part II
Environmental Protection Agency
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40 CFR Parts 85, 86, 600, et al.
Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle
Standards; Proposed Rule
Federal Register / Vol. 90 , No. 146 / Friday, August 1, 2025 /
Proposed Rules
[[Page 36288]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 85, 86, 600, 1036, 1037, and 1039
[EPA-HQ-OAR-2025-0194; FRL-12715-01-OAR]
RIN 2060-AW71
Reconsideration of 2009 Endangerment Finding and Greenhouse Gas
Vehicle Standards
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: In this action, the U.S. Environmental Protection Agency (EPA)
is proposing to repeal all greenhouse gas (GHG) emission standards for
light-duty, medium-duty, and heavy-duty vehicles and engines to
effectuate the best reading of Clean Air Act (CAA) section 202(a). We
propose that CAA section 202(a) does not authorize the EPA to prescribe
emission standards to address global climate change concerns and, on
that basis, propose to rescind the Administrator's prior findings in
2009 that GHG emissions from new motor vehicles and engines contribute
to air pollution which may endanger public health or welfare. We
further propose, in the alternative, to rescind the Administrator's
prior findings in 2009 because the EPA unreasonably analyzed the
scientific record and because developments cast significant doubt on
the reliability of the findings. Lastly, we propose to repeal all GHG
emission standards on the alternative bases that no requisite
technology for vehicle and engine emission control can address the
global climate change concerns identified in the findings without
risking greater harms to public health and welfare.
DATES:
Comments. Comments must be received on or before September 15,
2025. Comments on the information collection provisions submitted to
the Office of Management and Budget (OMB) under the Paperwork Reduction
Act (PRA) are best assured of consideration by OMB if OMB receives a
copy of your comments on or before September 2, 2025.
Public Hearing. The EPA will announce information regarding the
public hearing for this proposal in a supplemental Federal Register
document. Please refer to the SUPPLEMENTARY INFORMATION section for
additional information on the public hearing.
ADDRESSES: Comments. You may send comments, identified by Docket ID No.
EPA-HQ-OAR-2025-0194, by any of the following methods:
Federal eRulemaking Portal: https://www.regulations.gov/
(our preferred method). Follow the online instructions for submitting
comments.
Email: [email protected]. Include Docket ID No. EPA-
HQ-OAR-2025-0194 in the subject line of the message.
Mail: U.S. Environmental Protection Agency, EPA Docket
Center, OAR Docket, Mail Code 28221T, 1200 Pennsylvania Avenue NW,
Washington, DC 20460.
Hand Delivery or Courier: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m.,
Monday-Friday (except Federal Holidays).
Instructions. All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to https://www.regulations.gov/, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.
FOR FURTHER INFORMATION CONTACT: Alan Stout, Assessment and Standards
Division, Office of Transportation and Air Quality, Environmental
Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105;
telephone number: (734) 214-4805; email address: [email protected].
SUPPLEMENTARY INFORMATION:
A. Public Participation
Written Comments. Submit your comments, identified by Docket ID No.
EPA-HQ-OAR-2025-0194, at https://www.regulations.gov (our preferred
method), or the other methods identified in the ADDRESSES section. Once
submitted, comments cannot be edited or removed from the docket. The
EPA may publish any comment received to its public docket. Do not
submit to the EPA's docket at https://www.regulations.gov any
information you consider to be Confidential Business Information (CBI),
Proprietary Business Information (PBI), or other information whose
disclosure is restricted by statute. If you choose to submit CBI or PBI
as a comment to the EPA's docket, please send those materials to the
person listed in the FOR FURTHER INFORMATION CONTACT section.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered an official comment
and should include discussion of all points you wish to make. The EPA
will generally not consider comments or comment contents located
outside of the primary submission (i.e., on the web, cloud, or other
file sharing system). Please visit https://www.epa.gov/dockets/commenting-epa-dockets for additional submission methods; the full EPA
public comment policy; information about CBI, PBI, or multimedia
submissions; and general guidance on making effective comments.
To facilitate comment on the portions of the rule on which the EPA
is specifically soliciting comment, the EPA has indexed each comment
solicitation with a unique identifier (e.g., ``C-1'', ``C-2'') in
section VII of this preamble to provide a consistent framework for
effective and efficient provision of comments. Accordingly, we ask that
commenters include the corresponding identifier when providing comments
relevant to that comment solicitation. We ask that commenters include
the identifier either in a heading or within the text of each comment,
to make clear which comment solicitation is being addressed. We note
that we are not limiting comment to these identified areas.
Participation in Virtual Public Hearing. The EPA will announce
information regarding the public hearing for this proposal in a
supplemental document in the Federal Register. The hearing notice,
registration information, and any updates to the hearing schedule will
also be available at https://www.epa.gov/regulations-emissions-vehicles-and-engines/proposed-rule-reconsideration-2009-endangerment-finding. Please refer to this website for any updates regarding the
hearings. The EPA does not intend to publish additional documents in
the Federal Register announcing updates to the hearing schedule.
Docket. All documents in the docket are listed on the
www.regulations.gov website. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the internet and will be
publicly available only in hard copy form through the EPA Docket Center
at the location listed in the ADDRESSES section of this document.
[[Page 36289]]
B. Action Applicability
This action relates to companies that manufacture, sell, or import
into the United States light-, medium-, or heavy-duty motor vehicles
and engines. Potentially affected categories and entities include the
following:
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NAICS code \a\ NAICS title
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336110........................ Automobile and Light-duty Motor Vehicle
Manufacturing.
336120........................ Heavy Duty Truck Manufacturing.
336211........................ Motor Vehicle Body Manufacturing.
336213........................ Motor Home Manufacturing.
336310........................ Motor Vehicle Gasoline Engine and Engine
Parts Manufacturing.
336390........................ Other Motor Vehicle Parts Manufacturing.
333618........................ Other Engine Equipment Manufacturing.
423110........................ Automobile and Other Motor Vehicle
Merchant Wholesalers.
811198........................ All Other Automotive Repair and
Maintenance.
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\a\ NAICS Association. NAICS & SIC Identification Tools. Available
online: https://www.naics.com/search.
This table is not intended to be exhaustive but rather provides a
guide for readers regarding entities potentially affected by this
action. This table lists the types of entities that the EPA is
presently aware could potentially be affected by this action. Other
types of entities not listed in the table could also be affected. To
determine whether your entity is regulated by this action, you should
carefully examine the applicability criteria found in Code of Federal
Regulations (CFR) title 40, parts 85, 86, 600, 1036, and 1037. If you
have questions regarding the applicability of this action to a
particular entity, consult the person listed in the FOR FURTHER
INFORMATION CONTACT section.
Table of Contents
I. Executive Summary
A. Introduction
B. Need for Regulatory Action
C. Summary of the Major Provisions in This Proposed Action
II. Background
A. The EPA's Historical Approach to CAA Section 202(a)
B. Petitions for Rulemaking and Massachusetts v. EPA
C. The 2009 Endangerment Finding
D. Implementation of the 2009 Endangerment Finding
E. Reconsideration of the 2009 Endangerment Finding
III. Legal Framework for Proposed Action
A. Proposed Rescission of Endangerment Finding
B. Proposed Amendments to New Motor Vehicle and Engine
Regulations
IV. Proposed Rescission of the Endangerment Finding
A. Primary Rationale for Proposed Rescission
1. Best Reading of CAA Section 202(a)
2. Lack of Clear Congressional Authorization
B. Alternative Rationale for Proposed Rescission
1. Climate Science Discussion
2. Proposed Conclusions
V. Separate Bases for Proposed Repeal of GHG Emission Standards
A. There Is No Requisite Technology for Light- and Medium-Duty
Vehicles That Meaningfully Addresses the Identified Dangers of the
Six ``Well-Mixed'' GHGs
B. There Is No Requisite Technology for Heavy-Duty Vehicles That
Addresses the Identified Dangers of the Six ``Well-Mixed'' GHGs
C. Eliminating GHG Emissions From All Motor Vehicles Would Be
Futile
D. More Expensive New Vehicles Prevent Americans From Purchasing
New Vehicles That Are More Efficient, Safer, and Emit Fewer GHGs
VI. Proposed Repeal of GHG Emission Standards
A. Scope and Impacts of Proposed Repeal
B. Light- and Medium-Duty Vehicle GHG Program
1. Background on the Light- and Medium-Duty Vehicle GHG Program
2. Proposed Changes to the Light- and Medium-Duty Vehicle GHG
Regulations
C. Heavy-Duty Engine and Vehicle GHG Program
1. Background on the Heavy-Duty Engine and Vehicle GHG Program
2. Proposed Changes to the Heavy-Duty Engine and Vehicle GHG
Regulations
VII. Requests for Comment
VIII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 14094: Modernizing Regulatory Review
B. Executive Order 14192: Unleashing Prosperity Through
Deregulation
C. Paperwork Reduction Act (PRA)
1. Light- and Medium-Duty Vehicle--2024 Final Rule
2. Heavy-Duty Vehicle GHG Phase 3--2024 Final Rule
3. Nonroad Compression-Ignition Engines and On-Highway Heavy
Duty Engines, Supporting Statement for Information Collection
Request (March 2023 Revision)
D. Regulatory Flexibility Act (RFA)
E. Unfunded Mandates Reform Act (UMRA)
F. Executive Order 13132: Federalism
G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
H. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
J. National Technology Transfer and Advancement Act (NTTAA) and
1 CFR Part 51
I. Executive Summary
A. Introduction
In this action, the EPA proposes to rescind all greenhouse gas
(GHG) emission standards for light-duty, medium-duty, and heavy-duty
vehicles and engines under CAA section 202(a). Upon review of the
underlying actions and intervening legal and scientific developments,
including recent decisions by the U.S. Supreme Court and the scientific
information summarized in this preamble, the EPA no longer believes
that we have the statutory authority and record basis required to
maintain this novel and transformative regulatory program. We seek
comment on all aspects of this proposal, including on the legal and
scientific developments that are being subject to public comment for
the first time in this rulemaking.
In 2009, the EPA took the unprecedented step of asserting authority
to regulate GHG emissions in a standalone action titled ``Endangerment
and Cause or Contribute Finding for Greenhouse Gases Under Section
202(a) of the Clean Air Act,'' 74 FR 66496 (Dec. 15, 2009)
(Endangerment Finding). In that action, we interpreted CAA section
202(a) for the first time to authorize regulation of domestic emissions
from new motor vehicles and engines based on global climate change
concerns rather than air pollution that endangers public health or
welfare through local or regional exposure. 74 FR 66526-27. We also
asserted that because the statute is ``silent on [the] issue,'' CAA
section 202(a) grants ``procedural discretion'' to issue standalone
findings that trigger a duty to regulate without considering the
standards that must issue in response.
[[Page 36290]]
74 FR 66501-02. The Administrator exercised this newfound discretion to
make separate findings that elevated global concentrations in the upper
atmosphere of six ``well-mixed GHGs''--carbon dioxide (CO2),
methane, nitrous oxide (N2O), hydrofluorocarbons (HFCs),
perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)--
constitute ``air pollution'' that may reasonably be anticipated to
endanger public health and welfare, 74 FR 66516-36, and that GHG
emissions from all potential classes of motor vehicles and engines
contribute to such elevated global concentrations of GHGs in the upper
atmosphere and therefore to air pollution that endangers public health
and welfare, 74 FR 66536-45.
With respect to endangerment, the Administrator found that global
concentrations of GHGs from all foreign and domestic sources
``constitute the largest anthropogenic driver of climate change'' and
attributed climate change impacts to global GHG concentrations. 74 FR
66517. Next, the Administrator summarized literature reviews finding
that climate change ``can increase the risk of morbidity and
mortality'' indirectly through increased global temperature, air
quality effects, and changes in extreme weather events and can impact
welfare indirectly through net impacts on food production, forestry,
water resources, sea level rise, energy infrastructure, and ecosystems.
74 FR 66522-35. On that basis, the Administrator found that global
concentrations of GHGs constitute ``air pollution'' that endangers
public health and welfare. 74 FR 66516. For purposes of this preamble,
we use the phrase global climate change concerns to refer to the risks
the Administrator associated with climate change in 2009.
With respect to causation or contribution, the Administrator used
emissions data for existing motor vehicles and engines to project that
all potential classes of new motor vehicles and engines would emit four
GHGs--CO2, methane, N2O, and HFCs--that would
collectively amount to 4.3 percent of global GHG emissions. 74 FR
66543. The Administrator acknowledged that more would usually be
required to support contribution ``when addressing a more typical local
or regional air pollution problem.'' 74 FR 66539. Nevertheless,
asserting discretion to interpret the ambiguous term ``contribute,''
the Administrator found that the ``unique'' nature of global climate
change meant that ``contributors must do their part even if their
contributions to the global climate change problem, measured in terms
of percentage, are smaller than typically encountered when tackling
solely regional or local environmental issues.'' 74 FR 66542-43.
The EPA subsequently relied on the Endangerment Finding to impose
increasingly stringent GHG emission standards for new motor vehicles
and engines and to attempt, largely without success, to extend its GHG
initiative into additional CAA programs. In Utility Air Regulatory
Group v. EPA, 573 U.S. 302 (2014) (UARG), the Supreme Court rejected
our attempt to extend GHG emission standards to stationary sources
subject to Title I and Title V requirements, including after we
admitted that applying the statutory scheme as written to GHG emissions
from most covered stationary sources would be unworkable. And in West
Virginia v. EPA, 597 U.S. 697 (2022), the Court vacated our attempt to
shift the power grid away from using fossil fuels through GHG standards
for existing power plants under CAA section 111(d). The Court held in
both cases that the agency actions at issue implicated the major
questions doctrine, and that Congress must clearly authorize agencies
to take actions that decide major questions of policy. Nevertheless,
the EPA continued to retain and expand GHG emission standards for new
motor vehicles and engines that impose billions of dollars in
compliance costs on American businesses and consumers. Meanwhile,
global GHG concentrations in the upper atmosphere have continued to
rise, driven primarily by increased emissions from foreign sources,\1\
all without producing the degree of adverse impacts to public health
and welfare in the United States that the EPA anticipated in the 2009
Endangerment Finding.
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\1\ Crippa, M. et al. (2023). GHG emissions of all world
countries. Publications Office of the European Union: https://doi.org/10.2760/953322.
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The EPA now proposes to rescind the Endangerment Finding and all
resulting GHG emission standards for new motor vehicles and engines,
including the light-duty, medium-duty, and heavy-duty vehicle and
engine standards for model years (MY) 2012 to 2027 and beyond. The
remainder of this section describes the need for regulatory action and
the scope of the proposed action, including rescission of the
Endangerment Finding, repeal of related GHG emission standards, and
minor conforming adjustments to unrelated emission standards for new
motor vehicles and engines that we are not proposing to alter as part
of this rulemaking.
Section II of this preamble sets out relevant background, including
the events leading up to the Endangerment Finding, the approach taken
in the Endangerment Finding to analyzing the scientific record, and the
regulations issued since 2009 in reliance on the Endangerment Finding.
We also summarize the premises, assumptions, and conclusions in the
Endangerment Finding and the scientific information, including
empirical data, peer-reviewed studies, and real-world developments
since 2009 that led the Administrator to develop concerns sufficient to
initiate reconsideration of the ongoing validity and reliability of the
Endangerment Finding.
Section III of this preamble describes our legal authority to
rescind the Endangerment Finding and repeal the resulting GHG standards
issued under CAA section 202(a). Because this proposed action would not
impact fuel economy standards and emission standards for criteria
pollutants and hazardous air pollutants regulated under the CAA, we
explain the relationship between these regulations to set the outer
bounds of amendments at issue in this rulemaking.
Section IV.A of this preamble describes our proposal to rescind
these prior actions because the Endangerment Finding exceeded our
statutory authority under CAA section 202(a). As explained further
below, we propose that the term ``air pollution'' as used in CAA
section 202(a) is best read in context as referring to local or
regional exposure to dangerous air pollution, consistent with our
longstanding practice before 2009. We further propose that CAA section
202(a) does not grant the Administrator ``procedural discretion'' to
issue standalone findings that trigger a duty to regulate, or,
conversely, to prescribe standards, without making the requisite
findings for the particular air pollutant emissions and class or
classes of new motor vehicles or engines at issue. We also propose that
CAA section 202(a) does not authorize the Administrator to make
separate findings for endangerment and causation or contribution.
Rather, we propose that CAA section 202(a) requires the Administrator
to find that the relevant air pollutant emissions from the class or
classes of new motor vehicles or engines at issue cause, or contribute
to, air pollution which endangers public health or welfare, without
relying on emissions from stationary or other sources regulated by
distinct CAA provisions. As the Supreme Court made clear in Loper
Bright Enterprises v. Raimondo, 603 U.S. 369 (2024), we can no longer
rely on statutory silence or ambiguity to expand our regulatory power.
And
[[Page 36291]]
because the Nation's response to global climate change concerns is an
issue of significant importance that Congress did not clearly address
in CAA section 202(a), we propose that the major questions doctrine
further reinforces and provides an additional basis for our proposed
interpretations and actions. The Agency did not have the benefit of the
Court's decisions in Loper Bright and West Virginia, among other
applicable precedents, when issuing the Endangerment Finding in 2009.
Finally, we explain that the EPA reached contrary conclusions in the
Endangerment Finding by misconstruing the Supreme Court's decision in
Massachusetts v. EPA, 549 U.S. 497 (2007), which vacated our denial of
a petition for rulemaking on distinct grounds. Read on its own terms,
Massachusetts did not require the Agency to find that GHGs are subject
to regulation under CAA section 202(a) and does not support our
implementation of the statute since 2009.
Section IV.B of this preamble describes our alternative proposal to
rescind these prior actions even if CAA section 202(a) authorizes the
EPA to address GHG emissions based on global climate change concerns by
concluding that the Administrator exercised that authority unreasonably
in the Endangerment Finding. Specifically, we propose that the EPA
misapplied the statutory standard for regulation to the scientific
record by severing the analysis into separate parts without considering
whether all parts of the analysis, taken as a whole, supported the
findings and regulatory determinations required by the statute. We
further propose that empirical data, peer-reviewed studies, and real-
world developments since 2009 have cast significant doubt on many of
the critical premises, assumptions, and conclusions in the Endangerment
Finding such that it would be unreasonable to retain the decision and
the resulting regulatory framework. In proposing this alternative, we
note that the Supreme Court has continued to emphasize that agencies
have significant discretion when making complex judgments within the
bounds of an authorizing statute.\2\ We propose that the Administrator
may now exercise the discretion expressly delegated to him by Congress
in the text of CAA section 202(a) by rescinding the Endangerment
Finding.
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\2\ Seven Cnty. Infrastructure Coal. v. Eagle Cnty., 145 S. Ct.
1497, 1511-15 (2025); FDA v. Wages & White Lion Invs., L.L.C., 145
S. Ct. 898, 917 (2025); Baltimore Gas & Elec. Co. v. NRDC, Inc., 462
U.S. 87, 103 (1983); see also Huntsman Petrochemical LLC v. EPA, 114
F.4th 727, 735 (D.C. Cir. 2024) (``In the case of EPA's evaluation
of scientific data within its area of expertise, [courts] accord an
extreme degree of deference.'' (quotation marks omitted)).
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Section V of this preamble proposes additional bases for repealing
the EPA's GHG emission standards for new motor vehicles and engines
under CAA section 202(a) even if the Endangerment Finding were to
remain in place. We propose that there is no ``requisite technology''
responsive to the global climate change concerns identified in the
Endangerment Finding given evidence that reducing GHG emissions from
new motor vehicles and engines to zero would not have a scientifically
measurable impact on global GHG concentrations and climate trends. We
also propose that, on balance, and contrary to the core objectives of
CAA section 202(a), GHG emission standards harm public health and
welfare by increasing prices, decreasing consumer choice, and slowing
the replacement of older vehicles that are less safe and emit a greater
volume and variety of air pollutants than new motor vehicles and
engines.
Section VI of this preamble details the scope of the proposed
repeal, including its relationship to distinct regulatory programs and
federal preemption, the revisions to 40 CFR parts 85, 86, 600, 1036,
1037, and 1039 required to effectuate repeal of all GHG emission
standards, and conforming adjustments to regulatory provisions that we
are not proposing to reopen or substantively revise. Specifically, in
this NPRM we are not proposing to change at this time elements of the
regulations that are necessary for programs unrelated to the
Endangerment Finding, including emission standards for criteria
pollutants and air hazards and the EPA's statutory role in vehicle
standards administered by the National Highway Traffic Safety
Administration (NHTSA).
Section VII of this preamble specifically requests comment on key
aspects of this proposed action and indexes comment solicitation to
promote public participation and facilitate our review of public
comments. Note that we are not limiting public participation to the
issues raised in this section and will respond to all comments within
the scope of this proposal. Rather, we are highlighting aspects of the
proposal for which public input would be particularly helpful in
determining whether and in what respects to finalize this proposed
action.
B. Need for Regulatory Action
Immediately upon taking office, President Trump established new
Executive Branch priorities for energy, transportation, and consumer
choice and committed to ensuring regulations remain within
constitutional and statutory bounds. On January 20, 2025, the President
issued an Executive Order titled ``Unleashing American Energy'' to
address the burdens placed by unnecessary regulations on energy
affordability, job creation, and national security.\3\ As relevant
here, the President directed the EPA Administrator to submit
recommendations to the Director of OMB on the legality and continuing
applicability of the 2009 Endangerment Finding.\4\ On February 19,
2025, the President issued an Executive Order titled ``Ensuring Lawful
Governance and Implementing the President's `Department of Government
Efficiency' Deregulatory Initiative'' that further instructed agencies,
including the EPA, to review existing regulations for consistency with
the Constitution and the best reading of the authorizing statute.\5\
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\3\ Executive Order 14154, 90 FR 8353 (Jan. 29, 2025).
\4\ Id. Sec. 6(f).
\5\ Executive Order 14219, 90 FR 10583 (Feb. 25, 2025).
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Upon confirmation by the Senate, Administrator Lee Zeldin committed
the EPA to prioritizing its core statutory mission and ensuring that
all regulatory actions are clearly grounded in statutory authority and
the best reading of the law. As part of these efforts, and consistent
with the ``Unleashing American Energy'' Executive Order, the
Administrator initiated a review of the legality and applicability of
the Endangerment Finding. On February 19, 2025, the Administrator
submitted a memorandum to the OMB Director recommending that the EPA
reconsider the Endangerment Finding to address legal and scientific
developments that appear to undermine the bases for that action and
subsequent regulations.\6\ The Administrator noted that recent Supreme
Court decisions, including Loper Bright, West Virginia, UARG, and
Michigan v. EPA, 576 U.S. 743 (2015), provided new guidance on how we
should interpret and apply the statutes Congress entrusted us to
administer.\7\ The Administrator further noted that the Endangerment
Finding recognized significant uncertainties in its conclusions and
assumptions that should be evaluated in light of more recent empirical
data and scientific
[[Page 36292]]
evidence.\8\ Accordingly, the Administrator announced on March 12,
2025, that the EPA would reconsider the Endangerment Finding and
subsequent actions to determine whether our GHG regulations have an
adequate statutory basis and to seek public input on developments since
2009.\9\
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\6\ Memorandum from Lee Zeldin, Administrator, Environmental
Protection Agency, to Russell Vought, Director, Office of Management
and Budget (Feb. 19, 2025) (Feb. 19, 2025 Memo), available in the
docket for this rulemaking.
\7\ Id. at 1.
\8\ Id. at 8.
\9\ ``Trump EPA Kicks Off Formal Reconsideration of Endangerment
Finding with Agency Partners'' (Mar. 12, 2025), available at https://www.epa.gov/newsreleases/trump-epa-kicks-formal-reconsideration-endangerment-finding-agency-partners.
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As part of this reconsideration, the EPA closely examined
applicable law, including judicial precedents and interpretive aids
bearing on the meaning of CAA section 202(a) and related statutory
provisions. We also reviewed actions taken to regulate GHG emissions
from new motor vehicles and new motor vehicle engines since 2009,
assessed the costs and non-cost adverse impacts of these GHG emission
standards, and evaluated the effectiveness of these GHG emission
standards in reducing the dangers identified in the Endangerment
Finding, that is, in mitigating the impacts anticipated to result from
elevated global GHG concentrations in the upper atmosphere.
Furthermore, the Administrator reviewed available information,
including the most recently available science, bearing on the
assumptions and conclusions in the Endangerment Finding, the impacts of
global GHG concentrations on public health and welfare in the United
States, and the relative contribution of domestic emissions from new
motor vehicles and engines to global GHG concentrations. As part of
that review, the Administrator received and evaluated the draft report
submitted by the U.S. Department of Energy (DOE) Climate Working Group
(CWG) to Secretary of Energy Christopher Wright on May 27, 2025, titled
``Impacts of Carbon Dioxide Emissions on the U.S. Climate'' (2025 CWG
Draft Report). The 2025 CWG Draft Report analyzes empirical data, peer-
reviewed studies, and available scientific information bearing on
direct human influence on ecosystems and climate, climate response to
CO2 emissions, and impacts on ecosystems and society.\10\
The Administrator also considered available assessments by the U.S.
Government and relevant international bodies, including the Third,
Fourth, and Fifth National Climate Assessments (NCAs) reported by the
U.S. Global Change Research Program (USGCRP) \11\ and the Fifth
Assessment Report (AR5) and Sixth Assessment Report (AR6) by the United
Nations Intergovernmental Panel on Climate Change (IPCC).\12\ As
discussed in section IV.B of this preamble, the Administrator also
considered critiques of the NCAs, and the Fifth NCA in particular, and
reviewed these analyses for consistency with OMB information quality
guidelines \13\ and the transparency and reliability requirements of
Executive Order 14303, ``Restoring Gold Standard Science.'' \14\
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\10\ The 2025 CWG Draft Report was provided to the EPA on May
27, 2025, and was reviewed and relied upon in formulating this
proposal. The EPA understands that DOE is releasing an updated
version of the CWG draft report and seeking public comment on the
updated report, which includes additional information and
typographical corrections that the EPA did not rely upon in
formulating this proposal. Interested parties may review and comment
on the updated version of the CWG draft report for consideration as
part of DOE's efforts through the docket available at https://www.energy.gov/topics/climate.
\11\ Created by the Global Change Research Act of 1990, Public
Law 101-606, 104 Stat. 3096, the USGCRP reports an NCA at least
every four years to Congress and the President that must (1)
integrate, evaluate, and interpret the findings of the Program and
discuss the scientific uncertainties with such findings; (2) analyze
the effects of global change on the natural environment,
agriculture, energy production and use, land and water resources,
human health and welfare, human social systems, and biological
diversity; and (3) analyze current trends in global change, both
human-induced and natural, and project major trends for the
subsequent 25 to 100 years. See 15 U.S.C. 2936.
\12\ The IPCC invites participation by members of the United
Nations and World Meteorological Organization and summarizes
available literature on climate science but does not conduct its own
research. See United Nations Intergovernmental Panel on Climate
Change, About the IPCC, available online at https://www.ipcc.ch/about/.
\13\ ``Guidelines for Ensuring and Maximizing the Quality,
Objectivity, Utility, and Integrity of Information Disseminated by
Federal Agencies; Republication,'' 67 FR 8452 (Feb. 22, 2002).
\14\ 90 FR 22601 (May 29, 2025).
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The Administrator's review of the relevant information, including
scientific literature, gave rise to serious concerns that our actions
taken to regulate GHG emissions from new motor vehicles and engines
exceed our statutory authority under CAA section 202(a) and are
otherwise inappropriate. Continuing to impose billions of dollars in
regulatory costs on American businesses and consumers without an
adequate legal basis would threaten to undermine public confidence in
our activities and commitment to fulfilling the Agency's core mission:
protecting human health and the environment. The EPA has expended
significant resources implementing the GHG regulatory program for
mobile sources and attempting to expand its GHG regulatory program to
stationary sources with limited success in the courts and no apparent
real-world results, often at the expense of programs that fall squarely
within our statutory authority. Prompt action is needed to address
these concerns with the benefit of public participation.
Relatedly, the Administrator has serious concerns that many of the
scientific underpinnings of the Endangerment Finding are materially
weaker than previously believed and contradicted by empirical data,
peer-reviewed studies, and scientific developments since 2009. This
proposal seeks public comment on these developments for the first time.
Prompt action is needed to address these concerns, and the
Administrator requests stakeholder input on the continuing vitality of
the assumptions, predictions, and conclusions animating the
Endangerment Finding.
C. Summary of the Major Provisions in This Proposed Action
If finalized, this action would rescind the 2009 Endangerment
Finding for GHGs emitted by new motor vehicles and new motor vehicle
engines under CAA section 202(a) (74 FR 66496). If finalized, this
action would also rescind denials of petitions for reconsideration of
the Endangerment Finding in 2022 and 2010 entitled ``Endangerment and
Cause or Contribute Findings for Greenhouse Gases Under Section 202(a)
of the Clean Air Act; Final Action on Petitions,'' 87 FR 25412 (Apr.
29, 2022), and ``EPA's Denial of the Petitions to Reconsider the
Endangerment and Cause or Contribute Finding for Greenhouse Gases Under
Section 202(a) of the Clean Air Act,'' 75 FR 49556 (Aug. 13, 2010).\15\
Although the 2022 and 2010 petition denials have no prospective legal
effect, we propose to rescind them for the sake of consistency and to
ameliorate potential confusion regarding the EPA's proposed action. As
explained later in this preamble, the denials reflect many of the same
legal and scientific flaws we propose to correct by rescinding the
Endangerment Finding. We seek comment on the impact of the denials, if
any, and on whether the denials were legally flawed for additional
reasons not explicitly explored in this proposal. In addition, as a
result of these proposed changes, we would no longer have a basis for
issuing or retaining GHG emission standards for new motor vehicles and
new motor vehicle engines, including
[[Page 36293]]
for MYs that have completed manufacture but are subject to ongoing
obligations. As discussed elsewhere in this preamble, the EPA is
reconsidering additional endangerment findings and GHG emission
standards issued under distinct provisions of the CAA in separate
rulemakings and is not reopening or proposing to modify those
additional findings and standards in this proceeding.
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\15\ The 2022 petition denials included a notice of decision in
the Federal Register (87 FR 25412), brief letters communicating the
denials to the petitioners, and a decision document entitled ``EPA's
Denial of Petitions Relating to the Endangerment and Cause or
Contribute Findings for Greenhouse Gases Under Section 202(a) of the
Clean Air Act'' (Apr. 21, 2022) (2022 Denial), available online at
https://www.epa.gov/system/files/documents/2022-04/decision_document.pdf.
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In connection with the proposed rescission of the Endangerment
Finding, if finalized, this action would remove all existing
regulations that require new motor vehicle and new motor vehicle engine
manufacturers to measure, report, or comply with GHG emission
standards. Specifically, the EPA proposes to remove regulations in 40
CFR parts 85, 86, 600, 1036, and 1037 pertaining to the control of GHG
emissions from light-, medium-, and heavy-duty vehicles and engines,
including emission standards, test procedures, averaging, banking, and
trading requirements (ABT), reporting requirements, and fleet-average
emission requirements.\16\ As a result of these proposed changes, motor
vehicle and engine manufacturers would no longer have future or current
obligations for the measurement, control, or reporting of GHG emissions
for any vehicle or engine, including for previously manufactured MYs.
However, we are not proposing to reopen or modify any regulations
necessary for criteria pollutant and air toxic measurement and
standards, Corporate Average Fuel Economy (CAFE) testing, and
associated fuel economy labeling requirements. We seek comment on
whether any elements of the regulations, test procedures, or GHG
emission models that are proposed for removal should remain to support
programs unrelated to the GHG emission standards and why the
preservation of such an element is necessary to support the unrelated
program or programs.
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\16\ ``Light-Duty Vehicle Greenhouse Gas Emission Standards and
Corporate Average Fuel Economy Standards,'' 75 FR 25324 (May 7,
2010); ``Greenhouse Gas Emissions Standards and Fuel Efficiency
Standards for Medium- and Heavy-Duty Engines and Vehicles,'' 76 FR
57106 (Sept. 15, 2011); ``2017 and Later Model Year Light-Duty
Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy
Standards,'' 77 FR 62624 (Oct. 15, 2012); ``Greenhouse Gas Emissions
and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and
Vehicles-Phase 2,'' 81 FR 73478 (Oct. 25, 2016); ``The Safer
Affordable Fuel-Efficient (SAFE) Vehicles Rule for Model Years 2021-
2026 Passenger Cars and Light Trucks,'' 85 FR 24174 (Apr. 30, 2020);
``Revised 2023 and Later Model Year Light-Duty Vehicle Greenhouse
Gas Emissions Standards,'' 86 FR 74434 (Dec. 30, 2021); ``Multi-
Pollutant Emissions Standards for Model Years 2027 and Later Light-
Duty and Medium-Duty Vehicles,'' 89 FR 27842 (Apr. 18, 2024);
``Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles-Phase
3,'' 89 FR 29440 (Apr. 22, 2024).
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II. Background
A. The EPA's Historical Approach to CAA Section 202(a)
Congress originally enacted the language that became CAA section
202(a) as part of the Motor Vehicle Pollution Control Act of 1965,
which required the Secretary of Health, Education, and Welfare to
``prescribe . . . standards, applicable to the emission of any kind of
substance, from any class or classes of new motor vehicles or new motor
vehicle engines, which in his judgment cause or contribute to, or are
likely to cause or contribute to, air pollution which endangers the
health or welfare of any persons.'' \17\ Congress retained this
language, while adding additional requirements for the content of
emission standards, in the Air Quality Act of 1967,\18\ and, later,
incorporated it into the Clean Air Act of 1970, which transferred the
Secretary's regulatory authority to the newly created EPA.\19\
Separately, the 1970 CAA addressed emissions from existing vehicles and
engines, stationary sources, and aircraft engines.\20\ As subsequently
amended, CAA section 202(a) has remained a critical part of the
comprehensive national framework for regulating air pollution from
mobile sources, and new motor vehicles and new motor vehicle engines in
particular, under Title II of the CAA.\21\
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\17\ Public Law 89-272, 202(a), 79 Stat. 992, 992-93 (1965).
\18\ Public Law 90-148, 202(a), 81 Stat. 485, 499 (1967).
\19\ Public Law 91-604, 84 Stat. 1690 (1970).
\20\ Id.
\21\ In the Clean Air Act Amendments of 1977, Congress replaced
the phrase ``which endangers the public health or welfare'' with
``which may reasonably be anticipated to endanger public health or
welfare.'' Public Law 95-95, 401(d)(1), 91 Stat. 685, 791 (1977).
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In its first four decades administering the statute, the EPA
applied CAA section 202(a) to local and regional air pollution problems
through rulemakings that prescribed standards and set forth the
Administrator's findings that the relevant air pollutant emissions
cause, or contribute to, air pollution which may reasonably be
anticipated to endanger public health or welfare.\22\ As explained in
the following subsections, the EPA maintained this approach through
2008 and never sought to invoke CAA section 202(a) to regulate in
response to global climate change concerns.
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\22\ See 74 FR 66501, 66527, 66538, 66543 (acknowledging this
regulatory history).
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B. Petitions for Rulemaking and Massachusetts v. EPA
In October 1999, a coalition of 19 environmental organizations
petitioned the EPA to regulate the emission of four GHGs--
CO2, methane, N2O, and HFCs--from new motor
vehicles and engines under CAA section 202(a)(1). Petitioners claimed
that these four GHGs were ``air pollutant[s]'' under CAA section
302(g), significantly contributed to global climate change, and met the
statutory standard for regulation under CAA section 202(a)(1). Thus,
petitioners claimed that the EPA had the authority and obligation to
find that GHG emissions from new motor vehicles and engines cause, or
contribute to, air pollution which may reasonably be anticipated to
endanger public health or welfare and to prescribe standards in
response.
In September 2003, after receiving and responding to nearly 50,000
public comments on the relevant issues, the EPA denied the 1999
petitions in a final action titled ``Control of Emissions from New
Highway Vehicles and Engines,'' 68 FR 52922 (Sept. 8, 2003) (2003
Denial). The 2003 Denial asserted three primary reasons for denying the
petitions. First, after ``examin[ing] the fundamental issue of whether
the CAA authorizes the imposition of control requirements'' to ``reduce
the risk of global climate change,'' we concluded that ``CO2
and other GHGs cannot be considered `air pollutants' subject to the
CAA's regulatory provisions for any contribution they may make to
global climate change.'' 68 FR 52925. Citing the Supreme Court's
decision in FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120
(2000), we noted that the CAA does not address GHGs as a regulatory
matter, including in recent amendments, and that ``EPA has used these
provisions to address air pollution problems that occur primarily at
ground level or near the surface of the earth.'' 68 FR 52926. On this
basis, we concluded that GHGs ``are not air pollutants under the CAA's
regulatory provisions, including sections 108, 109, 111, 112, and 202''
because they categorically are not ``air pollutant[s]'' under the Act-
wide definition in CAA section 302(g). 68 FR 52928. Second, we
concluded that regulating GHG emissions from motor vehicles and engines
under the CAA would interfere with NHTSA's separate authority to
implement fuel economy standards. 68 FR 52929. Finally, we asserted
that regulating GHG emissions from motor vehicle engines under the CAA
would
[[Page 36294]]
undermine the President's overall policy approach of addressing global
climate change through voluntary actions and incentives, the promotion
of further research and technologies, and international negotiations.
68 FR 52930-31.
In Massachusetts, the Supreme Court narrowly reversed the D.C.
Circuit's decision to uphold the EPA's denial of the 1999 petitions for
rulemaking.\23\ The Court took particular issue with the EPA's reading
of the Act-wide definition in CAA section 302(g), ruling that ``[t]he
Clean Air Act's sweeping definition of `air pollutant' . . . embraces
all airborne compounds of whatever stripe'' and provided no textual
basis for excluding CO2 or the three other GHGs raised in
the petitions for rulemaking. 549 U.S. at 528-29. The Court also
addressed EPA's reliance on Brown & Williamson, which the majority
construed as having found no congressional intent to ban the sale of
tobacco products outright because such an application of the relevant
statute would have been highly unlikely and because the Food and Drug
Administration (FDA) had expressly refused to assert such authority in
the past. Id. at 530-31. In contrast, in Massachusetts, the Court found
that the CAA did not reflect a congressional intent to categorically
exclude GHGs and, citing several Agency memoranda, that we had not
similarly foresworn all authority to regulate GHGs as a categorical
matter. Id. Notably, the Court expressly declined to decide whether the
EPA was required to issue an affirmative endangerment finding as to GHG
emissions under the standard set out in CAA section 202(a). Id. at 534
(``We need not and do not reach the question whether on remand EPA must
make an endangerment finding.''). Nor did the Court address ``whether
policy concerns can inform EPA's actions in the event that it makes
such a finding.'' Id. at 534-35. Rather, the Court held that we must
respond to the petitions by deciding whether GHG emissions from new
motor vehicles and engines meet the standard for regulation in CAA
section 202(a) or whether the science was too uncertain to make any
determination, and that, in doing so, we must ``ground [our] reasons
for action or inaction in the statute.'' Id. at 535.\24\
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\23\ The D.C. Circuit majority had upheld the denial on the
merits because ``the EPA Administrator properly exercised his
discretion under Sec. 202(a)(1) in denying the petition for
rulemaking.'' Massachusetts v. EPA, 415 F.3d 50, 58 (D.C. Cir.
2005). The dissent argued that CAA section 202(a)'s breadth provided
the EPA sufficient authority to regulate GHGs, that more specific
authorization was not required, and that the EPA's policy
justifications were inadequate reasons to deny the petitions. Id. at
67-82 (Tatel, J., dissenting).
\24\ Writing for four members of the Court, Chief Justice
Roberts would have dismissed the petitions for review for lack of
Article III standing. 549 U.S. at 535 (Roberts, C.J., joined by
Scalia, Thomas, and Alito, J.J., dissenting). Writing for the same
four members of the Court, Justice Scalia would have denied the
petitions on the grounds that the Administrator reasonably exercised
judgment in declining to regulate and that CAA section 302(g)'s
definition of ``air pollutant'' does not clearly encompass
CO2 and other GHGs that naturally occur in the ambient
air. 549 U.S. at 549 (Scalia, J., joined by Roberts, C.J., and
Thomas and Alito, J.J., dissenting).
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C. The 2009 Endangerment Finding
The EPA responded to the Supreme Court's decision in Massachusetts
by issuing an advanced notice of proposed rulemaking titled
``Regulating Greenhouse Gas Emissions Under the Clean Air Act,'' 73 FR
44354 (July 30, 2008) (2008 ANPRM). The Administrator began by noting
it was ``clear that if EPA were to regulate [GHG] emissions from motor
vehicles under the Clean Air Act,'' the interplay between CAA section
202(a) and similarly worded statutory provisions ``could result in an
unprecedented expansion of EPA authority that would have a profound
effect on virtually every sector of the economy and touch every
household in the land.'' 73 FR 44355. The Administrator cautioned that
because the CAA was ``originally enacted to control regional pollutants
that cause direct health effects,'' invoking authority to regulate GHG
emissions ``would inevitably result in a very complicated, time-
consuming, and, likely, convoluted set of regulations'' that ``would be
relatively ineffective at reducing [GHG] concentrations'' and have a
``potentially damaging effect on jobs and the U.S. economy.'' Id.
The 2008 ANPRM echoed the Administrator's concerns by seeking
public comment on invoking CAA section 202(a) to regulate new motor
vehicle and engine emissions in response to global climate change
concerns. We acknowledged that the CAA ``was not specifically designed
to address GHGs,'' 73 FR 44397, and that the EPA had historically
interpreted and applied its CAA regulatory authorities to address local
and regional air pollution, 73 FR 44408. We further noted that Congress
was considering legislation to address the Nation's response to global
climate change concerns and that, since Massachusetts, Congress had
passed and the President had signed into law the Energy Independence
and Security Act (EISA), which amended provisions applicable to the
EPA's Renewable Fuels Standard (RFS) program and NHTSA's CAFE standards
program. 73 FR 44398. Finally, we noted that the EPA had received
additional petitions to regulate stationary sources and additional
GHGs, including water vapor, all of which suggested that GHG emission
regulations could not readily be limited to new motor vehicles and
engines. 73 FR 44399 & n.26.
As to CAA section 202(a), the 2008 ANPRM set out a framework for
determining whether ``GHG emissions from new motor vehicles cause or
contribute to air pollution that may reasonably be anticipated to
endanger public welfare'' under CAA section 202(a)(1) or for
``explain[ing] why scientific uncertainty is so profound that it
prevents making a reasoned judgment on such a determination.'' 73 FR
44398, 44421. We reviewed available information for CO2,
methane, and N2O emissions and noted that HFCs, PFCs, and
SF6 are ``often grouped together'' and separately from the
rest ``because they contain fluorine, typically have large global
warming potentials, and are produced only through human activities.''
73 FR 44401-02.\25\ With respect to endangerment, we sought comment on
whether GHGs could properly be considered dangerous air pollution
because the potential health effects are indirect and the potential
welfare effects may be positive on balance. 73 FR 44427. In addition,
we sought comment on whether ``the unique characteristics and
properties of each GHG . . . as well as current and projected
emissions'' meant that each GHG should be analyzed individually or
whether certain GHGs other than CO2 were amenable to
grouping. 73 FR 44428. With respect to causation or contribution, we
presented motor vehicle and engine emissions data for each GHG
separately and noted that emission trends had diverged between
pollutants, with CO2 emissions, for example, generally
increasing since 1990 and N2O emissions, for example,
increasing from 1990 to 1995 and then falling substantially from 1995
to 2006 because of fuel and technology changes. 73 FR 44430. We also
presented extensive information on potential regulatory approaches that
could be triggered by a positive finding under CAA section 202(a),
including
[[Page 36295]]
approaches specific to particular GHGs. 73 FR 44438-63.
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\25\ In the 2008 ANPRM, the EPA noted that the most recently
available IPCC analysis concluded that ``[t]he anthropogenic
combined heating effect (referred to as forcing) of [methane],
N2O, HFCs, PFCs and SF6 is about 40% as large
as the CO2 cumulative heating effect since pre-industrial
times.'' 73 FR 44423.
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Following a change in administration, however, the EPA proposed in
April 2009 and finalized in December 2009 a much different approach to
analyzing GHG emissions from new motor vehicles and engines under CAA
section 202(a). In the Endangerment Finding, the Administrator found
that ``the science [was] sufficiently certain'' to compel an
affirmative determination and interpreted Massachusetts as ``allow[ing]
for the consideration only of science.'' 74 FR 66501. Relatedly, the
Administrator did not consider any of the implementation challenges or
options discussed in the 2008 ANPRM, asserting instead that CAA section
202(a) confers ``procedural discretion'' to issue standalone findings
without considering a regulatory response because the statute ``is
silent on this issue.'' Id. The Administrator also defined all six
``well-mixed'' GHGs collectively as the relevant ``air pollutants'' and
``air pollution'' for purposes of endangerment and causation or
contribution, meaning the Endangerment Finding did not need to address
the different characteristics or emission trends of any particular GHG.
74 FR 66516-21, 66536-57.
With respect to endangerment, the Administrator began by excluding
adaptation--human responses that reduce potential adverse impacts--and
mitigation--independent measures that reduce the causes of potential
adverse impacts--from the analysis of global climate change concerns.
74 FR 66513. The Administrator acknowledged that ``some level of
autonomous adaptation will occur'' and that ``this separation means
this approach may not reflect the actual conditions in the real world
in the future, because adaptation and/or mitigation may occur and
change the risks.'' Id. Nevertheless, the Administrator reasoned that
``it would be extremely hard to make a reasoned projection of human and
societal adaptation and mitigation responses'' because they are
``largely political'' or ``individual personal judgments.'' Id. Next,
the Administrator relied on IPCC Assessment Report 4 (AR4) projections
to find that global temperatures would likely increase between 1.8 to 4
degrees Celsius by 2100, with an uncertainty range of 1.1 to 6.4
degrees Celsius. 74 FR 66519. Operating within this analytical
framework, the Administrator found that elevated global concentrations
of GHGs from all foreign and domestic sources were responsible for
increased global temperatures that were responsible in turn for
indirect health risks driven by (1) more frequent heat waves; (2) air
quality effects, including increased formation of ozone, and (3)
broader societal impacts related to increased frequency and severity of
certain extreme weather events. 74 FR 66525.\26\ The Administrator also
found that GHG emissions could lead to welfare effects related to (1)
food production and agriculture; (2) forestry; (3) water resources; (4)
sea level rise; and (5) energy infrastructure and settlements, although
the evidence was uncertain for several categories that may see near-
term benefits. 74 FR 66531-35.\27\ Importantly, the Administrator
acknowledged that the understanding of public health and welfare in the
Endangerment Finding was atypical, particularly with respect to
considering indirect effects, but asserted the approach was necessary
given the ``unique'' challenge presented by global climate change. 74
FR 66527.
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\26\ The Administrator also noted that increased global
temperatures could lead to changes in certain food- and water-borne
pathogens and allergens (including increases in pollen resulting
from increased plant growth at higher concentrations of
CO2) but did ``not plac[e] primary weight on these
factors.'' 74 FR 66498, 66526.
\27\ The Administrator relied on welfare impacts to water
resources and sea level rise as providing ``the clearest and
strongest support for an endangerment finding.'' 74 FR 66534.
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With respect to contribution, the Administrator asserted broad
authority to interpret the statutory standard because ``[t]he language
of CAA section 202(a) is silent regarding how the Administrator is to
make her contribution analysis.'' 74 FR 66544. Exercising that putative
interpretive authority, the Administrator concluded that ``it is
reasonable to consider that lower percentages contribute than one may
consider when looking at a local or regional problem involving fewer
sources of emissions,'' 74 FR 66545, because ``all contributors must do
their part'' to avoid ``a tragedy of the commons, whereby no country or
source category would be accountable for contributing to the global
problem of climate change,'' 74 FR 66543. Next, the Administrator
relied on data showing that existing motor vehicles and engines emitted
four GHGs--CO2, methane, and N2O from engines, as
well as HFCs from air conditioning units--that accounted for 4.3
percent of global GHG emissions at the time. On that basis, the
Administrator found that GHG emissions from new motor vehicles and
engines ``contribute to the air pollution'' consisting of the six
``well-mixed'' GHGs previously identified as a danger to public health
or welfare. 74 FR 66537-39.
Crucially, the Endangerment Finding made clear that the EPA was
acting independently from any new congressional mandate. Rather, the
Administrator interpreted CAA section 202(a) as setting out a
standalone authority to issue findings that establish jurisdiction
without considering implementation concerns and purported to rest the
Endangerment Finding solely on a scientific judgment informed by the
record as assembled by the Agency in 2009.
D. Implementation of the 2009 Endangerment Finding
In the years since issuing the Endangerment Finding, the EPA has
promulgated GHG emission standards for various classes of new motor
vehicles and engines in reliance on the Endangerment Finding and, as
anticipated in the 2008 ANPRM, sought to expand the same analytical
framework to regulatory provisions governing existing vehicles,
stationary sources, aircraft, and oil and gas operations. For a full
accounting of GHG emission standards adopted since 2009 under CAA
section 202(a), see sections VI.B and VI.C of this preamble.
Following the Endangerment Finding, the EPA received multiple
petitions for reconsideration from industry groups, States, and various
organizations arguing that our approach in 2009 was legally and
scientifically flawed and that external assessments by the IPCC, among
others, had not adequately addressed recent criticisms of climate
change science. The EPA denied these consolidated petitions in 2010
without notice and comment. Reiterating the scientific assertions from
the technical support document (TSD) used in 2009, we emphasized that
we had conducted an independent review of outside assessments in
issuing the Endangerment Finding and asserted that the core conclusions
of the Endangerment Finding remained valid notwithstanding the flaws
raised by the petitioners. The EPA also issued a volume of response
documents defending the methodologies and experts relied upon and
concluded that no new information warranted reconsideration. 75 FR
49556.
In April 2022, the EPA denied, again without notice and comment, a
new round of petitions for reconsideration and rulemaking asserting
that the Endangerment Finding was legally and scientifically flawed and
undermined by more recent scientific assessments. We acknowledged that
several recent studies contradicted assessments by the USGCRP and IPCC
but reaffirmed our earlier position that such assessment reports are
entitled to greater weight
[[Page 36296]]
than dissenting views.\28\ We also considered criticisms of the EPA's
Social Cost of Carbon (SCC) methodology out of scope because ``the
social cost of carbon played no role in the 2009 Endangerment
Finding.'' \29\ We further acknowledged that severing the endangerment
and cause or contribute analysis from the development of subsequent
regulations had impacted the EPA's approach to GHG emission standards,
including because the Science Advisory Board (SAB) did not have the
opportunity to review the Endangerment Finding as would otherwise have
been required by the CAA.\30\ Nevertheless, we reaffirmed our position
that CAA section 202(a) grants ``procedural discretion'' to issue
findings and emission standards separately and ``decline[d] to exercise
that discretion'' differently.\31\
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\28\ 2022 Denial at 15-17.
\29\ Id. at 30.
\30\ Id. at 36 (noting that 42 U.S.C. 4365(c)(1) requires SAB
consultation for a ``standard'' promulgated under CAA section 202(a)
but asserting that requirement does not extend to ``findings''
issued under the same provision).
\31\ Id. at 39.
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E. Reconsideration of the 2009 Endangerment Finding
Since the EPA published the 2009 Endangerment Finding, there have
been developments in innovation, science, economics, and mitigation, as
well as significant Supreme Court decisions that provide new guidance
on how federal agencies should interpret the statutory provisions that
Congress has tasked them with administering.\32\ Accordingly, the
Administrator has now determined that the Endangerment Finding should
be reconsidered to address legal and scientific developments that
present reason to question the ongoing validity and reliability of its
conclusions and to subject these important issues to public comment for
the first time since 2009.
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\32\ See Feb. 19, 2025 Memo at 1.
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In initiating reconsideration, the Administrator explored all
findings, support, questions, and ambiguities contained within the
science relied upon by the Endangerment Finding. As acknowledged in the
Endangerment Finding and recent reports, there are significant
questions and ambiguities presented by both the observable realities of
the past nearly two decades and the recent findings of the scientific
community, including those summarized in the 2025 CWG Draft Report.
There may also be as-yet-unidentified issues or discrepancies present
in the underlying TSD and scientific justifications offered in the
Endangerment Finding. When confronted with science offering a diverse
array of conclusions, methodologies, and explanations, the
Administrator strove to inform his judgment to the most impartial
extent possible. A more detailed discussion of the available climate
science can be found in section IV.B.
III. Legal Framework for Proposed Action
A. Proposed Rescission of Endangerment Finding
The statutory authority for this proposed action is the same as
that relied upon in the prior actions at issue: CAA section 202(a)(1),
which requires the Administrator to ``prescribe'' and ``from time to
time revise . . . standards'' for certain air pollutants emitted by new
motor vehicles and new motor vehicle engines ``in accordance with the
provisions of this section.'' \33\ Unless provided otherwise by
statute, an agency may revise or rescind prior actions so long as it
acknowledges the change in position, provides a reasonable explanation
for the new position, and considers legitimate reliance interests in
the prior position.\34\
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\33\ 42 U.S.C. 7521(a)(1).
\34\ See Wages & White Lion, 145 S. Ct. 898; FCC v. Fox
Television Stations, Inc., 556 U.S. 502 (2009); Motor Vehicle Mfrs.
Ass'n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29 (1983); Clean
Air Council v. Pruitt, 862 F.3d 1, 8 (D.C. Cir. 2017) (``Agencies
obviously have broad discretion to reconsider a regulation at any
time.'').
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The EPA proposes that nothing in the language of the statute
prohibits or conditions our general authority to rescind prior actions.
CAA section 202(a)(1) grants the Administrator discretion to ``revise''
standards prescribed ``in accordance with the provisions of this
section'' and does not require retaining the same level of stringency
when revising or rescinding existing standards. Moreover, the statute
neither authorizes the Administrator to issue standalone findings that
trigger a duty to regulate nor prohibits the Administrator from
rescinding such findings. Rather, CAA section 202(a)(1) requires the
Administrator to prescribe standards for emissions of any air pollutant
by classes of new motor vehicles or engines when, in his judgment,
emissions of such air pollutant by such classes of new motor vehicles
or engines ``cause, or contribute to, air pollution which may
reasonably be anticipated to endanger public health or welfare.''
Notably, the EPA has consistently assumed that it has the statutory
authority to rescind the Endangerment Finding in reviewing the merits
of petitions for reconsideration since 2009 and did not state that we
lack such reconsideration authority.\35\
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\35\ See, e.g., 2022 Denial at 7-10 (denying mandatory
reconsideration under CAA section 307(d) and reviewing the petitions
on the merits as rulemaking petitions under APA section 553(e)); 75
FR 49560-63 (denying mandatory reconsideration under CAA section
307(d) without asserting that the EPA lacked statutory authority to
rescind or revise the Endangerment Finding).
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The EPA acknowledges that rescinding the Endangerment Finding as
proposed would involve significant changes to the legal interpretations
adopted in the Endangerment Finding and retained in subsequent actions.
For example, if finalized, the interpretation of CAA section 202(a)
proposed in this action would preclude the EPA from issuing standalone
endangerment and contribution findings and would instead require the
Agency to make findings for particular air pollutant emissions and
classes of new motor vehicles and engines as an integral step in a
rulemaking to prescribe standards for such emissions and classes,
consistent with our decades-long practice prior to 2009 in regulating
non-GHG air pollutants. Furthermore, if finalized, the interpretation
of CAA section 202(a) proposed in this action would reverse the basis
for the Endangerment Finding by concluding that global climate change
concerns cannot satisfy the statutory standard for regulation under CAA
section 202(a). For discussion of our proposed interpretation of CAA
section 202(a) and related statutory provisions, see section IV.A of
this preamble. For discussion of our alternative proposal to rescind
the Endangerment Finding because the EPA exercised its authority under
CAA section 202(a) unreasonably and because the Administrator no longer
has confidence in the assumptions, methodology, and conclusions in the
Endangerment Finding in light of the scientific record, see section
IV.B of this preamble.
The EPA is also proposing additional statutory and policy
rationales for repealing the GHG emission standards currently in effect
for new motor vehicles and engines separate and apart from the proposed
rescission of the Endangerment Finding. If finalized, these alternative
rationales would change the novel position taken in rulemakings since
2009 to prescribe and revise GHG emission standards under CAA section
202(a).\36\ For example, if finalized, our proposal to determine that
there is no ``requisite technology'' for
[[Page 36297]]
vehicle emission control capable of having a measurable impact on the
dangers identified in the Endangerment Finding would preclude any GHG
emission standards from going into effect. Furthermore, if finalized,
our proposal to determine that the GHG emission standards harm public
health and welfare on balance would make it unreasonable and contrary
to the objectives of the statute to issue and retain such standards.
See section V of this preamble for further discussion of these
additional rationales and the Agency's prior positions.
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\36\ 75 FR 25324 (May 7, 2010); 76 FR 57106 (Sept. 15, 2011); 77
FR 62624 (Oct. 15, 2012); 81 FR 73478 (Oct. 25, 2016); 85 FR 24174
(Apr. 30, 2020); 86 FR 74434 (Dec. 30, 2021); 89 FR 27842 (Apr. 18,
2024); 89 FR 29440 (Apr. 22, 2024).
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The EPA acknowledges that repealing the GHG emission standards
based on the proposed rescission of the Endangerment Finding would
depart from our position in rulemakings since 2009 that prescribed and
revised GHG emission standards for light- and medium-duty vehicles and
heavy-duty vehicles and engines under CAA section 202(a). If finalized
as proposed, the rescission would eliminate the statutory basis for
those standards because we relied on the Endangerment Finding in each
rulemaking to invoke our authority under CAA section 202(a) without
making the required findings for GHGs emitted by the class or classes
of new motor vehicles or engines at issue in each rulemaking. See
section VI of this preamble for further discussion of each prior
rulemaking and the regulatory changes that would be necessary to repeal
all GHG emission standards currently in effect for new motor vehicles
and engines on any of the bases proposed in this action.
As discussed throughout this preamble, the EPA is proposing these
changes to comply with limits on our statutory authority under the best
reading of CAA section 202(a), respond to legal and scientific
developments that undermine the conclusions and assumptions of the
Endangerment Finding, and realign Agency resources to prioritize core
statutory responsibilities. Importantly, the Nation's policy response
to global climate change concerns was a major issue in the 2024
presidential election, in which voters were presented with distinct
legal and policy approaches and elected a candidate promising a change
in policy. Under these circumstances, the election of a new
Administration is an independent and sufficient basis for changing
legal interpretation and policy within the boundaries set by
statute.\37\ Democratic accountability is essential to the exercise of
delegated authority by administrative agencies,\38\ and retaining the
Endangerment Finding without clear statutory authority would frustrate,
not promote, constitutional values and the rule of law. If the EPA
lacks authority to retain the Endangerment Finding under the best
reading of CAA section 202(a), the statute controls regardless of
policy preferences.
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\37\ See State Farm, 463 U.S. at 59 (Rehnquist, J., concurring
in part and dissenting in part); PETA v. USDA, 918 F.3d 151, 158
(D.C. Cir. 2019) (``new administrations are entitled to reevaluate
and modify agency practices, even longstanding ones''); Nat'l Ass'n
of Home Builders v. EPA, 682 F.3d 1032, 1043 (D.C. Cir. 2012) (``the
inauguration of a new President and the confirmation of a new EPA
Administrator'' went ``a long way toward explaining why EPA''
changed policy).
\38\ See, e.g., U.S. Telecom Ass'n v. FCC, 855 F.3d 381 (D.C.
Cir. 2017) (Brown, J., dissenting from denial of rehearing en banc);
Elena Kagan, Presidential Administration, 114 Harv. L. Rev. 2245,
2252-53, 2332-34 (2001).
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The EPA seeks comment on the nature and extent of any reliance
interests that may have arisen from our assertion of regulatory
authority over GHG emissions from new motor vehicles and engines and is
committed to assessing any such interests, determining whether they are
significant, and weighing such interests against competing rationales,
as required by law.\39\
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\39\ See, e.g., DHS v. Regents of Univ. of Cal., 591 U.S. 1, 33
(2020).
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Specifically, we seek comment on whether regulated parties have any
significant reliance interests in our GHG emission standards for new
motor vehicles and new motor vehicle engines. We are aware that
manufacturers, importers, and sellers have already expended resources
complying with GHG emission standards for MYs 2012 through 2026, and
that consumer prices for vehicles in these MYs reflect the costs of
such compliance. Because many compliance costs are incurred as part of
research and development and during manufacturing, with the notable
exception of the need to purchase compliance credits, this proposed
action would have limited impacts on MYs 2012 to 2024, greater impacts
for MYs 2024-2026, and would entirely relieve future regulatory
obligations for MY 2027 and beyond. As discussed in sections VI.B and
VI.C of this preamble, we are confident that the Agency has adequate
regulatory tools to address transitional compliance concerns and note
that this proposed action would not, if finalized, mandate any
particular response by regulated parties. We are also aware that
regulated parties may have reliance interests in national uniformity
and CAA preemption with respect to emission standards for new motor
vehicles and engines. As discussed in section VI.A of this preamble,
CAA section 209(a) and other applicable sources of federal preemption
would continue to apply, and we would retain our authority to regulate
emissions, including emissions of the six ``well-mixed'' GHGs addressed
in the Endangerment Finding, under circumstances that meet the standard
for regulation under CAA section 202(a). We seek comment on each of
these rationales, including on whether any reliance interests in
national uniformity and preemption would support finalizing or not
finalizing the proposed action, or adopting certain rationales and not
finalizing other rationales. We further seek comment on the continued
preemptive effect of the CAA in the event that the EPA finalizes the
proposed rescission or any of the alternatives discussed herein (or in
the event that the Agency determines that it lacks authority at the
present time to regulate GHG emissions under one or more provisions of
the CAA for any reason). As a general matter, we also seek comment on
how we should repeal the Endangerment Finding and regulations if the
decision is made to proceed with the proposed repeals, including under
any of the options set out in this proposal or any additional grounds
and means.
In addition, the EPA seeks comment on whether regulated parties and
other stakeholders have significant reliance interests in GHG emission
standards for new motor vehicles and engines. This proposed action
would make only minor conforming adjustments to regulatory provisions
for criteria pollutants and air toxics, thereby leaving most emission
standards for new motor vehicles and engines in place. Nor would this
proposed action impact separate economy and fuel-efficiency standards
that have the effect of reducing GHG emissions per mile traveled from
new motor vehicles and engines, including standards issued by NHTSA. As
explained in section IV.A.1 of this preamble, we now believe that
regulating GHG emissions based on global climate change concerns
exceeds our statutory authority under CAA section 202(a) and, as such,
propose that reliance interests alone would not justify retaining the
GHG emission standards that we lacked authority to prescribe. As
discussed in section IV.A.2 of this preamble, potential dangers from
local or regional exposure to the six ``well-mixed'' GHGs covered by
the Endangerment Finding are regulated separately under specific grants
of statutory authority. And as discussed in section V of this preamble,
we now believe that GHG emission standards for new motor vehicles and
engines may harm public health and
[[Page 36298]]
welfare without having any measurable impact on the global climate
change concerns identified in the Endangerment Finding. We seek comment
on potential reliance interests in GHG emission standards for global
climate change concerns under CAA section 202(a), including on whether
such reliance justifies retaining standards in the absence of statutory
authority and the extent to which potential dangers are addressed, or
could be addressed, under more specific authorities.
The EPA recognizes that we have relied in part on the Endangerment
Finding in issuing subsequent endangerment findings and GHG regulations
under other CAA provisions, including for certain stationary sources
and aircraft engines. The Supreme Court has since vacated several of
these actions, including GHG regulations for existing sources in the
fossil-fuel fired power plant source category under CAA section 111(d)
and for permitted sources under CAA Title V.\40\ For those actions that
remain in effect, we have initiated or intend to initiate separate
rulemakings that will address any overlapping issues.
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\40\ See West Virginia, 597 U.S. 697; UARG, 573 U.S. 302.
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Among other concerns with the Endangerment Finding, we believe that
severing consideration of endangerment and causation or contribution
from the appropriate regulatory response under CAA section 202(a)
resulted in broad statements that did not account for the statutory
language in CAA section 202(a)(1) on which the Endangerment Finding
purported to rely. Congress used different authorizing language to
address distinct issues for stationary sources regulated under CAA
section 111 and aircraft engines regulated under CAA section 231. In
reconsidering actions taken under these authorities, we intend to
address prior findings and standards in light of the particular
statutory language, policy concerns, and scientific information
relevant to each context. In this proposed action, we seek comment on
reliance interests in the Endangerment Finding and GHG emission
standards issued under CAA section 202(a) and reserve the right to
direct out of scope comments to the appropriate rulemaking docket for
the applicable regulatory action.
B. Proposed Amendments to New Motor Vehicle and Engine Regulations
As noted above, CAA section 202(a)(1) directs the Administrator to
prescribe ``standards applicable to the emission of any air pollutant
from any class or classes of new motor vehicles or new motor vehicle
engines, which in his judgment cause, or contribute to, air pollution
which may reasonably be anticipated to endanger public health or
welfare.'' This core directive has remained substantially the same
since Congress enacted the Motor Vehicle Pollution Control Act of
1965.\41\ Thus, a necessary condition to regulating emissions from new
motor vehicles and engines is a finding--an ``endangerment finding''--
that emissions of an air pollutant from a class or classes of new motor
vehicles or engines cause or contribute to air pollution which may
reasonably be anticipated to endanger public health or welfare.
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\41\ Public Law 89-272, 79 Stat. 992-93.
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For the reasons discussed in section IV of this preamble, we are
proposing to rescind the Endangerment Finding for GHG emissions from
new motor vehicles and new motor vehicle engines and, on that basis, to
repeal all existing GHG emission standards for passenger cars, light-
duty trucks, motorcycles, buses, medium-duty vehicles, and heavy-duty
vehicles and engines. The Endangerment Finding has served as the EPA's
basis for regulating GHG emissions from new motor vehicles and new
motor vehicle engines since 2009. Absent findings of endangerment and
causation or contribution, the EPA lacks statutory authority to
prescribe standards for those emissions under CAA section 202(a)(1). We
propose that when the EPA rescinds an endangerment finding for an air
pollutant, it must cease prescribing and enforcing standards applicable
to the emission of that pollutant from new motor vehicles or new motor
vehicle engines and should rescind existing standards no longer
authorized by statute.
For the reasons discussed in section V of this preamble, we are
also proposing additional bases to repeal GHG emission standards even
if the Endangerment Finding were to remain in place. We propose that
regardless of whether GHG emissions trigger the standard for regulation
in CAA section 202(a)(1), our authority to prescribe and enforce
emission standards for GHGs is limited by the language of CAA section
202(a)(2) and must be exercised in a reasonable manner that furthers,
rather than burdens, the health and welfare of all Americans.
Accordingly, the EPA is proposing to repeal all standards and
associated test procedures adopted to limit the emission of GHGs under
CAA section 202(a) for highway light-, medium-, and heavy-duty vehicles
and engines. The EPA notes that, for light-duty vehicles, the Energy
Policy and Conservation Act of 1975 (EPCA) and the 2007 EISA authorize
NHTSA to administer the CAFE program and fuel economy labeling program.
These statutes also direct the EPA to determine compliance values for
manufacturers subject to the CAFE program and the fuel economy labeling
program. Importantly, these statutory obligations are distinct from the
EPA's authority under CAA section 202(a) and from the EPA's decisions
since 2009 to regulate GHG emissions under CAA section 202(a). As
explained in section VI of this preamble, we are retaining and not
proposing to reopen regulatory provisions related to our statutory
roles in these NHTSA programs. Likewise, we are retaining and not
proposing to reopen any criteria pollutant and air toxics standards for
highway light-, medium-, and heavy-duty vehicles and engines under CAA
section 202(a).
IV. Proposed Rescission of the Endangerment Finding
In this section, the EPA proposes to rescind the Endangerment
Finding by concluding, based on multiple, independent alternative legal
rationales, that the Agency's unprecedented foray into regulating GHG
emissions from new motor vehicles and engines is inconsistent with the
best reading of CAA section 202(a). Under any proposed alternative, the
EPA would lack authority to retain existing GHG emission standards for
new motor vehicles and engines and proceed to repeal the relevant
provisions of Title 40 of the CFR as proposed in section VI of this
preamble.
Section IV.A of this preamble describes our primary proposal to
rescind the Endangerment Finding by concluding that CAA section 202(a)
does not authorize the EPA to prescribe standards for GHG emissions
based on global climate change concerns or to issue standalone findings
that do not apply the statutory standard for regulation as a cohesive
whole. If finalized, this proposal would require rescinding the
Endangerment Finding and resulting regulations because we lacked
statutory authority to issue them in the first instance. We begin by
proposing the best reading of CAA section 202(a) and related
provisions, as informed by the Supreme Court's decisions in Loper
Bright and UARG. Next, we propose that the Nation's response to global
climate change concerns generally, and specifically whether that
response should include regulating GHG emissions from new motor
vehicles and engines, is an
[[Page 36299]]
economically and politically significant issue that triggers the major
questions doctrine under UARG and West Virginia, and that Congress did
not clearly authorize the EPA to decide it by empowering the
Administrator to ``prescribe . . . standards'' under CAA section
202(a). Throughout this section, we propose that the Endangerment
Finding relied on various forms of Chevron deference \42\ to depart
from the best reading of the statute and exceeded the EPA's authority
in several fundamental respects, any one of which would independently
require rescission to conform to the best reading of the law.
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\42\ Chevron U.S.A., Inc. v. NRDC, Inc., 467 U.S. 837 (1984),
overruled by Loper Bright, 603 U.S. 369; see 74 FR 66501, 66502,
66544 (asserting discretion based on statutory ambiguity, including
that created by silence); 74 FR 66528, 66542, 66543 (asserting
discretion based on statutory ambiguity).
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Section IV.B of this preamble describes the EPA's alternative
proposal that regardless of whether CAA section 202(a) authorizes
regulating GHG emissions based on global climate change concerns, we
would rescind the Endangerment Finding by concluding that the
Administrator analyzed endangerment and contribution in an unreasonable
manner. We begin by recounting the interpretation of CAA section 202(a)
adopted in the Endangerment Finding, which asserted ``procedural
discretion'' to issue standalone findings without prescribing the
standards required by such findings and to sever the analysis of
endangerment from the analysis of contribution. Next, we propose that
the Administrator exercised that discretion unreasonably by adopting an
approach that papered over substantial uncertainties in the scientific
record and failed to draw the required connection between GHG emissions
from a class or classes of new motor vehicles and global climate change
concerns. We further propose that developments since 2009 demonstrate
the uncertainties acknowledged in the Endangerment Finding are more
significant than previously believed, including because many of its
predictive judgments involve ranges of assumptions that largely fail to
satisfy the statutory standard for regulation and because the more
pessimistic assumptions have not been borne out in empirical data and
peer-reviewed studies through 2025. Finally, we propose that the
Administrator would exercise any discretion conferred by CAA section
202(a) differently to ensure a legally and scientifically sound
approach and that, under that approach, the Endangerment Finding and
resulting GHG emission standards must be rescinded.
We seek comment on every aspect of the primary and alternative
proposal, including the key issues on which we specifically request
comment as set out in section VII of this preamble.
A. Primary Rationale for Proposed Rescission
The Endangerment Finding announced an interpretation of CAA section
202(a) that permitted the EPA to prescribe standards in response to
global climate change concerns rather than local or regional exposures,
granted ``procedural discretion'' to issue standalone findings without
considering regulatory response, and severed the finding of
endangerment from the finding of contribution to that endangerment. At
the time, we assumed that statutory silence granted discretion to
construe the scope of our authority and asserted or implied that the
Supreme Court's decision in Massachusetts required us to read the
statute as authorizing the regulation of GHG emissions in response to
global climate change concerns.
In important respects, the Endangerment Finding and the Supreme
Court's decision in Massachusetts straddled a transitional period
regarding the standards for statutory interpretation and understandings
of agency authority. The breadth of agency discretion, and the question
whether Congress reserves major policy questions for itself, were
sharply disputed. Judicial decisions in the intervening fifteen years
have significantly clarified the law in both respects. In Loper Bright,
the Supreme Court expressly overturned the doctrine of deference to
agency statutory interpretation, ruling that statutes ``have a single,
best meaning'' that is informed, but not dictated, by Executive Branch
practice. 603 U.S. at 400-01. And in West Virginia, the Supreme Court
built upon its decisions in UARG and Brown & Williamson, among others,
by confirming that an agency must have more than ``a colorable textual
basis'' to claim authority to decide major questions of policy that
Congress would generally reserve for itself in the first instance. 597
U.S. at 723.
In this subsection, we propose that the best reading of CAA section
202(a), as informed by Loper Bright and principles of statutory
interpretation, does not authorize the EPA to assert jurisdiction over
GHG emissions based on global climate change concerns in a standalone
endangerment finding. Regardless whether GHGs are properly considered
``agents of air pollution'' under the general, Act-wide definition of
``air pollutant'' at CAA section 302(g), the EPA cannot regulate under
CAA section 202(a) unless the emissions of the air pollutant by a class
or classes of new motor vehicles ``cause, or contribute to, air
pollution which may reasonably be anticipated to endanger public health
or welfare.'' Because the text, structure, and history of CAA section
202(a) and related provisions demonstrate that this language targets
air pollution that threatens public health or welfare through local or
regional exposure, ``air pollution'' defined as six ``well-mixed'' GHGs
raising global climate change concerns that adversely impact a subset
of regions globally cannot satisfy this standard. We further propose
that this reading is independently confirmed and strengthened by the
major questions doctrine. Specifically, we propose that the major
questions doctrine applies and precludes the EPA from asserting
authority to regulate in response to global climate change concerns
under CAA section 202(a). At a minimum, Congress did not clearly
authorize the EPA to decide the Nation's response to global climate
change concerns by empowering the Agency to ``prescribe . . .
standards'' for certain air pollutants emitted by new motor vehicles
and engines. On these bases, and on account of the additional
procedural and analytical errors set out below, we propose that the
Endangerment Finding exceeded the EPA's authority and must be
rescinded.
1. Best Reading of CAA Section 202(a)
Congress originally enacted the language of CAA section 202(a) in
the Motor Vehicle Pollution Control Act of 1965 and retained it, with
minor revisions, in the 1970 CAA and all subsequent statutory
amendments. The key language in CAA section 202(a)(1) provides:
The Administrator shall by regulation prescribe (and from time
to time revise) in accordance with the provisions of this section,
standards applicable to the emission of any air pollutant from any
class or classes of new motor vehicles or new motor vehicle engines,
which in his judgment cause, or contribute to, air pollution which
may reasonably be anticipated to endanger public health or
welfare.\43\
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\43\ 42 U.S.C. 7521(a)(1).
Since 1977, CAA section 302(g) has defined the term ``air
pollutant'' throughout the statute as ``any air pollution agent or
combination of such agents . . . which is emitted into or otherwise
enters the ambient air.'' \44\
[[Page 36300]]
CAA section 302(h) also provides that any reference to ``effects on
welfare includes, but is not limited to, effects on'' the environment,
property, transportation hazards, and ``on economic values and on
personal comfort and well-being.'' \45\
---------------------------------------------------------------------------
\44\ 42 U.S.C. 7602(g). Notably, the statute does not separately
define ``air pollution.''
\45\ 42 U.S.C. 7602(h).
---------------------------------------------------------------------------
The EPA proposes that this statutory language is best read as
authorizing the Agency to identify and regulate, as an integral part of
a rulemaking prescribing emissions standards, air pollutants that cause
or contribute to air pollution that itself endangers public health and
welfare through local or regional exposures. This proposed
interpretation is consistent with the text and structure of the
statute, our decades-long implementation of the statute prior to 2009,
and background principles of statutory interpretation, including
default rules for proximate cause. This proposed interpretation is also
consistent with the Supreme Court's decision in Massachusetts, which
addressed distinct issues and must, as a matter of stare decisis, be
read in harmony with the Supreme Court's subsequent decisions bearing
on the EPA's authority and statutory interpretation in UARG, West
Virginia, and Loper Bright.\46\
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\46\ See Hohn v. United States, 524 U.S. 236, 252-53 (1998)
(Supreme Court decisions ``remain binding precedent until [the
Supreme Court] see[s] fit to reconsider them, regardless of whether
subsequent cases have raised doubts about their continuing
vitality.''); Rodriguez de Quijas v. Shearson/Am. Exp., Inc., 490
U.S. 477, 484 (1989) (similar).
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Dangerous Air Pollution. The EPA proposes that CAA section 202(a)
is best read as authorizing the Agency to regulate air pollutant
emissions that cause or contribute to air pollution that endangers
public health or welfare through local or regional exposure. For the
purposes of this proposed action, we use the phrase local or regional
exposure to distinguish air pollution that impacts public health and
welfare by its presence in the ambient air from ``air pollution''
consisting of six ``well-mixed'' GHGs that, as conceptualized in the
Endangerment Finding, impacts public health and welfare only indirectly
and not by its mere presence in the ambient air. As discussed below,
this proposal would effectively return the EPA to its interpretation of
CAA section 202(a) prior to 2009.
We propose that the terms ``air pollutant'' and ``air pollution''
as used in CAA section 202(a)(1) should be construed in accordance with
the specific air pollutants identified for other purposes in the
remainder of CAA section 202. Each of these listed air pollutants share
the common quality of causing or contributing to air pollution that
adversely impacts public health or welfare through local or regional
exposure to the air pollution itself. CAA section 202 specifically
addresses hydrocarbons (HCs), carbon monoxide (CO), oxides of nitrogen
(NOX), and particulate matter (PM), all of which harm health
and the environment through exposure (e.g., inhalation and dermal
contact) or by causing or contributing to air pollution that harms
health and the environment through exposure (e.g., smog and acid
rain).\47\ That pattern holds for the criteria pollutants identified in
the CAA--CO, lead, ground-level ozone (O3), nitrogen dioxide
(NO2), PM, and sulfur dioxide (SO2)--as well as
the initial list of hazardous air pollutants in CAA section
112(b)(1).\48\ We find it significant that in subjecting a number of
air pollutants emitted by new motor vehicles and engines to regulation
under CAA section 202, Congress did not include substances that are
potentially indirectly harmful to public health or welfare based on
elevated global concentrations in the upper atmosphere. That
conspicuous omission supports the conclusion that the air pollutants
subject to regulation under CAA section 202(a) are those that cause or
contribute to air pollution which itself endangers public health or
welfare through local or regional exposure.\49\
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\47\ See, e.g., 42 U.S.C. 7521(a)(3)(A)(i), (b), (g), (h), (j),
(k).
\48\ 42 U.S.C. 7412(b)(1).
\49\ As discussed in section IV.A.2 of this preamble, the only
references to GHGs in the CAA are in non-regulatory contexts in
which Congress authorized funding for various forms of research and
grant programs. The choice to limit such references to non-
regulatory solutions further supports the conclusion that the CAA
section 202(a) regulatory authority for responding to endangerment
does not encompass GHG emissions on the basis of global climate
change concerns.
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Put another way, we propose that the air pollutants identified in
CAA section 202 and throughout relevant provisions of the CAA are those
that cause or contribute to air pollution for which the air pollution
itself, through local or regional exposure to humans and the
environment, endangers public health or welfare.\50\ For certain
regulated air pollutants, the air pollutants are themselves the
dangerous air pollution, i.e., the air pollutants are the air pollution
with adverse health and welfare impacts. An example is CO, which can be
harmful, and even fatal, to humans at sufficient localized
concentrations.\51\ For other regulated air pollutants, the air
pollutants contribute to dangerous air pollution by interacting with
other airborne chemicals or environmental factors such as sunlight to
create the dangerous air pollution, i.e., the air pollutants are
ingredients that create the dangerous air pollution in combination. An
example is acid rain, in which air pollutants such as SO2
interact locally and regionally with additional airborne chemicals to
form acidic precipitation.\52\
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\50\ For example, unlike other regulated air pollutants,
``CO2 is odorless, does not affect visibility and has no
toxicological effects at ambient levels,'' Additionally, the
Permissible Exposure Limit established by the U.S. Occupational
Safety and Health Administration or which diminished performance on
cognitive tasks are ``far larger than any plausible ambient outdoor
value through the end of the 22nd century.''Add 2025 CWG Draft
Report at 2.
\51\ U.S. Environmental Protection Agency. (Last updated Apr.
11, 2025). Carbon Monoxide's Impact on Indoor Air Quality: https://www.epa.gov/indoor-air-quality-iaq/carbon-monoxides-impact-indoor-air-quality.
\52\ U.S. Environmental Protection Agency. (Last updated Mar. 4,
2025). What is Acid Rain?: https://www.epa.gov/acidrain/what-acid-rain.
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The definition of ``air pollutant'' in CAA section 302(g) and the
meaning of the undefined terms pollutant, pollution, and air pollution
support this reading. As a matter of ordinary language, a pollutant is
``[a] poisonous or noxious substance that contaminates the
environment,'' and pollution is ``[t]he harmful addition of a substance
or thing into an environment.'' \53\ Definitions of air pollution
similarly emphasize the emission of ``[c]ontaminants into the
atmosphere.'' \54\ The central concept is the addition of a
contaminant, something, that ``make[s] impure or unclean by contact or
mixture.'' \55\ CAA section 302(g) is consistent with these
definitions, adding only that an ``air pollutant'' is any ``air
pollution agent or combination of such agents'' that ``is emitted into
or otherwise enters the ambient air.'' \56\ Read together with CAA
section 202(a)--as the Supreme Court held we must in UARG--the
underlying concept of dangerousness and contamination reinforces the
conclusion that air pollution which endangers public health or welfare
is air pollution (caused or contributed to by air pollutants) that
itself endangers public health or welfare through local or regional
exposures.
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\53\ Black's Law Dictionary 1403 (11th ed. 2019).
\54\ Id.
\55\ Am. Heritage Dictionary (5th ed. 2022).
\56\ 42 U.S.C. 7602(g).
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The ``air pollution'' addressed in the Endangerment Finding is
different in kind. In that decision, the Administrator defined the
relevant ``air pollutants'' as six ``well-mixed GHGs'' and the relevant
``air pollution'' as ``the combined mix of'' these GHGs ``which
together,
[[Page 36301]]
constitute the root cause of human-induced climate change and the
resulting impacts on public health and welfare.'' 74 FR 66516. In
contrast to the air pollution addressed expressly in CAA section 202
and elsewhere in the statute, GHGs do not endanger public health or
welfare through local or regional exposure. Rather, the Endangerment
Finding asserted that GHG ``air pollution'' would lead to increases in
global temperature and change to ocean pH that, in turn, would lead to
environmental phenomena, in combination with an open-ended universe of
additional factors, which would potentially have adverse public health
and welfare impacts of varying severity in certain regions. Regulating
GHG emissions based on global climate change concerns requires reading
an additional instance of ``cause, or contribute'' into the statute,
such that CAA section 202(a) encompasses the `emission of air
pollutants that cause, or contribute to, dangerous air pollution that
causes, or contributes to, endangerment of public health or welfare.'
This proposed interpretation is also supported by the best reading
of the terms ``cause'' and ``contribute.'' In enacting and amending CAA
section 202(a), Congress legislated against background legal
principles, including principles of causation and proximate cause.\57\
These ``default rules'' are ``presumed to have [been] incorporated,
absent an indication to the contrary in the statute itself,'' \58\ and
nothing in the text of CAA section 202(a) indicates that Congress
intended to depart from ordinary legal meaning. As a general matter,
there is a point at which harm no longer has a sufficiently close
connection to the relevant conduct to reasonably draw a causal link. We
propose that emissions from new motor vehicles and new motor vehicle
engines in the United States do not have a sufficiently close
connection to the adverse impacts identified in the Endangerment
Finding to fit within the legal meaning of ``cause'' or ``contribute.''
The Endangerment Finding largely avoided addressing this problem by
severing the question whether GHG emissions from new motor vehicle
engines contribute to GHG concentrations in the atmosphere from the
question whether GHG concentrations in the atmosphere endanger public
health and welfare. As discussed in further detail in section IV.A.1 of
this preamble, we propose that there is no basis in the statute for
severing the inquiry in that way. Nevertheless, even with respect to
endangerment and contribution in isolation, we propose that global
climate change concerns involve analyzing causal relationships that are
too uncertain, too remote, and too confounded by intervening and
confounding factors to fit within the terms ``cause'' and
``contribute'' as used in CAA section 202(a). This understanding
follows from the position discussed above that CAA section 202(a) and
the statute more generally were designed to regulate air pollution with
harmful impacts from local and regional exposure that are analyzable by
ordinary causation standards.
---------------------------------------------------------------------------
\57\ See, e.g., Bank of Am. Corp. v. City of Miami, 581 U.S.
189, 201 (2017); Lexmark Int'l, Inc. v. Static Control Components,
Inc., 572 U.S. 118, 132 (2014); Univ. of Tex. Sw. Med. Ctr. v.
Nassar, 570 U.S. 338, 347 (2013); City of Oakland v. Wells Fargo &
Co., 14 F.4th 1030 (9th Cir. 2021) (en banc).
\58\ Nassar, 570 U.S. at 347.
---------------------------------------------------------------------------
In proposing this interpretation, we note that a limiting
construction is necessary to avoid absurd results and potential
conflict with the nondelegation doctrine. Because Congress cannot
delegate legislative powers to the Executive Branch, statutes granting
an agency regulatory authority must provide an intelligible principle
to guide its exercise.\59\ Our authority under CAA section 202(a) to
``prescribe . . . standards'' for air pollutant emissions by a class or
classes of new motor vehicles and engines is limited by the requirement
that the Administrator find such air pollutants cause or contribute to
air pollution that may reasonably be anticipated to endanger public
health and welfare. We propose that the best reading of the statute
circumscribes this authority to air pollution that itself causes or
contributes to endangerment of public health or welfare. Under the
interpretation adopted in the Endangerment Finding, however, our
authority under CAA section 202(a) would have no readily discernible
limiting principle, particularly in combination with the authority
asserted to sever the analysis of endangerment and causation or
contribution. Following the logic of the Endangerment Finding, any
``air pollutant'' emitted at more than de minimis volumes would trigger
our authority, and the statutory obligation, to prescribe standards so
long as the emission contributes to ``air pollution'' that, in turn,
potentially contributes to phenomena with predicted adverse impacts on
public health and welfare broadly defined. As discussed further below,
under this logic, the release of water vapor (H2O) would
meet the standard for regulation because water can be said to result in
significant harms and because motor vehicles and engines can be said to
``contribute'' to that harm by emitting non-de minimis quantities of
water vapor into the upper atmosphere. The EPA would have the
authority, and statutory duty, to prescribe standards for water vapor
emissions because water vapor is a recognized GHG emitted by motor
vehicles and engines as well as the vast majority of other mobile and
stationary sources. Because that reading effectively converts CAA
section 202(a)(1) into a roaming license to ``prescribe . . .
standards,'' we believe the reading proposed herein is more faithful to
the governing principles of statutory interpretation.
---------------------------------------------------------------------------
\59\ See, e.g., Gundy v. United States, 588 U.S. 128 (2019).
---------------------------------------------------------------------------
We further emphasize that this proposed interpretation would
effectively return the EPA to its longstanding practice prior to 2009
of applying CAA section 202(a) and related statutory endangerment
provisions to air pollution that adversely impacts public health and
welfare through local or regional exposure. As noted above, we
historically utilized this authority to prescribe standards for
pollutants identified in the CAA itself, including NOX, PM,
HC, and CO. The distinction between air pollution that harms public
health and welfare through local and regional exposure and global ``air
pollution'' consisting of GHG concentrations without any such direct
impacts has also played a role in our evaluation of waiver requests
under CAA section 209.\60\ Even in the Endangerment Finding, the
Administrator recognized that we had previously applied CAA section
202(a) to ``a more typical local or regional air pollution problem.''
74 FR 66538 (emphasis added). We propose that in adopting a novel
analytical approach in the Endangerment Finding, the EPA failed
adequately to address its prior practice and improperly relied on the
Supreme Court's decision in Massachusetts for the proposition that CAA
section 202(a) authorizes emission standards in response to air
pollution raising global climate change concerns. As discussed below,
Massachusetts did not construe the scope of the EPA's authority to
regulate under CAA section
[[Page 36302]]
202(a), and the Court has since made clear in UARG and West Virginia
that our authority to regulate air pollutants that fit within the Act-
wide definition turns on the particular statutory provision that
confers authority to regulate.
---------------------------------------------------------------------------
\60\ See, e.g., ``California State Motor Vehicle Pollution
Control Standards; Notice of Decision Denying a Waiver of Clean Air
Act Preemption for California's 2009 and Subsequent Model Year
Greenhouse Gas Emission Standards for New Motor Vehicles,'' 73 FR
12156, 12161 (Mar. 6, 2008) (denying California's waiver request for
GHG emission standards on the ground that ``the different, and
global, nature of the pollution at issue'' requires a different
conceptual approach).
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In Massachusetts, the Supreme Court rejected the argument that GHGs
are not ``air pollutants'' under the Act-wide definition, reasoning
that CAA section 302(g)'s use of the word ``any'' in connection with
``air pollutant agent or combination of such agents, including any
physical [or] chemical . . . substance'' was sufficiently broad to
encapsulate the combination of GHGs at issue. 549 U.S. at 530. On this
basis, the Court stated that the EPA ``has the statutory authority to
regulate the emission of such gases from new motor vehicles.'' Id. at
532. The Court did not, however, decide whether including GHGs within
the definition of ``air pollutant'' meant that we must find that GHGs
meet the statutory standard for regulation under CAA section 202(a)
because they cause or contribute to air pollution which endangers the
public health or welfare. Rather the Court concluded its opinion by
clarifying that it ``need not and do[es] not reach the question whether
on remand EPA must make an endangerment finding.'' Id. at 534.
Consistent with Massachusetts, we propose to interpret the CAA as
setting out a broad, threshold definition of ``air pollutant'' on an
Act-wide basis that must be interpreted in the context of each
applicable, particular provision granting regulatory authority in order
to determine whether that provision authorizes the EPA to regulate an
air pollutant under that particular authority. For purposes of CAA
section 202(a), that means that even if GHGs are ``air pollutant[s]''
as defined on an Act-wide basis, they must meet the statutory standard
for regulating emissions from new motor vehicles and engines before we
may invoke our regulatory authority. Put simply, regardless whether
GHGs are ``air pollutants'' as defined in CAA section 302(g), they must
still satisfy the same standard as any other ``air pollutant'' by
causing or contributing to air pollution which may reasonably be
anticipated to endanger public health or welfare.
This understanding is confirmed by UARG, in which the Supreme Court
distinguished between ``the Act-wide definition'' of air pollutant and
the application of that definition to the Act's regulatory provisions.
573 U.S. at 320. The Court specifically addressed the holding in
Massachusetts, adopting the argument that ``while Massachusetts
rejected EPA's categorical contention that [GHGs] could not be air
pollutants for any purposes of the Act, it did not embrace EPA's [then]
current, equally categorical position that [GHGs] must be air
pollutants for all purposes regardless of the statutory context.'' Id.
(cleaned up).
In sum, we propose that CAA section 202(a) does not provide
authority to regulate GHGs based on global climate change concerns
because that provision authorizes regulating only air pollutants that
``cause, or contribute to, air pollution which may reasonably be
anticipated to endanger public health or welfare.'' The EPA must
``ground its reasons for action or inaction in the statute,''
Massachusetts, 549 U.S. at 535, and ``possess[es] only the authority
that Congress has provided,'' NFIB v. DOL, 595 U.S. 109, 117 (2022). In
proposing this interpretation, we note that our actions must be
consistent with ``the single, best meaning'' of the statute and cannot
expand our authority in response to pressing concerns based on
statutory silence or ambiguity. Loper Bright, 603 U.S. at 400, 411. We
seek comment on this proposed interpretation, including the rationales
articulated above and any further rationales that commenters believe
support, or detract from, this interpretation.
Findings and Standards. The EPA further proposes that CAA section
202(a) requires issuing emission standards together with the findings
necessary to invoke our regulatory authority, rather than severing the
regulatory action into separate endangerment and standards-setting
proceedings. The statute begins by providing that the Administrator
``shall prescribe . . . standards applicable to the emission of any air
pollutant from any class or classes of new motor vehicles or new motor
vehicle engines,'' and follows this requirement by describing the scope
of the duty to regulate air pollutant emissions ``which, in his
judgment cause, or contribute to, air pollution which may reasonably be
anticipated to endanger public health or welfare.'' We propose that the
best reading of the statute requires the Administrator, when
prescribing any emission standard for new motor vehicles or engines, to
find that the air pollutant or air pollutants emitted by the class or
classes of new motor vehicles or engines subject to the standard cause
or contribute to air pollution that may reasonably be anticipated to
endanger public health or welfare.
The Endangerment Finding severed this statutory language by finding
endangerment and contribution in the abstract for all potential CAA
section 202(a) sources with respect to GHGs. In so doing, the
Administrator vastly increased the Agency's authority by removing the
restrictions Congress placed on the issuance of emission standards. As
a result of this new conception of authority, the EPA may issue a
single endangerment finding in the abstract with respect to emissions
from all sources potentially subject to CAA section 202(a) (and their
existing-source counterparts) without addressing the danger posed by
any particular source category or the causal role of that particular
source category in any identified danger. The EPA has since relied on
the Endangerment Finding to prescribe emission standards for various
classes of new motor vehicles and engines, as well as a variety of
other sources under distinct statutory authorities, without making the
requisite findings or assessment of factors necessary to regulate the
sources in question.\61\ We propose that Congress enacted CAA section
202(a) as an integrated regulatory provision for a reason, and that
giving effect to the language of the statute requires the issuance of
emission standards only when the Administrator has made an integrated
finding of both endangerment and cause or contribution. Put another
way, we propose that it is impermissible for the Administrator to make
an endangerment finding without prescribing the emission standards
required in response to such a finding, and conversely, that it is
impermissible to prescribe emission standards without making the
source- and air-pollutant specific findings required by the statute.
---------------------------------------------------------------------------
\61\ See sections II.C, VI.B, and VI.C of this preamble for a
summary of the EPA's rulemaking activities in response to the
Endangerment Finding.
---------------------------------------------------------------------------
This proposed interpretation is consistent with the EPA's
implementation of CAA section 202(a) and similar provisions of the CAA
prior to 2009. In the Endangerment Finding, the Administrator
acknowledged that ``typically endangerment and cause or contribute
findings have been proposed concurrently with proposed standards under
various sections of the CAA, including CAA section 201(a).'' 74 FR
66501. We propose that our historical practice under CAA section 202(a)
reflects the better reading of the statute and is entitled to greater
weight. As the Supreme Court recently explained, such weight is
``especially warranted when an Executive Branch interpretation was
issued roughly contemporaneously with enactment of the statute and
remained consistent over time.'' Loper Bright, 603 U.S. at 386.
[[Page 36303]]
In departing from the EPA's historical practice in the Endangerment
Finding, the Administrator reasoned that ``[t]he text of CAA section
202(a) is silent on this issue'' and ``invoked the procedural
discretion that is provided by CAA section 202(a)'s lack of specific
direction.'' 74 FR 66501. We propose that CAA section 202(a) is not
silent on the issue because the statute sets out an integrated process
that requires the EPA to prescribe standards when the Administrator
finds certain conditions are met. When Congress intends a multi-step
inquiry in the environmental context, it typically says so expressly.
In the National Ambient Air Quality Standards (NAAQS) program, for
example, the CAA separates our authority to establish and revise the
NAAQS under CAA section 108 and 109 from our duties to implement the
NAAQS by reviewing State Implementation Plans (SIPs) or promulgating
Federal Implementation Plans (FIPs) under CAA section 110 and related
statutory provisions.\62\ A particularly relevant analogy is Clean
Water Act section 303(c)(4), which pairs the Administrator's authority
to ``determin[e] that a revised or new [water quality standard] is
necessary to meet the requirements of this chapter'' with the
requirement that the Administrator ``shall promptly prepare and publish
proposed regulations'' after making such a determination and
``promulgate any revised or new standard . . . not later than ninety
days after he publishes such proposed standards.'' \63\ We further
propose that even if CAA section 202(a) were ambiguous or silent in
this respect, the Supreme Court recently held in no uncertain terms
that ``statutory ambiguity . . . is not a reliable indicator of actual
delegation of discretionary authority to agencies.'' Loper Bright, 603
U.S. at 411.
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\62\ See 42 U.S.C. 7408, 7409, 7410.
\63\ 33 U.S.C. 1313(c)(4), (c)(4)(B). Various provisions of the
Safe Drinking Water Act (SDWA) and Toxic Substances Control Act
(TSCA) similarly articulate multi-step processes for determining
risk and addressing risk through regulation using language that
Congress did not include in CAA section 202.
---------------------------------------------------------------------------
Severing the EPA's standards-setting authority from the findings
that trigger a duty to exercise that authority shaped the analysis in
the Endangerment Finding in a manner that we propose ran counter to the
statute. Recall that the Endangerment Finding first projected adverse
public health and welfare impacts of global climate change and
attributed those adverse impacts to all manmade sources of GHG emission
around the world and then, separately, used data from existing CAA
section 202(a) sources in the United States to find that new motor
vehicles and engines in the United States contributed to global GHG air
pollution. The Administrator treated adaptation (adjustments to the
effect of climate change that lessen impacts) and mitigation
(reductions in emissions and global GHG concentrations unrelated to CAA
section 202(a) regulation) as outside the scope. 74 FR 66512. Moreover,
the Administrator declined to consider cost, asserting that the
Endangerment Finding imposed no regulatory requirements as a standalone
action and relying on the Supreme Court's decision in Whitman v.
American Trucking Association, 531 U.S. 457 (2001), that the EPA cannot
consider cost in setting and revising the NAAQS under CAA section 109.
74 FR 66515. Nor did the Administrator consider potential beneficial
impacts from climate change with respect to whether and which standards
would be appropriate. See 74 FR 66524 (purporting to compare ``risks
and benefits'' only with respect to endangerment).
Severance also shaped all subsequent standards prescribed and
revised in reliance on the Endangerment Finding in a manner we propose
to conclude was unlawful. The EPA asserted in subsequent rulemakings
that there was no need to make particularized findings for the relevant
source category because the Endangerment Finding identified public
health and welfare dangers and contribution for all CAA section 202(a)
source categories. Nor did we consider the impacts of adaptation or
mitigation or consider when prescribing standards whether, in light of
more recent empirical data, the Endangerment Finding's analysis of
endangerment and contribution remained accurate with respect to the
source category at issue. As a result, the decision to sever meant that
the EPA has never meaningfully considered or invited public comment on
the cost, effectiveness, and continued propriety of its GHG regulatory
program.
We propose that these considerations should have been taken into
account when the 2009 Endangerment Finding intentionally triggered a
duty to regulate by invoking our CAA section 202(a) authority. CAA
section 202(a)(2) expressly provides that ``[a]ny regulation prescribed
under paragraph (1) of this subsection . . . shall'' provide adequate
time for ``the development and application of the requisite technology,
giving appropriate consideration to the cost of compliance within such
period.'' \64\ CAA section 202(a)(1) authorizes the Administrator to
``by regulation prescribe'' standards ``in accordance with the
provisions of this section'' and does not separately authorize
standalone findings, meaning any action taken ``under paragraph (1) of
this subsection'' is subject to the considerations in paragraph (2).
That statutory language aside, the Supreme Court explained in Michigan
that ``agency action is lawful only if it rests `on a consideration of
the relevant factors,' '' 576 U.S. at 750 (quoting State Farm, 463 U.S.
at 43), including ``at least some attention to cost,'' id. at 752. We
propose that the Administrator erred in analogizing to the NAAQS
program and the Supreme Court's decision in Whitman to avoid
considering costs in the Endangerment Finding. Unlike CAA section
202(a), the language in CAA section 109(b) makes no reference to cost
or implementation and focuses solely on safety and an adequate margin
to protect public health. Nor does CAA section 109(b) include the lead
time and technical feasibility concepts embedded in CAA section 202(a).
And whereas CAA section 202(a) sets out an integrated authority to
prescribe emission standards when the provision's triggering condition
is satisfied, CAA section 109(b) uses mandatory language requiring the
EPA to establish certain standards, the content and implementation of
which are specified in various provisions throughout Title I of the
Act. We further propose that the Supreme Court's decision in
Massachusetts did not address the question whether the EPA could issue
standalone findings or bar the Administrator from taking cost and
implementation concerns into account when exercising CAA section 202(a)
authority. Rather, Massachusetts must be read together with Michigan,
and the language of CAA section 202(a)(1) must be read in context to
``produc[e] a substantive effect that is compatible with the rest of
the law.'' UARG, 573 U.S. at 321 (quoting United Sav. Ass'n of Tex. v.
Timbers of Inwood Forest Assocs., 484 U.S. 365, 371 (1988)).
---------------------------------------------------------------------------
\64\ 42 U.S.C. 7521(a)(2).
---------------------------------------------------------------------------
Endangerment and Cause or Contribute. The EPA also proposes that
CAA section 202(a) requires the Agency to evaluate whether source
emissions cause or contribution to air pollution and whether that air
pollution poses endangerment in a single causal chain, rather than
considering these issues in isolation by severing the inquiries. The
relevant inquiry is whether ``the emission of any air pollutant from
any class or classes of new motor vehicles or
[[Page 36304]]
new motor vehicle engines,'' in the judgment of the Administrator,
``cause, or contribute to, air pollution which may reasonably be
anticipated to endanger public health or welfare.'' As explained in
this section, the emission must cause or contribute to the danger posed
by the air pollution to a sufficient extent to satisfy the standard for
regulation.
In the Endangerment Finding, the Administrator made two distinct
findings based on two distinct sets of assumptions. In the first, the
Administrator found that the ``air pollution,'' defined as the combined
elevated global concentrations in the upper atmosphere of six ``well-
mixed GHGs,'' CO2, methane, NOX, HFCs, PFCs, and
SF6, endangered public health or welfare by playing a causal
role in global temperature increases and ocean pH changes, which, in
turn, were then asserted to play a causal role in environmental
phenomena with adverse impacts on public health and welfare. 74 FR
66516. In the second, the Administrator found that the ``air
pollutant'' (defined as the combination of same six ``well-mixed
GHGs'') emitted by new motor vehicles and engines contributed to the
``air pollution.'' 74 FR 66536. Nowhere in the Endangerment Finding did
the Administrator consider the extent to which emissions from CAA
section 202(a) sources have a more than de minimis effect on the danger
identified with respect to elevated concentrations of GHGs in the upper
atmosphere--let alone whether emissions from any particular class or
classes of sources that EPA intended to regulate had such an effect.
Upon review, we no longer believe that the approach taken in the
Endangerment Finding was consistent with the language of CAA section
202(a) and the structure of the CAA, which requires making distinct
findings for regulating distinct types of emission sources and
authorizes different regulatory tools when such standards are met. For
example, CAA section 111(b)(1)(A) authorizes the EPA to regulate
emissions from listed categories of stationary sources if the
Administrator determines those sources emit air pollutants that
``significantly contribute'' to dangerous air pollution.\65\ When that
standard is met, CAA section 111(b)(1)(B) requires the EPA to regulate
such emissions from such sources by setting standards of performance
that, among other things, reflect the best system of emission reduction
that has been adequately demonstrated in practice.\66\ The CAA
similarly sets out distinct standards for regulating and distinct modes
of regulation for additional major source categories, including
vehicles in use, aircraft engines, and separately addresses when and
how to respond to international emissions that impact the United
States. The Endangerment Finding effectively attributed the total GHG
emissions coming from all of these various distinct sources within the
United States, as well as from all international sources, to the mobile
sources regulated under CAA section 202(a) without having made the
requisite determinations for any of those sources and without
considering the different regulatory tools Congress authorizes for
those sources as compared to CAA section 202(a) sources. The
Administrator defined the relevant ``air pollution'' as the combination
of six ``well-mixed GHGs'' but found that CAA section 202(a) sources
emitted only four of them: CO2, methane, NOX, and
HFCs. 74 FR 66538. As a result, the ``air pollution'' identified as
endangering public health or welfare included PFCs and SF6,
and the ``air pollution'' used to conclude that CAA section 202(a)
sources satisfy the regulatory standard did not. Contrary to the EPA's
conclusion at the time, 74 FR 66541, that difference is material, as
PFCs and SF6 are asserted to have many times the global
warming potential of CO2.\67\ Severing the endangerment and
cause-or-contribute analysis allowed the Agency to compare apples and
oranges in a manner the statute does not authorize.
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\65\ 42 U.S.C. 7411(b)(1)(A).
\66\ 42 U.S.C. 7411(a)(1), (b)(1)(B). CAA section 111 also
differentiates between new and existing stationary sources in a
listed source category and limits the EPA's role with respect to
existing sources by authorizing only emission guidelines implemented
by the States. 42 U.S.C. 7411(d).
\67\ U.S. Environmental Protection Agency. (Last updated Jan.
16, 2025). Understanding Global Warming Potentials: https://www.epa.gov/ghgemissions/understanding-global-warming-potentials.
---------------------------------------------------------------------------
The Endangerment Finding also did not limit its analysis of
contribution to ``new motor vehicles or new motor vehicle engines'' in
the United States, which are the only sources covered by the EPA's CAA
section 202(a) authority.\68\ Because the Administrator considered all
sources in analyzing the danger posed by elevated concentrations of
GHGs in the upper atmosphere, the endangerment analysis necessarily
included emissions from foreign and domestic vehicles that had been in
use for years or decades and were not ``new.'' Even when analyzing
contribution, the Administrator used emission estimates from ``the
entire fleet of motor vehicles in the United States for a certain
calendar year'' rather than projecting emissions from new motor
vehicles and engines over time. 74 FR 66543. That decision increased
the absolute contribution figure by orders of magnitude, including
because newer vehicles and engines tend to be more efficient and emit
less.\69\ Difficulties in disaggregating emission data from emission
sources, however reasonable, do not license us to read the term ``new''
out of the statutory text.
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\68\ 42 U.S.C. 7521(a)(1) (emphases added).
\69\ For additional discussion of improvements in new motor
vehicles and engines relative to older vehicles and engines, see
section V of this preamble.
---------------------------------------------------------------------------
We are also concerned that severing the endangerment and cause or
contribution findings leads to untenable results and lacks any limiting
principle. To illustrate the problem, the same logic would allow the
EPA to issue emission standards for water vapor (H2O),
another substance emitted by new motor vehicles and engines that is
also considered a powerful GHG. Considered in isolation, H2O
concentrations in the atmosphere can be said to endanger public health
or welfare by resulting in rain that leads to slip-and-fall injuries,
drownings, and damage to crops, livestock, and property, including
through pools, rivers, and floodwater, although water vapor is not
itself harmful and is necessary to sustain life. Also considered in
isolation, CAA section 202(a) sources can be said to ``contribute'' to
elevated H2O concentrations in the atmosphere from all
anthropogenic sources, and these emissions of water vapor would thereby
assertedly ``contribute'' to global climate effects similar to those
attributed to other GHGs. CAA section 202(a) does not contemplate
prescribing emission standards for such an omnipresent, naturally
occurring, and essential component of the ambient air, and stakeholders
have not petitioned for such regulation, because the text requires
analyzing the extent to which emissions contribute to the danger. The
logic of regulating water vapor would appear to be absurd, but it is
the same logic required to regulate GHGs under CAA section 202(a).
We further propose that the decision to sever the analysis of
endangerment from the analysis of contribution, combined with the
decision to sever the Administrator's findings from any standards
prescribed as a result, produced an analysis that is incompatible with
the statute. In the Endangerment Finding, the Administrator concluded
that anything more than a trivial or de minimis
[[Page 36305]]
contribution to elevated global GHG concentrations by CAA section
202(a) sources was sufficient to trigger regulation because the
``unique, global aspects of the climate change problem tend to support
contribution at lower percentage levels of emissions than might
otherwise be considered appropriate when addressing a more typical
local or regional air pollution problem.'' 74 FR 66538. Because the
Endangerment Finding did not consider the standards that the statute
requires when the Administrator makes such a finding, we did not
consider whether emission standards for new motor vehicles would be
futile as a means to address the identified dangers of GHG emissions
from all anthropogenic sources. As discussed in sections IV.A and IV.B
of this preamble, reducing GHG emissions from all vehicles and engines
in the United States to zero would not have a scientifically measurable
impact on GHG emission concentrations or global warming potential (2025
CWG Draft Report at 130).\70\ It was foreseeable at the time that
issuing the Endangerment Finding would trigger a duty to regulate, and
that extraordinarily stringent measures would be necessary under all of
the EPA's separate statutory authorities, and not just CAA section
202(a), to have any potentially measurable impact on the identified
harm. Additionally, the EPA did not consider ``carbon leakage,'' which
``refers to the situation that may occur if, for reasons of costs
related to climate policies, businesses were to transfer production to
other countries with laxer emission constraints . . . [and] could lead
to an increase in their total emissions.'' \71\ Foreign governments
have recognized that carbon leakage can mitigate or even lead to an
increase in total emissions which would significantly impact the
claimed benefits of the regulatory actions.\72\ Accordingly, we propose
that refusing to consider these foreseeable consequences was
inconsistent with the statutory scheme and, as explained further below,
arbitrary and capricious and an abuse of discretion.
---------------------------------------------------------------------------
\70\ See Lomborg, B. (2016). Impact of Current Climate
Proposals. Global Policy, 7(1) 109-118: https://doi.org/10.1111/1758-5899.12295.
\71\ Carbon leakage. (2019). European Commission: https://climate.ec.europa.eu/eu-action/eu-emissions-trading-system-eu-ets/free-allocation/carbon-leakage_en.
\72\ See, e.g., id.
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Finally, we propose that the Administrator did not adequately
consider the meaning in context of the statutory term ``endanger'' and
failed to identify with sufficient rigor the purported danger linked to
GHG emissions from new motor vehicles and engines. We propose that
``endanger'' as used in CAA section 202(a) cannot mean merely any
predicted negative impact to any public health or welfare value, as
that interpretation would render the constraint placed on the EPA's
authority to prescribe standards essentially meaningless, thereby
violating ordinary principles of statutory interpretation and raising
constitutional nondelegation concerns. We further propose that severing
the endangerment and contribution inquiries improperly allowed the
Administrator to avoid this concern by concluding that new motor
vehicle and engine emissions included more than de minimis GHG
emissions, even if those emissions did not themselves contribute to a
danger in any meaningful sense. See 74 FR 66543 (asserting that
``contributors must do their part even if their contributions to the
global problem, measured in terms of percentage, are smaller than
typically encountered''). We therefore seek comment on whether this
aspect of EPA's interpretation and application of the statutory
provision in 2009 was defective and whether, either on its own or in
combination with the other bases and rationales presented here, this
issue provides additional grounds for rescinding the Endangerment
Finding and resulting GHG emission standards for new motor vehicles and
engines.
2. Lack of Clear Congressional Authorization
The EPA further proposes that, at a minimum and in addition to the
interpretation set out above, we lack the ``clear congressional
authorization'' required under the major questions doctrine to decide
the Nation's response to global climate change concerns. West Virginia,
597 U.S. at 723 (quoting UARG, 573 U.S. at 324). In this subsection, we
propose that the major questions doctrine applies to the Endangerment
Finding because the global climate change concerns addressed in that
action, and the mandatory duty to regulate triggered by that action,
present a major question of undeniable political and economic
significance. Next, we propose that Congress did not clearly authorize
the EPA to decide this question when it empowered the Administrator to
``prescribe . . . standards'' for new motor vehicle and engine
emissions under CAA section 202(a). On that basis, we propose to
conclude that the Endangerment Finding and resulting GHG emission
standards exceeded our statutory authority and should be rescinded.
That conclusion follows from the Supreme Court's decisions in UARG and
West Virginia and is consistent with Massachusetts, which held that
GHGs fell within the definition of ``air pollutant'' but did not
interpret the scope of our authority to regulate air pollutants that
cause, or contribute to, air pollution which may reasonably be
anticipated to endanger public health or welfare.
Applicability of the Major Questions Doctrine. In recent decisions
construing the scope of the EPA's statutory authority to regulate GHGs,
the Supreme Court has emphasized that the `` `history and breadth of
the authority' '' asserted by an agency and ``the `economic and
political significance' of that assertion'' provide ```a reason to
hesitate before concluding that Congress' meant to confer such
authority.'' West Virginia, 597 U.S. at 721 (quoting Brown &
Williamson, 529 U.S. at 159-60); accord UARG, 573 U.S. at 324. Whether
viewed as an ordinary tool of statutory interpretation that looks to
the structure of the regulatory scheme \73\ or a clear statement rule
that implements nondelegation and separation of power principles,\74\
the major questions doctrine requires us to identify ``more than a
merely plausible textual basis'' when asserting authority to decide a
significant policy issue on Congress' behalf. Id. at 723.
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\73\ Biden v. Nebraska, 600 U.S. 477, 507-21 (2023) (Barrett,
J., concurring).
\74\ West Virginia, 597 U.S. at 735-51 (Gorsuch, J.,
concurring).
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In UARG, the Supreme Court applied the major questions doctrine to
reject our attempt to regulate GHG emissions from stationary sources
subject to the CAA's prevention of significant deterioration (PSD) and
Title V permitting requirements based on the global climate change
concerns identified in the Endangerment Finding. 573 U.S. at 311-
13.\75\ The Court held that the EPA had ``exceeded its statutory
authority when it interpreted the Clean Air Act to require PSD and
Title V permitting for stationary sources based on their greenhouse gas
emissions'' and ``may not treat greenhouse gases as a pollutant'' in
the PSD and Title V contexts. Id. at 333. In reaching this conclusion,
the Court found that our interpretation of the statute and related
``tailoring rule'' that exempted many sources to address workability
concerns was ``unreasonable because it would bring about an enormous
and transformative expansion in EPA's regulatory authority without
clear congressional authorization.'' Id. at 324. Citing earlier major
questions doctrine
[[Page 36306]]
precedents, the Court noted that ``a measure of skepticism'' is
required when ``an agency claims to discover in a long-extant statute
an unheralded power to regulate `a significant portion of the American
economy,' '' id. (quoting Brown & Williamson, 529 U.S. at 159), and
that ``[w]e expect Congress to speak clearly if it wishes to assign to
an agency decisions of vast `economic and political significance,' ''
id. (quoting Brown & Williamson, 529 U.S. at 160).
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\75\ See 42 U.S.C. 7470-92, 7661 et seq.
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In West Virginia, the Supreme Court again applied the major
questions doctrine to reject our attempt to shift the power grid away
from using fossil fuels through GHG emission guidelines for existing
power plants under CAA section 111(d). 597 U.S. at 711-15.\76\ The
Court noted that when interpreting a grant of regulatory authority, the
inquiry includes the question ``whether Congress in fact meant to
confer the power the agency has asserted.'' Id. at 721. The Court
explained that the major questions doctrine applies when ``the `history
and breadth of the authority that [the agency] has asserted,' and the
`economic and political significance' of that assertion, provide `a
reason to hesitate before concluding that Congress' meant to confer
such authority.'' Id. (quoting Brown & Williamson, 529 U.S. at 159-60).
In such cases, ``both separation of powers principles and a practical
understanding of legislative intent make us `reluctant to read into
ambiguous statutory text' the delegation claimed to be lurking there,''
and ``[t]he agency instead must point to `clear congressional
authorization' for the power it claims.'' Id. at 723 (quoting UARG, 573
U.S. at 324). Applying that standard, the Court held that our statutory
authority to establish emission limits under CAA section 111(a)(1) and
(d) ``is not close to the sort of clear authorization required by our
precedents.'' Id. at 732.
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\76\ See 42 U.S.C. 7411(d). The EPA had also issued GHG
performance standards for new and modified fossil fuel-fired power
plants under CAA section 111(b) that triggered the Agency's
authority to issue guidelines for existing sources under CAA section
111(d). The new source standards were not before the Supreme Court
in West Virginia.
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We propose that the Endangerment Finding implicates the major
questions doctrine for the same reasons the Supreme Court applied it in
UARG and West Virginia. By asserting jurisdiction to regulate in
response to global climate change concerns, the EPA `` `claim[ed] to
discover in a long-extant statute an unheralded power' representing a
`transformative expansion in [its] regulatory authority.' '' West
Virginia, 597 U.S. at 724 (quoting UARG, 573 U.S. at 324). We note that
the regulatory actions reviewed in UARG and West Virginia were
predicated in part on the Endangerment Finding and propose that the PSD
and Title V rules in UARG and existing source emission guidelines in
West Virginia are similar in scope, approach, and economic impact as
the GHG emission standards for new motor vehicles and engines
promulgated to fulfill the mandatory duty triggered by the Endangerment
Finding. As a consequence of the novel approach taken in the
Endangerment Finding to endangerment and contribution, our GHG emission
standards mandate an increased and faster shift from gasoline-fueled
vehicles to electric vehicles on the theory that a substantial
reduction in GHG emissions is necessary to address global climate
change concerns.\77\ We propose that mandating a shift in the national
vehicle fleet from one type of vehicle to another is indistinguishable
from the emission guidelines at issue in West Virginia, which were
calculated to force a shift from one means of electricity generation to
another.
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\77\ 89 FR 27842, 27844.
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We further propose it is `` `highly unlikely that Congress would
leave' to `agency discretion' the decision'' of how much gasoline
should be used by vehicles and engines in the United States. West
Virginia, 597 U.S. at 729 (quoting MCI Telecomms. Corp. v. AT&T Co.,
512 U.S. 218, 231 (1994)). As the Supreme Court noted with respect to
coal-based electricity generation, such a policy decision involves
``basic and consequential tradeoffs,'' and ``Congress certainly has not
conferred a like authority upon EPA anywhere else in the Clean Air
Act.'' Id. Until the Endangerment Finding, moreover, we had never
invoked CAA section 202(a) or any other CAA authority to regulate in
response to global climate change concerns, whether through a fuel-
shifting strategy or any other means. That history is telling because
although CAA section 202(a) has existed in substantially similar form
since 1967, ``the EPA had never regulated in that manner, despite
having issued many prior rules governing'' vehicle and engine
emissions. Id.
When Congress has addressed GHGs individually or collectively, it
has not granted the EPA broad regulatory authority comparable to our
authority to ``prescribe . . . standards'' under CAA section 202(a).
With respect to HFCs, Congress enacted a comprehensive phaseout scheme
in the 2020 American Innovation and Manufacturing (AIM) Act, which
includes detailed instructions, timelines, and requirements for
implementation and allows some uses to continue under certain
conditions.\78\ With respect to CO2, Congress opted for a
carrot rather than a stick by authorizing a tax credit to incentivize
underground sequestration that mitigates emissions.\79\ With respect to
methane, Congress amended the CAA in 2021 through the Inflation
Reduction Act of 2022 (IRA) to require us to establish a waste
emissions charge for certain sources structured to incentivize
emissions reductions over time.\80\ When addressing GHGs more
generally, Congress has used non-regulatory tools that incentivize,
rather than mandate, changes in private ordering, including through
additional funding provisions in the IRA.\81\ We propose that multiple
instances of recent legislation addressing GHGs individually and
through distinct regulatory approaches suggests that Congress views
such policy decisions as economically and politically significant and
not adequately addressed by general statutory authorities enacted in
response to different problems.
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\78\ Public Law 116-260, Div. S, codified at 42 U.S.C. 7675 et
seq.
\79\ 26 U.S.C. 45Q. In 2020, Congress also instructed us to
recommend improvements to SDWA permitting procedures for injection
wells used in carbon sequestration and appropriated additional
fundings for the ``Class VI'' permitting process. Public Law 116-
260, Div. G, Title II.
\80\ Public Law 117-169, codified at 42 U.S.C. 7436.
\81\ See, e.g., Public Law 117-169, codified at 42 U.S.C. 7432-
7438. We also note that CAA section 211(o)(2)(B)(ii) requires the
EPA to consider ``the impact of the production and use of renewable
fuels on the environment, including on . . . climate change,'' among
many other factors, in setting volumes under the RFS program. 42
U.S.C. 7545(o)(2)(B)(ii).
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The EPA notes that Congress has continued to revise these air
pollutant-specific measures and nonregulatory tools as part of an
ongoing national debate over the appropriate response to global climate
change concerns. On July 4, 2025, President Trump signed into law
significant new legislation enacted by Congress, the One Big Beautiful
Bill Act (OBBB),\82\ which repealed a number of relevant measures
adopted in the IRA and rescinded the EPA's appropriations to carry out
a number of funding programs related to GHG emissions. Among other
things, Congress prohibited the Agency from collecting the waste
emission charge for methane for ten years beyond the original statutory
collection date, rescinded funding to administer grant programs in CAA
sections 132 and 135-38, and repealed CAA section 134, which had
included a section-specific definition of ``greenhouse gas'' applicable
to the grant
[[Page 36307]]
program set out in that section.\83\ We propose that this legislation,
which was the product of substantial national debate and revised and
rescinding funding for provisions of the IRA that were themselves the
product of substantial national debate, indicates that the EPA erred in
attempting to resolve significant policy issues on its own accord in
the Endangerment Finding.
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\82\ Public Law 119-21.
\83\ 42 U.S.C. 7434(c)(2) (2022).
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Congress has also recently disapproved several actions taken by the
EPA with respect to GHG emissions. On May 19, 2025, President Trump
signed into law a resolution adopted by Congress under the
Congressional Review Act (CRA) to void our final rule implementing the
waste emission charge added to the CAA in 2021.\84\ And on June 12,
2025, President Trump signed into law three resolutions adopted by
Congress under the CRA to void waivers we granted under CAA section 209
that allowed California and participating States to enforce GHG
emission regulations for motor vehicles and engines, up to and
including zero-emissions standards that mandated a shift to electric
vehicles.\85\ We propose that these disapproval resolutions further
demonstrate the economic and political significance of the EPA's GHG
emission regulations and reinforce the understanding that Congress
intends to reserve such major questions of policy for itself. See West
Virginia, 597 U.S. at 731-32.
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\84\ Public Law 119-2; see 90 FR 21225 (May 19, 2025).
\85\ H.J. Res. 87; H.J. Res. 88; H.J. Res. 89; see also Diamond
Alt. Energy, LLC v. EPA, No. 24-7, slip op. at 4 n.1 (U.S. June 20,
2025); Statement by the President (June 12, 2025): https://www.whitehouse.gov/briefings-statements/2025/06/statement-by-the-president/.
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Proposed Conclusion. Under our proposal that the major questions
doctrine applies, we propose to conclude that the EPA lacks the ``clear
congressional authorization'' required for the novel approach taken in
the Endangerment Finding and resulting GHG emission standards and must
rescind these actions. West Virginia, 597 U.S. at 723 (quoting UARG,
573 U.S. at 324). We propose that our statutory authority under CAA
section 202(a) to ``prescribe . . . standards'' does not clearly
authorize the EPA to regulate in response to global climate change
concerns or, in issuing such regulations, to mandate a shift from
gasoline-powered vehicles to electric vehicles.
In West Virginia, the Supreme Court held that our authority ``to
establish emission caps at a level reflecting `the application of the
best system of emission reduction . . . adequately demonstrated' '' did
not clearly authorize the EPA to issue emission guidelines that
addressed global climate change concerns by mandating a shift away from
coal-generated electricity. 597 U.S. at 732. Similarly, in UARG, the
Court held that our PSD and Title V authorities could not be extended
to GHG emissions because those provisions ``are designed to apply to,
and cannot rationally be extended beyond, a relative handful of large
sources capable of shouldering heavy substantive and procedural
burdens.'' 573 U.S. at 303.
We propose that these cases control the analysis of our authority
under CAA section 202(a). As in West Virginia, our statutory authority
and the findings required to invoke that authority do not clearly
authorize the approach taken in the Endangerment Finding and subsequent
regulations. And as in UARG, our statutory authority to ``prescribe . .
. standards'' for emissions of certain air pollutants does not clearly
authorize using the CAA's vehicle-emission control scheme to address
global climate change. As discussed above, the Endangerment Finding did
not limit itself to considering the impacts of GHG emissions from new
motor vehicles and engines. Rather, the Endangerment Finding reviewed
the totality of adverse impacts from climate change attributed to all
anthropogenic sources of GHG emissions worldwide and asserted
jurisdiction over CAA section 202(a) sources by finding they
contributed to such impacts by emitting more than de minimis quantities
of GHGs. That understanding has permeated our GHG emission rulemakings
since 2009, and we have attempted to apply that framework to our
distinct regulatory authorities for stationary sources and aircraft.
In Massachusetts, the Supreme Court disagreed with the EPA's
argument that GHGs were not ``air pollutants'' because Congress had not
revisited CAA section 202(a) in amending the CAA in 1990. 549 U.S. at
512-13. The Court found that our reliance on Brown & Williamson to
support that argument was misplaced because unlike the ban on tobacco
products at issue in that case, ``EPA jurisdiction would lead to no
such extreme measures.'' Id. at 531. The Court also found that unlike
the Food and Drug Administration's earlier statements on tobacco
products, ``EPA had never disavowed the authority to regulate
greenhouse gases'' and had issued a memorandum in 1998 suggesting that
we had such authority. Id.
We propose that Massachusetts did not consider or have reason to
interpret the scope of the EPA's authority under CAA section 202(a)
given our position in the 2003 Denial that GHGs are not ``air
pollutant[s]'' under any provision of the statute. Rather, we propose
Massachusetts rejected our position that GHGs are ``categorically''
excluded from the CAA and remanded for the Administrator to determine
whether four GHGs met the standard in CAA section 202(a). UARG, 573
U.S. at 320. We further propose that Massachusetts must be read
together with the Supreme Court's decisions in West Virginia and UARG,
which applied the major questions doctrine to statutory provisions
similar to CAA section 202(a). To that end, we seek comment on whether
Massachusetts applied the major questions doctrine in the first
instance,\86\ and, if it did, whether that analysis informs the meaning
of CAA section 202(a) on its own terms and in light of UARG and West
Virginia. Finally, we propose that the EPA's course of rulemaking has
not been limited to emission standards as anticipated in Massachusetts.
We seek comment on whether a new major questions doctrine analysis is
required because the EPA's rulemakings in response to the Endangerment
Finding have included electric vehicle mandates that require shifting
the national vehicle fleet from one type of vehicle and vehicle fuel to
another.
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\86\ We note that recent Supreme Court decisions have not cited
Massachusetts as a precedent applying, or declining to apply, the
major questions doctrine. See, e.g., Nebraska, 600 U.S. 477; West
Virginia, 597 U.S. 697.
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B. Alternative Rationale for Proposed Rescission
In the alternative, the EPA proposes that even if CAA section
202(a) could be read to authorize prescribing GHG emission standards
for new motor vehicles and engines, the Endangerment Finding
unreasonably applied the statutory standard for regulation to the
scientific record and should be rescinded on that basis. This
subsection proposes several reasons that the Administrator would
exercise his discretionary judgment differently today in light of
intervening legal and scientific developments that appear to undermine
the assumptions, methodologies, and conclusions of the Endangerment
Finding.
1. Climate Science Discussion
The Administrator reviewed available information, including the
most recently available scientific information, bearing on the
assumptions and conclusions in
[[Page 36308]]
the Endangerment Finding, the impacts of global GHG concentrations on
public health and welfare in the United States, and the relative
contribution of domestic emissions from new motor vehicles and engines
to global GHG concentrations. As previously explained, this review
included the 2025 CWG Draft Report, which analyzes empirical data,
peer-reviewed studies, and available scientific information bearing on
direct human influence on ecosystems and climate, climate response to
CO2 emissions, and impacts on ecosystems and society.\87\
The Administrator also considered available assessments by the U.S.
Government and relevant international bodies, including the Third,
Fourth, and Fifth NCAs reported by the USGCRP and AR5 and AR6 by the
United Nations IPCC. The Administrator also considered critiques of the
NCAs, and the Fifth NCA in particular, and reviewed these analyses for
consistency with OMB information quality guidelines \88\ and the
transparency and reliability requirements of Executive Order 14303,
``Restoring Gold Standard Science.'' \89\
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\87\ As stated earlier, the 2025 CWG Draft Report was provided
to the EPA on May 27, 2025, and was reviewed and relied upon in
formulating this proposal. The EPA understands that DOE is releasing
an updated version of the CWG draft report and seeking public
comment on the updated report, which includes additional information
and typographical corrections that the EPA did not rely upon in
formulating this proposal. Interested parties may review and comment
on the updated version of the CWG draft report for consideration as
part of DOE's efforts at https://www.energy.gov/topics/climate.
\88\ 67 FR 8452 (Feb. 22, 2002).
\89\ Executive Order 14303, 90 FR 22601 (May 29, 2025).
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The Endangerment Finding itself acknowledged significant
uncertainties related to climate change and its potential impacts when
it stated that the ``inherent uncertainty in the direction, magnitude
and/or rate of certain future climate change impacts opens up the
possibility that some changes could be more or less than expected, and
the possibility of unanticipated outcomes.'' 74 FR 66524. Specifically,
the Endangerment Finding identified uncertainties including, but not
limited to: the net health impacts of a temperature increase due to
decreases in cold-related mortality, 74 FR 66497, 66526; increases in
allergenic illnesses and pathogen borne disease vectors, 74 FR 66498;
food production and crop yields, including the scope of potential
beneficial impacts from climate change, 74 FR 66498, 66535; temperature
at the end of the 21st Century, 74 FR 66519; records of temperature
before 1600 A.D., 74 FR 66523; estimates and future projections of
anthropogenic aerosols and their respective heating or cooling effects,
74 FR 66519; the extent to which human-induced climate change affects
the intensity and frequency of extreme weather events, 74 FR 66531; and
emissions from future fleet motor vehicles, which could be impacted by
a number of technological, economic, and independent regulatory
factors, 74 FR 66543.
With respect to projected increases in GHG concentrations and
global temperatures, the projections relied upon in the Endangerment
Finding appear unduly pessimistic in light of empirical observations
made after it was finalized in 2009 through 2024. The Endangerment
Finding relied primarily on IPCC AR4 to predict global temperature
increases between 1.8 and 4 degrees Celsius by 2100, an extremely wide
and variable range that necessarily impacts the existence, extent, and
severity of anticipated dangers to public health and welfare. 74 FR
66519. However, as previously noted, IPCC scenarios depicting worst-
case, ``business as usual'' assessments have been criticized as
misleading (2025 CWG Draft Report at 16),\90\ and empirical data
suggest that actual GHG emission concentration increase and
corresponding warming trends through 2025 have tracked the IPCC's more
optimistic scenarios (2025 CWG Draft Report at 18).\91\ Recent
scientific analyses propose that this divergence may be explained by
greater capacity for the climate to reuptake GHGs in the atmosphere
through natural processes. Terrestrial ecosystems have demonstrated a
greater than anticipated sensitivity to elevated CO2
concentrations in the form of enhanced plant growth, which results in
greater removal of CO2 from the atmosphere as plants take up
CO2 and return it to the soil through natural life cycles.
Similarly, the oceans have demonstrated a greater capacity to take up
and process CO2 (including through aquatic plant life)
without resulting in the anticipated negative impacts on pH and ocean
ecosystems, including coral reefs (2025 CWG Draft Report at 6-9, 18-
20).\92\
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\90\ See also Hausfather, Z. & Peters, G.P. (2020). Emissions--
the `business as usual' story is misleading. Nature, 577, 618-620:
https://doi.org/10.1038/d41586-020-00177-3; Burgess, M.G. et al.
(2021). IPCC baseline scenarios have over-projected CO2
emissions and economic growth. Environmental Research Letters, 16,
014016: https://doi.org/10.1088/1748-9326/abcdd2; Pielke, R., &
Ritchie, J. (2020). Systemic Misuse of Scenarios in Climate Research
and Assessment Social Sciences Research Network. SSRN: http://doi.org/10.2139/ssrn.3581777.
\91\ See also Hausfather, Z. et al. (2019). Evaluating the
Performance of Past Climate Model Projections. Geophysical Research
Letters, 47(1): https://doi.org/10.1029/2019GL085378; Scaffeta, N.
(2023). CMIP6 GCM ensemble members versus global surface
temperatures. Climate Dynamics, 60, 3091-3120: https://doi.org/10.1007/s00382-022-06493-w; McKitrick, R. & Christy, J. (2020).
Pervasive Warming Bias in CMIP6 Tropospheric Layers. Earth and Space
Science, 7(9), e2020EA001281: https://doi.org/10.1029/2020EA001281;
Karl, T.R. et al. (2006). Temperature Trends in the Lower
Atmosphere: Steps for Understanding and Reconciling Differences.
U.S. Climate Change Science Program, Subcommittee on Global Change
Research.
\92\ See also Browman, H.I. (2016). Applying organized
scepticism to ocean acidification research. ICES Journal of Marine
Science, 73(3), 529.1-536: https://doi.org/10.1093/icesjms/fsw010;
Clements, J.C. et al. (2022). Meta-analysis reveals an extreme
``decline effect'' in the impacts of ocean acidification on fish
behavior. PLOS Biology, 20(2), e3001511: https://doi.org/10.1371/journal.pbio.3001511; Friedlingstein, P. et al. (2024). Global
Carbon Budget 2024. Earth System Science Data, 14(4): https://essd.copernicus.org/preprints/essd-2024-519; Haverd, V. et al.
(2020). Higher than expected CO2 fertilization inferred
from leaf to global observations. Global Change Biology, 26, 2390-
2402: https://doi.org/10.1111/gcb.14950; Zeng, Z. et al. (2017).
Climate mitigation from vegetation biophysical feedbacks during the
past three decades. Nature Climate Change, 7, 432-436: https://doi.org/10.1038/nclimate3299.
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Relatedly, recent empirical data and analyses suggest that the
Endangerment Finding was unduly pessimistic in attributing health risks
from heat waves to increases in global temperature. Notwithstanding
increased public attention to heat waves, the data suggest that
domestic temperatures peaked in the 1930s and have remained more or
less stable, in relative terms, since those highs (2025 CWG Draft
Report at 57-60). Moreover, increased urbanization trends contribute to
localized changes in temperature, including because an urban footprint
traps heat and frustrates natural heat-cycling capacity at a localized
and low-atmospheric level (2025 CWG Draft Report at 21-22). Contrary to
the Endangerment Finding's assumptions, data continue to suggest that
mortality risk from cold temperatures remains by far the greater threat
to public health in the United States and around the world at the
aggregate level (2025 CWG Draft Report at 112).\93\ Although the risk
of heat waves featured prominently in the Endangerment Finding, the
Administrator acknowledged at the time that significant uncertainties
existed about the relative benefits and risks in the United States, and
the data since 2009 suggest that the balance of climate change as a
whole appears to skew
[[Page 36309]]
substantially more than previously recognized by the EPA in the
direction of net benefits, or is at least too uncertain to establish a
credible and reliable finding of actionable risk, as discussed further
below.
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\93\ See also Zhao, Q. et al. (2021). Global, regional, and
national burden of mortality associated with non-optimal ambient
temperatures from 2000 to 2019: a three-stage modelling study. The
Lancet Planetary Health, 5(7): https://doi.org/10.1016/s2542-5196(21)00081-4; Gasparini, A. et al. (2015). Mortality risk
attributable to high and low ambient temperature: a multicounty
observational study. The Lancet, 386(9991), 369-375: https://doi.org/10.1016/S0140-6736(14)62114-0.
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With respect to extreme weather events, the Endangerment Finding
projected adverse health impacts from increased frequency and severity
of hurricanes, flooding, and wildfires. E.g., 74 FR 66498. Recent data
and analyses suggest, however, that despite increased public attention
and concern, such extreme weather events have not demonstrably
increased relative to historical highs (2025 CWG Draft Report at 65-72,
111).\94\ In reviewing the assumptions and conclusions regarding
extreme weather events in the Endangerment Finding, the empirical bases
asserted appear to be more generalized and unsupported than previously
believed and no longer inspire the same degree of confidence. The
Administrator further notes that the risks anticipated in the
Endangerment Finding resulted, in part, from the Agency's decision at
the time to categorically exclude consideration of adaptation and
mitigation that should have been incorporated into the analysis as
credible and relevant information. We propose that the data on weather
events, coupled with the Agency's decision to exclude mitigation and
adaptation information from the analysis, fatally undermines the
Endangerment Finding's conclusions in this respect.
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\94\ See also Masson-Delmotte, V. et al. (2021) Climate Change
2021: The Physical Science Basis. Contribution of Working Group I to
the Sixth Assessment Report of the Intergovernmental Panel on
Climate Change. Cambridge University Press: https://doi.org/10.1017/9781009157896; Klotzbach, P.J. et al. (2018). Continental U.S.
Hurricane Landfall Frequency and Associated Damage: Observations and
Future Risks. Bulletin of the American Meteorological Society,
99(7), 1359-1376: https://doi.org/10.1175/BAMS-D-17-0184.1;
Hodgkins, G.A. et al. (2017). Climate-driven variability in the
occurrence of major floods across North America and Europe. Journal
of Hydrology, 552, 704-717: https://doi.org/10.1016/j.jhydrol.2017.07.027; Wuebbles, D.J. et al. (2017). Climate Science
Special Report: Fourth National Climate Assessment, Volume I. U.S.
Global Change Research Program: http://doi.org/10.7930/J0J964J6;
Hodgkins, G.A. et al. (2017). Climate-driven variability in the
occurrence of major floods across North America and Europe. Journal
of Hydrology, 552, 704-717: https://doi.org/10.1016/j.jhydrol.2017.07.027: https://doi.org/10.1016/j.jhydrol.2017.07.027.
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The Endangerment Finding also identified public health and welfare
impacts from projected increases in sea level and related weather and
climactic events. However, on this issue, too, recent data and analyses
suggest that aggregate sea level rise has been minimal, at least with
respect to impacts on the United States, and that sea level has risen
in some domestic localities while falling in others (2025 CWG Draft
Report at 75-80). The Administrator also questions whether it was
appropriate for the Endangerment Finding to exclude any analysis of
adaptation with respect to sea level rise in particular. Population
growth, infrastructure development, and local and regional planning
decisions have been dynamic in coastal areas since 2009, with different
trends in different coastal areas and different choices made
independently of the EPA's regulatory actions by state and local
governments and private entities. The lack of analysis of adaptation
generally, and particularly with respect to sea level rise, reduces
confidence in the reasonableness, accuracy, and reliability of the
assumptions and conclusions in the Endangerment Finding.
The difficulties with parsing the scientific record continue, and
they go to the root of what methodologies should be given most credence
in making any scientific determinations. The Endangerment Finding
consistently cites climate models as showing or predicting warming
trends, melting ice, anthropogenic droughts, shrinking snowpack, damage
to aquatic systems of life, and increased ocean temperature and
acidity. E.g., 74 FR 66523, 66532. However, the data relied upon as
inputs to these models may be based on inaccurate assumptions. (2025
CWG Draft Report at 14-22).\95\ To name but a few instances: the
Northern hemispheric winter snow cover has not decreased in line with
the models used in the Endangerment Finding; aquatic life is largely
adapted for and has undergone oceanic pH changes throughout the Earth's
history, and the data used by the Endangerment Findings and predictions
of coral decline has not been supported by empirical data showing an
unexpected growth in coral reef ecosystems (2025 CWG Draft Report at 7-
12, 40-41).\96\ In addition, the models relied upon by the Endangerment
Finding may be incorrect with regard to warming in the U.S. Corn Belt
given the divergence of recent empirical data from projected trends
(2025 CWG Draft Report at 32-47).
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\95\ See also McKitrick, R. et al. (2012). Long-Term Forecasting
of Global Carbon Dioxide Emissions: Reducing Uncertainties Using a
Per Capita Approach. Journal of Forecasting, 32(5), 435-451: https://doi.org/10.1002/for.2248.
\96\ See also Connolly, R. et al. (2019). Northern Hemisphere
Snow-Cover Trends (1967-2018): A Comparison between Climate Models
and Observations. Geosciences, 9(3), 135: https://doi.org/10.3390/geosciences9030135; Annual Summary Report of Coral Reef Condition
2021/22. Continued coral recovery leads to 36-year highs across two-
thirds of the Great Barrier Reef. (2022). Australian Institute of
Marine Science: https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2021-22.
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The Administrator is also troubled by the Endangerment Finding's
seemingly inconsistent treatment of the nature and extent of the role
human action with respect to climate change. The Endangerment Finding
attributes the entirety of adverse impacts from climate change to
increased GHG concentrations, and it attributes virtually the entirety
of increased GHG concentrations to anthropogenic emissions from all
sources. But the causal role of anthropogenic emissions is not the
exclusive source of these phenomena, and any projections and
conclusions bearing on the issue should be appropriately discounted to
reflect additional factors. Moreover, recent data and analyses suggest
that attributing adverse impacts from climate change to anthropogenic
emissions in a reliable manner is more difficult than previously
believed and demand additional analysis of the role of natural factors
and other anthropogenic factors such as urbanization and localized
population growth (2025 CWG Draft Report at 14-22, 82-92).\97\
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\97\ McKitrick, R. (2013). Encompassing tests of socioeconomic
signals in surface climate data. Climatic Change, 120(1-2), 95-107:
https://doi.org/10.1007/s10584-013-0793-5; McKitrick, R. &
Nierenberg, N. (2010). Socioeconomic Patterns in Climate Data.
Journal of Economic and Social Measurement, 35(3-4), 149-175:
https://doi.org/10.3233/JEM-2010-0336; McKitrick, R. (2021).
Checking for model consistency in optimal fingerprinting: a comment.
Climate Dynamics, 58(1-2), 405-411: https://doi.org/10.1007/s00382-021-05913-7; McKitrick, R. (2023). Total least squares bias in
climate fingerprinting regressions with heterogeneous noise
variances and correlated explanatory variables. Environmetrics,
35(2), e2835: https://doi.org/10.1002/env.2835; McKitrick, R.
(2022). On the choice of TLS versus OLS in climate signal detection
regression. Climate Dynamics, 60, 359-374: https://doi.org/10.1007/s00382-022-06315-z; Connolly, R. et al. (2021). How much has the sun
influenced Northern Hemisphere temperature trends? An ongoing
debate. Research in Astronomy and Astrophysics, 21(6), 131: https://doi.org/10.1088/1674-4527/21/6/131.
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In addition, and as noted in particular contexts above, the
Administrator is concerned that the Endangerment Finding did not
adequately balance the projected adverse impacts attributed to global
climate change with the potential benefits to the United States of
increased GHG concentrations, and increased CO2
concentrations in particular. Unlike virtually every other gas
regulated under the CAA, CO2 is necessary for human, animal,
and plant life, and advances public health and welfare by directly
impacting plant growth and therefore the price and availability of
food, the success of American agricultural and related
[[Page 36310]]
industries, and the traditional capacity of the United States to export
significant food supplies around the world for economic and
humanitarian purposes. Recent data and analysis show that even marginal
increases in CO2 concentrations have substantial beneficial
impacts on plant growth and agricultural productivity, and that this
benefit has been significantly greater than previously believed (2025
CWG Draft Report at 6-7, 104-09).
The Administrator also questions the decision in the Endangerment
Finding to consider together all six ``well-mixed'' GHGs rather than
analyzing the properties and impacts of each on an individual basis. 74
FR 66537. As noted in the 2008 ANPRM, new motor vehicle and engine
emissions of the four GHGs they actually emit have fluctuated and
diverged over time, and each has different interactions with the
climate and natural environment. Nevertheless, the Endangerment Finding
did not undertake individual analyses of these four GHGs and, in fact,
aggregated them together along with two additional GHGs not emitted by
motor vehicles or motor vehicle engines, thereby undermining the
transparency, reliability, and usefulness of the findings. We propose
that each of the collectively treated GHGs demonstrates different
chemical properties, exhibits different interactions with the natural
environment, and present different emissions profiles. The Agency did
not analyze, for example, whether the three GHGs other than
CO2 emitted by new motor vehicles and engines could be
addressed separately in a manner that would impact the ultimate
conclusions of endangerment and contribution. Nor did the Agency
analyze whether HFCs, which are emitted not by engines but by air
conditioning units, could be addressed separately under CAA section
202(a) or another authority in a manner that would impact the ultimate
conclusions of endangerment and contribution.
Finally, the Administrator notes that the analyses relied upon in
the Endangerment Finding, including the assessment reports of the IPCC
and USGCRP that were available at the time and the subsequent
iterations of those reports that have been published since 2009, have
been criticized on process and quality grounds. Recently, several
public watchdog organizations have raised concerns related to the
process and quality of the Fifth NCA, which shares the underlying
assumptions and conclusions of prior NCAs and IPCC reports. The groups
state that NCA5 does not meet the requirements under Executive Order
14303 and deviated from OMB guidelines on quality, objectivity,
utility, and integrity of information disseminated by Federal agencies.
The Administrator takes each of these concerns seriously and seeks
public comment on the validity of these concerns and how they should be
taken into account when determining whether to finalize any of the
alternatives proposed in this action.
2. Proposed Conclusions
Based on this review of the Endangerment Finding and the most
recently available scientific information, data, and studies, the
Administrator proposes to find, in an exercise in discretionary
judgment, that there is insufficient reliable information to retain the
conclusion that GHG emissions from new motor vehicles and engines in
the United States cause or contribute to endangerment to public health
and welfare in the form of global climate change. This proposed
conclusion is animated both by the Administrator's commitment to
analyzing the statutory standard as a cohesive whole and by the
scientific record, which includes too many analytical gaps,
uncertainties, and speculative predictions to reach an affirmative
endangerment finding and promulgate corresponding emission standards
based on such a finding.
As explained above, the Administrator previously asserted in the
Endangerment Finding that CAA section 202(a) grants ``procedural
discretion'' to sever the findings that trigger regulation from
consideration of the resulting regulations and to sever the
endangerment analysis from the causation or contribution analysis. We
propose that the Administrator would now exercise such discretion
differently to ensure greater reliability, transparency, and public
accountability in the EPA's invocation of regulatory authority. We note
that as a result of the approach taken in the Endangerment Finding, the
Administrator's conclusions with respect to new motor vehicles and
engines were never subject to SAB review as required by the CAA, and
that the public never had the opportunity to participate in a
rulemaking that paired the consideration of risk with discussion of the
regulatory response, including the effectiveness and cost of potential
regulatory approaches. We propose that CAA section 202(a) operates as
an integrated whole, and that the EPA's administration of that
provision should reflect a reasoned consideration of all relevant
factors that is not artificially severed into distinct findings and
rulemakings across time.
In addition, we propose that even if intervening legal developments
have not foreclosed the regulation of GHG emissions from new motor
vehicles and engines under CAA section 202(a), they provide a
reasonable basis for the Administrator to approach the inquiry with
greater caution today than was applied in the Endangerment Finding. At
a minimum, Loper Bright confirms that the EPA can no longer rely on
statutory silence or ambiguity to imply authorities and discretion not
expressly conferred by statute. In exercising the judgment required by
CAA section 202(a), the Administrator would choose to adhere as closely
as possible to the statutory language, prior Agency implementation of
that language, and the initial approach set out in the 2008 ANPRM. We
propose that the Administrator's new approach requires rescinding the
Endangerment Finding as fundamentally inconsistent with the framework
set out in this proposed alternative.
Moreover, we propose that the Administrator would not now find, in
light of the ongoing uncertainties in relevant scientific data and
analyses bearing on the question, that the evidence is sufficiently
reliable to determine that GHG emissions from new motor vehicles and
engines meet the standard for regulation in CAA section 202(a). As
discussed in the preamble, the Administrator reviewed the scientific
record as part of the reconsideration process and no longer has the
degree of confidence previously expressed in the analyses relied upon
in the Endangerment Finding, the attribution decisions made in the
Endangerment Finding, and the balance of projected adverse impacts and
beneficial impacts of climate change struck in the Endangerment
Finding.
The EPA seeks comment, for the first time since the 2009
Endangerment Finding was proposed, on whether, due to new scientific
information and developments since the 2009 Endangerment Finding, there
is a strong enough scientific record to support an affirmative finding
that GHG emissions from section 202(a) sources cause or contribute to
air pollution which may reasonably be anticipated to endanger public
health or welfare. Prompt action is needed to address these concerns,
and the Administrator looks forward to stakeholder input on the
continuing vitality of the assumptions, predictions, and conclusions
animating the 2009 Endangerment Finding.
Additionally, the EPA seeks comment on, if the EPA were to make
such a
[[Page 36311]]
finding, whether a new comment period would be required and what
information would be necessary to provide such a finding. To aid in the
EPA's decision making, we also seek comment on the breadth of the
Administrator's discretion to exercise judgment by rejecting the
approach taken in the Endangerment Finding and the results of adopting
a different approach. We also seek comment on any additional aspects of
the Endangerment Finding that may have fallen short of the
administrative law requirement that agency action be reasonable and
reasonably explained. Conversely, we seek comment on why the approach
taken in the Endangerment Finding remains reasonable given the legal
and scientific developments discussed in this proposal, and the impact,
if any, of the EPA's denial of rulemaking petitions in 2022 and 2010 on
this alternative proposal. As previously noted, we are also seeking
comment on whether the denials in 2022 and 2010 were unlawful for any
additional reasons not explored explicitly in this proposal.
V. Separate Bases for Proposed Repeal of GHG Emission Standards
In this section, the EPA proposes repealing existing GHG emission
standards for reasons unrelated to the decision to rescind or retain
the Endangerment Finding. CAA section 202(a) requires us to consider
additional factors before emission standards issued in response to an
endangerment finding may go into effect, including cost, the useful
life of the vehicles or engines, and the availability of ``requisite
technology.'' \98\ Consistent with the language and structure of the
statute and the Supreme Court's express reservation of this question in
Massachusetts, we propose to conclude that policy considerations may be
taken into account, at a minimum, when setting standards in response to
an endangerment finding or, as here, when determining whether to
maintain standards already established.\99\
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\98\ See 42 U.S.C. 7521(a)(1)-(2), (a)(3)(B).
\99\ See Massachusetts, 549 U.S. at 534-35 (``We need not and do
not reach the question whether on remand EPA must make an
endangerment finding, or whether policy concerns can inform EPA's
actions in the event that it makes such a finding.'').
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Specifically, we are proposing that there is no ``requisite
technology'' for emission control for light- and medium-duty vehicles
because reducing GHG emissions from such vehicles to zero would not
measurably impact GHG concentrations in the atmosphere or the rate of
global climate change. Relatedly, we are proposing that there is no
``requisite technology'' for emission control for heavy-duty vehicles
and engines, even if considered in combination with light- and medium-
duty vehicle standards. Finally, we are proposing that GHG emission
standards may harm, rather than advance, public welfare as defined in
the CAA by reducing fleet turnover that improves air quality, safety,
consumer choice, and economic opportunity.
Each of these proposals would, if finalized, serve as an
independent and sufficient basis for repealing the relevant GHG
emission standards as proposed in section VI of this preamble. The EPA
seeks comment on all aspects of these alternative proposed bases for
repeal of the GHG emission standards as indicated in the remainder of
this section.
A. There Is No Requisite Technology for Light- and Medium-Duty Vehicles
That Meaningfully Addresses the Identified Dangers of the Six ``Well-
Mixed'' GHGs
The EPA proposes to repeal GHG emission standards for light- and
medium-duty vehicles because no technology for this source category is
capable of preventing or controlling the ``air pollution'' identified
as a danger to public health and welfare in the Endangerment Finding,
i.e., global concentrations of GHGs in the upper atmosphere. CAA
section 202(a)(1) provides that new motor vehicles and engines may
comply with emission standards ``as complete systems'' or by
``incorporat[ing] devices to prevent or control'' the air pollution
that endangers public health or welfare.\100\ CAA section 202(a)(2)
further provides that emission standards cannot go into effect until
``after such period as the Administrator finds necessary to permit the
development and application of the requisite technology, giving
appropriate consideration to the cost of compliance within such
period.'' \101\
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\100\ 42 U.S.C. 7521(a)(1).
\101\ 42 U.S.C. 7521(a)(2).
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As noted elsewhere in this preamble, GHG emissions from the United
States were 11 percent of global GHG emissions in 2022,\102\ down from
23.5 percent in 2005.\103\ The U.S. transportation sector accounted for
28 percent of domestic GHG emissions in 2022, and light- and medium-
duty vehicles accounted for 57 percent of U.S. transportation sector
GHG emissions.\104\ Taken together, the best available data indicate
that GHG emissions from light- and medium-duty vehicles in the United
States amounted to approximately 1.8 percent of global GHG emissions in
2022. Reducing GHG emissions from light- and medium-duty vehicles in
the United States to zero would result in a 1.8 percent decrease in
global GHG emissions, which corresponds to an approximate 3 percent
reduction in predicted warming trends (2025 CWG Draft Report at
130).\105\ To note, these percentages do not account for trends
demonstrating that the United States has been decreasing absolute GHG
emissions while other countries like China are significantly increasing
their GHG emissions.\106\
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\102\ U.S. Environmental Protection Agency. (Last updated Mar.
31, 2025). Global Greenhouse Gas Overview: https://www.epa.gov/ghgemissions/global-greenhouse-gas-overview.
\103\ 74 FR 66539.
\104\ U.S. Environmental Protection Agency. (Last updated July
1, 2025). Inventory of U.S. Greenhouse Gas Emissions and Sinks:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks.
\105\ See also U.S. Transportation Sector Greenhouse Gas
Emissions 1990-2022. (2024). United States Environmental Protection
Agency 89 FR 11275 (Feb. 14, 2024); Statistical Review of World
Energy. (2024). Energy Institute: https://www.energyinst.org/statistical-review.
\106\ Crippa, M. et al. (2023). GHG emissions of all world
countries. Publications Office of the European Union: https://doi.org/10.2760/953322.
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Global warming trends from 1979 to 2023, the period with the best
available data, were determined to a precision (or margin of error) of
plus or minus 15 percent total (id.). An estimated 3 percent reduction
in global warming trends is well below the scientific threshold for
measurability and is not a reliable measure for regulatory purposes.
By defining global GHG concentrations in the upper atmosphere as
the relevant threat to public health and welfare in the United States,
the Endangerment Finding identified a problem that the regulatory tools
Congress provided under CAA section 202(a) are simply unable to
meaningfully address. Notably, that action defined the relevant ``air
pollution'' as six ``well-mixed'' GHGs, meaning the combination of GHGs
rather than an individual air pollutant that could be emitted by
certain sources at greater or lesser levels and would be more amenable
to effective prevention and control. 74 FR 66537. To qualify as a
``requisite technology'' with any measurable impact on the identified
danger, an engine design or device would need to remove GHGs already
present in the atmosphere and would no longer qualify as an emission
standard for the new motor vehicle or motor vehicle engine.
Additionally, the ``requisite technology'' to meet the identified
danger would, at minimum, require a complete change from internal
[[Page 36312]]
combustion engines to EVs or another zero-emissions technology. We
propose that this form of fuel switching is analogous to the
generation-shifting approach we attempted to take for existing
stationary sources and that was held to be illegal in West Virginia. As
explained further below, even a complete shift toward EVs or other
zero-emission vehicle and engine technologies in the United States
would not reliably and meaningfully reduce elevated global
concentrations of GHGs and, therefore, not reliably and meaningfully
reduce the risks of climate change asserted in the Endangerment
Finding. Given the relatively low share of total global anthropogenic
emissions, new motor vehicles and engines in the United States would
need to remove GHGs from the atmosphere to have the potential for a
reliable impact on GHG concentrations and potential impacts,
particularly when viewed in light of increased growth in foreign
emissions sources.
The EPA seeks comment on this proposed rationale, including on the
proper interpretation of ``requisite technology,'' the appropriate
standard for measuring pollution prevention and control, and the
scientific threshold for determining measurable impacts on trends in
climate change.
B. There Is No Requisite Technology for Heavy-Duty Vehicles That
Addresses the Identified Dangers of the Six ``Well-Mixed'' GHGs
For similar reasons, the EPA also proposes to repeal GHG emission
standards for heavy-duty vehicles because there is no requisite
technology capable of preventing or controlling the ``air pollution''
identified in the Endangerment Finding. Heavy-duty vehicles account for
an even lower percentage of GHG emissions in the U.S. transportation
sector than light- and medium-duty vehicles: 23 percent, as compared to
57 percent.\107\ Therefore, of the global GHG emissions in 2022, heavy-
duty vehicles contributed approximately 0.7 percent. If all heavy-duty
vehicles in the U.S. no longer emitted GHGs, that would only result in
a decrease of 0.7 percent of all worldwide GHG emissions. As noted in
the previous subsection, that low figure corresponds to a predicted
warming impact well below the measurability threshold because warming
trends are determined at a precision of plus or minus 15 percent (2025
CWG Draft Report at 130).
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\107\ U.S. Environmental Protection Agency. (Last updated July
1, 2025). Inventory of U.S. Greenhouse Gas Emissions and Sinks:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks.
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The EPA establishes light- and medium-duty vehicle and heavy-duty
vehicles separately under distinct grants of authority in CAA section
202(a) and must justify actions taken with respect to each source
category separately. We note, however, that even when considered
together, the impact of reducing all GHG emissions from motor vehicles
and motor vehicle engines to zero would not result in a measurable
impact on trends in climate change. A combined 2.5 percent reduction in
global GHG emissions would not result in a more than de minimis impact
on trends in climate change and would not demonstrate a requisite
technology for regulatory purposes.
C. Eliminating GHG Emissions From All Motor Vehicles Would Be Futile
The EPA is proposing that the Agency must consider the impacts of
making an Endangerment Finding and cannot arbitrarily separate parts of
a sentence within different regulations. Here, we propose that this
interpretation means the Agency should not and need not make an
endangerment finding under CAA section 202(a)(1) when the regulatory
authority conferred by that provision would have no meaningful impact
on the identified dangers. As discussed in subparts A and B of this
section, we propose that there is no requisite technology that would
result in meaningful changes to the impacts of climate change. Whereas
the determination in subparts A and B was based on the statutory
language within CAA section 202(a)(2), this subpart is based on the
statutory language in CAA section 202(a)(1).
Specifically, we propose that when considering whether to make an
endangerment finding, the Administrator should consider the ability of
the EPA's CAA section 202(a)(1) authority to meaningfully address the
identified risks. As noted above, the Endangerment Finding itself
recognized that the relative contribution of GHG emissions to global
concentrations from new motor vehicles and engines in the United States
is small, and recent data and analyses demonstrate that the share has
significantly decreased since 2009. Under the circumstances, even a
complete elimination of all GHG emissions from new motor vehicles and
engines would not address the risks attributed to elevated global
concentrations of GHGs. We propose that this futility further
demonstrates that CAA section 202(a) does not, as a matter of text and
structure, authorize or require the EPA to prescribe emission standards
for GHG emissions from new motor vehicles and engines. We further
propose that it was improper for the Agency to attempt to get around
this problem in the Endangerment Finding by asserting that parties
regulated under CAA section 202(a) must ``do their part'' when, in
reality, only dramatic reduction in foreign emissions, as well as
reductions from domestic sources regulated under other provisions of
the CAA, would have any meaningful impact on the global climate change
concerns asserted in the Endangerment Finding. The CAA does not
authorize the EPA to regulate international sources of emissions, and
the statute provides distinct regulatory authority, subject to distinct
requirements and standards, for other domestic sources.
D. More Expensive New Vehicles Prevent Americans From Purchasing New
Vehicles That Are More Efficient, Safer, and Emit Fewer GHGs
The EPA also proposes to repeal GHG emission regulations for new
motor vehicle and motor vehicle engines because the resulting increase
in price disincentivizes consumers from purchasing new vehicles and
keeps less efficient vehicles on the road for longer.\108\ Complying
with our GHG emission standards often requires manufacturers to design
and install new and more expensive technologies, thereby increasing the
price of new vehicles and reducing consumer demand. More expensive new
vehicles are cost prohibitive for some consumers, and those consumers
are likely to turn to the used vehicle market or continue using an
older vehicle.\109\
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\108\ For additional discussion on this topic, see 85 FR 24174
(Apr. 30, 2020).
\109\ A discussion of the impact of higher vehicle prices on
slowing fleet turnover can be found at 85 FR 24626 (Apr. 30, 2020).
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With respect to commercial vehicles, it is widely understood that
many commercial vehicle owners and commercial fleet operators consider
the total cost of ownership in determining when to purchase new
commercial vehicles. The total cost of ownership involves many factors,
including, for example, not only vehicle price, but also owning and
operating costs (e.g., service and maintenance costs and fuel costs).
Depending on the impacts of the GHG regulations on the specific vehicle
category and the considerations relevant to the commercial vehicle
purchaser, the impacts of GHG regulations may result in a decrease in
new commercial vehicle sales. We also note that commercial vehicle
owners and fleet operators may incur additional costs
[[Page 36313]]
associated with ongoing compliance obligations under the GHG standards
for an applicable model year, including testing and reporting
requirements that are reflected in the total cost of ownership but not
necessarily the vehicle price.\110\
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\110\ See section VI.C of this preamble for a discussion of the
heavy-duty vehicle and engine GHG regulatory requirements and
compliance obligations.
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All other things being equal, an increase in the price of new
vehicles can result in consumers keeping their vehicles for longer
periods, delaying the purchase of new vehicles, and decreasing fleet
turnover. Contrary to the goals of the EPA's GHG emission standards and
the intended purpose of CAA section 202(a), a delay in fleet turnover
can negatively impact air quality because older vehicles tend to emit
higher levels of air pollutants, including criteria pollutants and
hazardous air pollutants, regulated by the EPA.\111\ Slowing fleet
turnover is of particular concern with respect to the EPA's 2024
vehicle GHG rules because of the large increase in vehicle technology
costs which will likely lead to large increases in purchase prices, and
the impact battery electric and fuel cell vehicle technologies will
have on purchasing decisions of consumers (for light-, medium-, and
heavy-duty vehicle buyers). Increased prices and some consumers
rejecting battery electric and fuel cell vehicle technologies may lead
consumers to hold on to their existing vehicles longer. Vehicles are
more likely to emit less air pollution with each subsequent model year
because of improvements in technology, ordinary wear and tear that
decreases the effectiveness of installed technology, and greater
stringency in more recent regulations for criteria pollutants and
hazardous air pollutants.
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\111\ A discussion of the impact of higher vehicle prices on
slowing fleet turnover and thus increasing emissions can be found at
85 FR 24186 and 25039 (Apr. 30, 2020).
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For these reasons, the EPA has serious concerns that its GHG
standards may be harming air quality by raising prices and reducing
fleet turnover. We seek comment on this proposed basis for repeal,
including on the economics of fleet turnover, the relative efficiency
and emission reductions achieved by newer vehicles, modeling of the
changes vehicle criteria pollutant and air toxic emissions as well as
changes in upstream emissions, modeling of potential changes in air
quality (including ozone and particulate matter) and the potential
costs to air quality of retaining standards that may slow fleet
turnover as compared to the potential benefits of retaining GHG
emission standards in response to global climate change concerns.
In addition, the EPA notes that greater availability of new
vehicles at lower prices furthers public welfare by promoting vehicle
safety and consumer choice. New vehicles must meet all Federal Motor
Vehicle Safety Standards (FMVSS), which NHTSA continually updates over
time to respond to new concerns and to incorporate improvements in
safety technology. Manufacturers install technologies to meet these
safety requirements and may also include newer safety features not
required by regulation. NHTSA has found that newer vehicles offer
improved safety features and designs, leading to reduced fatalities and
injuries in crashes relative to older vehicles.\112\ A delay in the
turnover of the fleet also could lead to a higher risk to drivers and
passengers and delay the safety benefits provided by new vehicles,
thereby harming the public welfare in a more direct way than the global
climate change impacts animating the EPA's GHG standards.
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\112\ U.S. Department of Transportation, National Highway
Traffic Safety Administration. How Vehicle Safety Has Improved Over
the Decades: https://www.nhtsa.gov/how-vehicle-safety-has-improved-over-decades.
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Moreover, the EPA notes that the ability to own a vehicle is an
important means to unlock economic freedom and participate in society
as an employee, consumer, and community member. Transportation mobility
is essential to economic and social mobility, and there are no readily
available substitutes for passenger vehicles in many urban and
virtually all non-urban communities throughout the United States. By
increasing the price of new vehicles and existing vehicles subject to
the standards at manufacture, our GHG emission standards may prevent
some people from accessing the benefits of vehicle ownership. For
example, in EPA's 2024 vehicle GHG rules, the EPA projected significant
increases in vehicle technology costs which we estimated would be
passed on to consumers as price increases.\113\ In addition, the 2025
OBBB ended the IRA's 30D new clean vehicle tax credit before the end of
2025 (while the IRA allowed for this tax credit through 2032). This
significant change will increase the effective price of many new
battery electric, plug-in hybrid electric, and fuel cell vehicles,
including leased vehicles.
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\113\ For a discussion of this topic, see chapter 4.2 of the
Multi-Pollutant Emissions Standards for Model Years 2027 and Later
Light-Buty and Medium-Duty Vehicles final rule RIA, https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P1019VPM.pdf, and Chapter 3 of
the Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles:
Phase 3 final rule RIA, https://nepis.epa.gov/Exe/ZyPDF.cgi/P101ABVT.PDF?Dockey=P101ABVT.PDF.
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The EPA seeks comment on these additional rationales, including on
whether such public welfare considerations can and should be considered
when prescribing and revising emission standards under CAA section
202(a). As noted earlier in this preamble, Congress defined ``effects
on welfare'' broadly in CAA section 302(h) to include, but not be
limited to, ``hazards to transportation, as well as effects on economic
values and on personal comfort and well-being.'' 42 U.S.C. 7602(h). We
seek comment on how to give effect to this statutory language as
incorporated into the reference in CAA section 202(a) to effects on
``public health or welfare.'' We further seek comment as a general
matter on whether the Endangerment Finding and resulting regulations
have resulted in disbenefits, that is, on any public health and welfare
harms that may flow from the Endangerment Finding and resulting
regulations themselves.
VI. Proposed Repeal of GHG Emission Standards
Consistent with the proposed rescission of the Endangerment Finding
in section IV.A and IV.B of this preamble, the additional
considerations in section V of this preamble, and the discussion of
legal authority in section III of this preamble, the EPA is proposing
to repeal all GHG emission standards for light-duty vehicles, medium-
duty vehicles, heavy-duty vehicles, and heavy-duty engines. This
includes emission standards for the subset of four of the six ``well-
mixed GHGs'' whose elevated concentrations in the upper atmosphere the
2009 endangerment finding identified as the ``air pollution'' in
question that are actually emitted by such vehicles and engines--
CO2, N2O, methane, and HFCs--as well as the
compliance provisions for the GHG standards. These proposed changes
would apply to all MYs of vehicles and engines, including MYs that have
completed manufacture prior to the effective date of any final rule.
Under the proposed revisions, manufacturers may in some cases
already be changing their production processes to apply updated
emission control information labels for vehicles and engines.
Manufacturers may also already be revising warranty statements provided
with their engines and vehicles. We also note that this
[[Page 36314]]
proposed action would not, if finalized, require manufacturers to adapt
immediately if doing so would raise timing concerns. Unlike the GHG
emission standards we propose to repeal, this proposed action would
increase flexibility and not mandate any particular technology
response. Manufacturers will have no vehicle technology mix constraints
which arise from the EPA GHG standards and will be free to produce a
range of technologies, including gasoline, diesel, alternative fuels,
and plug-in electric vehicles. Furthermore, we have adequate statutory
authority to approve manufacturers' requests to continue to offer a
warranty that is more generous than required under regulations, and to
include information on emission control information labels that is more
than required under the proposed regulations. Thus, we do not
anticipate material compliance difficulties on the part of
manufacturers if this repeal action is finalized as proposed.
In section VI.A of this preamble, we discuss the anticipated
impacts of the proposed repeal of GHG emission standards under CAA
section 202(a) on the overall regulatory scheme for parties currently
subject to the standards. As explained in this section and elsewhere in
this preamble, we are not proposing to reopen or substantively revise
any emission standards for criteria pollutants or hazardous air
pollutants or to reopen or substantively revise any regulatory
provisions related to NHTSA's CAFE standards or the EPA's role in
administering EPCA and EISA. Moreover, this proposed action would not
impact Federal preemption for motor vehicle and engine emission
standards under CAA section 209(a) or under EPCA and EISA, including
with respect to GHGs.
In section VI.B of this preamble, we describe the light-duty (LD)
and medium-duty (MD) vehicle program and the proposed changes to the
GHG regulations for that program. In section VI.C of this preamble, we
describe the heavy-duty (HD) engine and vehicle program and proposed
regulatory changes. We request comment on all proposed changes
described in this section, including on any additional regulatory
provisions for engines and vehicles that should be removed as part of
repealing the GHG standards or should be retained to effectuate
unrelated standards that we are not proposing to repeal or revise. To
aid in public participation, we have submitted a memorandum to the
docket that includes redline text highlighting all proposed changes to
the regulations.\114\
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\114\ Memorandum to Docket EPA-HQ-OAR-2025-0194, ``Redline
Version of EPA's Proposed Regulations for the Reconsideration of
2009 Endangerment Finding and Greenhouse Gas Vehicle Standards.''
August 2025.
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The EPA's engine and vehicle programs are codified in Title 40 of
the CFR. Specifically, the standard-setting parts for light- and
medium-duty vehicles are located in 40 CFR part 85 and 86. The
standard-setting part for heavy-duty engines is located in 40 CFR part
1036 and the standard-setting part for heavy-duty vehicles is 40 CFR
part 1037. Each standard-setting part includes regulations describing
emission standards and related requirements and compliance provisions
for certifying engines or vehicles. As explained in this section and
elsewhere in this preamble, the EPA is proposing to retain measurement
procedures, reporting requirements, and credit provisions for the
light-duty program necessary for demonstrating compliance with NHTSA's
CAFE standards and fuel economy labeling to meet our statutory
obligations under EPCA and EISA. We consider any changes to those
requirements as outside the scope of this rulemaking and may consider
changes to these provisions, as appropriate, in a future rulemaking.
Further, as explained in this section and elsewhere in this preamble,
we are not proposing to reopen or substantively revise emission
standards or compliance provisions related to criteria pollutant
exhaust emissions (i.e., oxides of nitrogen (NOX),
hydrocarbons (HC), particular matter (PM), and carbon monoxide (CO)),
air toxic emissions, or evaporative and refueling emissions.\115\ We
may consider those issues, as appropriate, in future rulemakings.
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\115\ In this proposed rulemaking, NOX, HC, PM, and
CO are sometimes described collectively as ``criteria pollutants''
because they are either criteria pollutants under the CAA or
precursors to the criteria pollutants ozone (O3) and PM.
---------------------------------------------------------------------------
A. Scope and Impacts of Proposed Repeal
The EPA is proposing to repeal all regulatory provisions relating
to our GHG emission programs for light- and medium-duty vehicles and
heavy-duty vehicles and engines on the bases set forth in sections
III.A, III.B, and IV of this preamble. If finalized, any one of these
alternative proposals would provide a sufficient basis for repealing
our existing GHG regulations for new motor vehicles and new motor
vehicle engines. Finalizing the proposed rescission of the Endangerment
Finding as set out in section IV.A would provide sufficient basis for
repeal because the EPA would lack statutory authority to regulate
emissions based on global climate change concerns under CAA section
202(a). Finalizing the proposed rescission of the Endangerment Finding
as set out in section IV.B would provide sufficient basis for repeal
because the Administrator would conclude that the scientific evidence
of endangerment and contribution is too uncertain to satisfy the
standard for regulation under CAA section 202(a). And finalizing the
proposed rationales set out in section V would provide sufficient basis
for repeal, separately or in combination, because the EPA would
conclude that our GHG emission standards do not further public health
and welfare and cannot go into effect.
The repeal proposed in this NPRM is limited to the regulatory
provisions for GHG emission standards found in 40 CFR parts 85, 86,
1036, and 1037, with minor conforming adjustments to unrelated emission
standards for new motor vehicles and engines in 40 CFR parts 600 and
1039. As detailed in subparts B and C of this section, this NPRM is not
proposing to revise emission standards for criteria pollutants or air
toxics. The EPA may reconsider and propose to revise the regulatory
provisions for those programs in a separate rulemaking action.
Similarly, this NPRM is not reopening or proposing to revise regulatory
provisions necessary for NHTSA's CAFE standards or the EPA's co-
administration of EPCA and EISA. Accordingly, we are not seeking public
comment on the substance of these distinct regulatory programs and will
consider such comments outside the scope of this rulemaking.
For this reason, the proposed repeal would not impact Federal
preemption under EPCA, as amended by EISA, related to fuel economy
standards. EPCA provides that when ``an average fuel economy standard
prescribed under this chapter is in effect, a State or a political
subdivision of a State may not adopt or enforce a law or regulation
related to fuel economy standards or average fuel economy standards for
automobiles covered by an average fuel economy standard under this
chapter'' \116\ unless the standards are identical or apply only to
vehicles obtained for the use of the State or political
subdivision.\117\ If finalized, this action would not reopen or revise
any fuel economy standards or alter the EPA's statutory role in co-
administering
[[Page 36315]]
any such standards, including NHTSA's CAFE standards.
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\116\ 49 U.S.C. 32919(a).
\117\ 49 U.S.C. 32919(b)-(c).
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The proposed repeal also would not impact Federal preemption of
emission standards for new motor vehicle and engine emission standards.
CAA section 209(a) provides that ``[n]o State or any political
subdivision thereof shall adopt or attempt to enforce any standard
relating to the control of emissions from new motor vehicles or new
motor vehicle engines subject to this part,'' including
``certification,'' ``inspection'' or ``approval'' requirements
``relating to the control of emissions from'' such vehicles or
engines.\118\ Because new motor vehicles and engines currently subject
to GHG emission standards would remain subject to Title II of the CAA,
the statute would continue to preempt ``any'' State or local ``standard
relating to the control of emissions.'' Relatedly, the CAA would
continue to preempt Federal common-law claims for GHG emissions because
``Congress delegated to EPA the decision whether and how to regulate''
such emissions. Am. Elec. Power Co. v. Connecticut, 564 U.S. 410, 426
(2011). We would retain our authority to prescribe emission standards
for any air pollutant that, in the Administrator's judgment, causes or
contributes to air pollution that may reasonably be anticipated to
endanger public health or welfare. The bases for repeal proposed in
this action would not foreclose us from regulating CO2,
methane, NOX, HFCs, PFCs, or SF6 emissions from
new motor vehicles or engines if the Administrator determines that one
or more of those gases meet the requirements for regulation under CAA
section 202(a), as discussed herein. As noted above, we seek comment on
the continued preemptive effect of the CAA in the event that the EPA
finalizes the proposed rescission or otherwise concludes that it lacks
authority to regulate GHG emissions under CAA section 202(a) or any
other specific regulatory provision of the CAA.
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\118\ 42 U.S.C. 7543(a).
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The EPA's engine and vehicle programs are codified in Title 40 of
the CFR. Specifically, the standard-setting parts for light- and
medium-duty vehicles are located in 40 CFR parts 85 and 86. The
standard-setting part for heavy-duty engines is located in 40 CFR part
1036 and the standard-setting part for heavy-duty vehicles is 40 CFR
part 1037. Each standard-setting part includes regulations describing
emission standards and related requirements and compliance provisions
for certifying engines or vehicles.
B. Light- and Medium-Duty Vehicle GHG Program
This subpart provides background on the EPA's light-duty and
medium-duty vehicle GHG emission programs. In general, through a series
of rulemakings beginning with Model Year 2010 for light-duty vehicles
and Model Year 2014 for medium-duty vehicles, the EPA increased the
stringency of the GHG standards for these vehicles over time, in
particular the CO2 standard. Section VI.A.2 of this preamble
describes the proposed changes to the light-duty and medium-duty
vehicle GHG regulations.
1. Background on the Light- and Medium-Duty Vehicle GHG Program
In 2010, the EPA relied on the Endangerment Finding to adopt the
first GHG emission standards for passenger cars and light trucks for
MYs 2012 through 2016 in a joint rulemaking with NHTSA.\119\ In 2012,
the EPA and NHTSA adopted another set of GHG standards (issued by EPA)
and fuel economy standards (issued by NHTSA) for passenger cars and
light trucks for MYs 2017 and later in a joint rulemaking.\120\ In
2020, the EPA and NHTSA revised the standards that had previously been
adopted and extended them for MYs 2021 through 2026.\121\ In 2021, we
further revised GHG standards for passenger cars and light trucks for
MYs 2023 through 2026.\122\ For medium-duty vehicles, we initially
adopted GHG standards as part of the Phase 1 and Phase 2 heavy-duty GHG
standards, as described in section VI.B.1 of this preamble. In 2024, we
adopted new standards for passenger cars, light trucks, and medium-duty
vehicles starting in MY 2027, effectively combining standards that had
previously been maintained separately.\123\
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\119\ 75 FR 25324 (May 7, 2010).
\120\ 77 FR 62624 (Oct. 15, 2012).
\121\ 85 FR 24174 (Apr. 30, 2020).
\122\ 86 FR 74434 (Dec. 30, 2021).
\123\ 89 FR 27842 (Apr. 18, 2024).
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The EPA has also taken various actions to comply with statutory
obligations under EPCA and EISA. Enacted in 1975, EPCA requires NHTSA
to establish a regulatory program for motor vehicle fuel economy (now
known as CAFE standards) and requires the EPA to establish measurement
procedures, data collection procedures, and rules for calculating
average fuel economy values in support of NHTSA's CAFE standards. In
2007, Congress amended EPCA by enacting EISA, which required continuing
increases in the stringency of CAFE standards for passenger cars and
light trucks through MY 2020. EISA also authorized new fuel consumption
standards for medium-duty vehicles and heavy-duty engines and
vehicles.\124\ Those standards, and the EPA's heavy-duty engine and
vehicle GHG programs, are detailed in section VI.B of this preamble.
---------------------------------------------------------------------------
\124\ 49 U.S.C. 32902(k).
---------------------------------------------------------------------------
To comply with EPCA and EISA, the EPA has adopted regulations for
fuel economy measurements, calculations, and reporting under 40 CFR
part 600. The regulation at 40 CFR part 600 now includes additional
provisions for measuring, calculating, and reporting fuel consumption
values for medium-duty vehicles. This regulatory structure was designed
to maximize efficiency within the Federal government and minimize the
burden on the engine and vehicle manufacturers by centralizing data
submission. We share information with NHTSA as needed to support
implementation of NHTSA's fuel economy and consumption standards.
2. Proposed Changes to the Light- and Medium-Duty Vehicle GHG
Regulations
The EPA's light-duty and medium-duty vehicle emission regulations
are spread across three CFR parts. 40 CFR part 85 includes various
general compliance provisions for both criteria pollutant and GHG
emissions. Many of those provisions apply equally to highway
motorcycles. 40 CFR part 86 includes emission standards and
certification provisions for both criteria pollutant and GHG emissions.
40 CFR part 600 includes measurement and reporting procedures related
to fuel economy and GHG standards and to fuel economy labeling.
In the following subsections, we describe our proposed removal and
amendment of specific portions of each of these regulatory parts. In
general, the approach taken in this proposal is to remove the MY 2012
and later GHG emission standards for passenger cars and light trucks
and the MY 2014 and later GHG emission standards for medium-duty
vehicles. We also propose to remove the testing and reporting
requirements associated with the GHG emission standards. In keeping
with our obligations under EPCA, as noted in section VI.A.1 of this
preamble, we are not proposing to remove the testing and reporting
requirements related to CAFE standards for passenger cars and light
trucks and are not reopening those requirements. We request comment on
the proposed regulatory changes and whether additional changes should
be considered.
[[Page 36316]]
a. 40 CFR Part 85--Compliance Provisions for Light- and Medium-Duty
Vehicles
In general, we propose to amend 40 CFR part 85 to remove all
references to GHG emission standards and related provisions while
retaining provisions that support our criteria pollutant emission
program. In this subsection, we describe several proposed amendments
that are necessary to remove GHG-related provisions from 40 CFR part 85
while ensuring that criteria pollutant emission standards are not
substantively impacted. Table 1 provides a summary of the proposed
amendments to 40 CFR part 85.
Table 1--Summary of Proposed Changes to Light-Duty and Medium-Duty
Highway Engine Regulations Under 40 CFR Part 85
------------------------------------------------------------------------
40 CFR part 85 Sections proposed to amend
------------------------------------------------------------------------
Subpart F--Exemption of Clean Alternative 85.525.
Fuel Conversions From Tampering
Prohibition.
Subpart P--Importation of Motor Vehicles 85.1515.
and Motor Vehicle Engines.
Subpart S--Recall Regulations.............. 85.1803, 85.1805.
Subpart T--Emission Defect Reporting 85.1902.
Requirements.
Subpart V--Warranty Regulations and 85.2103.
Voluntary Aftermarket Part Certification
Program.
------------------------------------------------------------------------
The regulations at 40 CFR part 85, subpart F, provide an exemption
from the general tampering prohibition for clean alternative fuel
conversions. Specifically, the regulations describe how anyone
modifying an in-use vehicle to run a different fuel can demonstrate
that the fuel conversion maintains a level of emission control that
qualifies them for an exemption from the tampering prohibition. This
exemption generally allows for the modifying of vehicles already
certified to emission standards in a way that does not cause the
modified vehicle to exceed the emission standards that apply for the
certified vehicle. The demonstration applies for both criteria and GHG
emissions. We are proposing to revise 40 CFR 85.525 by removing the
requirement to demonstrate compliance with GHG emissions. Program
requirements related to criteria exhaust, evaporative, and refueling
emissions and onboard diagnostics would remain unchanged.
The regulation at 40 CFR 85.1515 describes the standards that apply
for Independent Commercial Importers in their practice of importing
used vehicles. We are proposing only to remove text disallowing
generation and use of GHG emission credits. We note further that the
regulation requires Independent Commercial Importers to meet all the
standards that apply under 40 CFR part 86. With the proposed changes
described in this action, the removal of GHG standards from 40 CFR part
86, subpart S, would apply equally to imported vehicles. Imported
vehicles would continue to be subject to criteria exhaust, evaporative,
and refueling emission standards and requirements for onboard
diagnostics as specified in 40 CFR part 86, subpart S.
We are proposing to revise the recall-related instructions for
remedial plans and consumer notification in 40 CFR 85.1803 and 85.1805
to remove a reference to 40 CFR 86.1865(j)(3), which we are proposing
to remove in this action. The referenced paragraph relates to recall
provisions for vehicles that do not comply with GHG standards. We are
also proposing to revise definitions of ``Emission-related defect'' and
``Voluntary emissions recall'' in 40 CFR 85.1902 where those
definitions describe how manufacturers must report GHG-related defects
differently than defects related to criteria pollutant emission
standards. Finally, we are proposing to amend the warranty provisions
for specified major emission control components in 40 CFR 85.2103 by
removing the reference to batteries serving as a Renewable Energy
Storage System for electric vehicles and plug-in hybrid electric
vehicles, along with all components needed to charge the system, store
energy, and transmit power to move the vehicle. We would continue to
apply the basic emission-related warranty requirement for a period of
two years or 24,000 miles where such batteries qualify as an emission-
related component.
b. 40 CFR Part 86--Emission Standards and Certification Requirements
for Light- and Medium-Duty Vehicles
In general, we propose to amend 40 CFR part 86 to remove all GHG
emission standards, references to such standards, and related
provisions while retaining provisions that support our criteria
pollutant emission program. In this subsection, we describe several
proposed amendments that are necessary to remove GHG-related provisions
from 40 CFR part 86 while ensuring that criteria pollutant emission
standards are not substantively impacted. Table 2 provides a summary of
the regulations we propose either to remove or to amend in 40 CFR part
86.
Table 2--Summary of Proposed Changes to Light-Duty and Medium-Duty
Highway Engine Regulations Under 40 CFR Part 86
------------------------------------------------------------------------
Sections proposed Sections proposed
40 CFR part 86 to remove to amend
------------------------------------------------------------------------
86.1.
Subpart S--General Compliance 86.1815-27, 86.1801-12,
Provisions for Control of Air 86.1818-12, 86.1803-01,
Pollution From New and In-Use 86.1819-14, 86.1805-12,
Light-Duty Vehicles, Light-Duty 86.1865-12, 86.1805-17,
Trucks, and Heavy-Duty Vehicles. 86.1866-12, 86.1807-01,
86.1867-12, 86.1809-12,
86.1870-12. 86.1810-09,
86.1810-17,
86.1811-17,
86.1811-27,
86.1816-18,
86.1822-01,
86.1823-08,
86.1827-01,
86.1828-01,
86.1829-15,
86.1830-01,
86.1835-01,
86.1838-01,
86.1839-01,
86.1841-01,
86.1844-01,
86.1845-04,
86.1846-01,
86.1848-10,
86.1854-12,
86.1861-17,
86.1868-12,
86.1869-12.
------------------------------------------------------------------------
[[Page 36317]]
We are proposing to amend the list of reference documents in 40 CFR
86.1 by removing documents that are referenced only in regulations that
we are proposing to remove.
We are proposing to amend the applicability statements in 40 CFR
86.1801-12 by removing references to GHG standards and related
compliance provisions. We are also proposing to remove the instruction
related to work factor for vehicles above 14,000 pounds gross vehicle
weight rating (GVWR) at 40 CFR 86.1801-12(a)(3) since that is
meaningful only in the context of GHG standards. We adopted the work-
factor provision in a 2016 final rule as a means of limiting the extent
to which manufacturers would certify those larger heavy-duty vehicles
in test groups along with chassis-certified medium-duty vehicles.\125\
Removing the instruction to calculate GHG standards based on a work
factor appropriate for medium-duty vehicles, without other compensating
changes, could lead to a greater number of heavy-duty vehicles
certified as medium-duty vehicles. The work-factor provision was
adopted as a means of addressing competing concerns from different
manufacturers. As a result, we are proposing to limit the use of this
provision to heavy-duty vehicles with a maximum value of 19,500 pounds
GVWR. We believe this limitation is the best way to maintain a
consistent approach for certifying affected vehicles.
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\125\ 81 FR 73478 (Oct. 25, 2016).
---------------------------------------------------------------------------
We are proposing to amend the definitions in 40 CFR 86.1803-01 by
removing several defined terms that are used only in regulatory
provisions that we are proposing to remove. This includes proposing to
remove the definition of ``configuration''; while this definition is no
longer needed, we are proposing to retain the slightly different
definition of ``vehicle configuration,'' since that definition is
needed to support standards related to criteria pollutants. We are
accordingly proposing to amend several references across 40 CFR part
86, subpart S, to change from a generic reference to ``configuration''
and replace it with the specific reference to ``vehicle
configuration.'' We are also proposing to amend 40 CFR 86.1803-01 by
adding a definition for ``work factor'' that is consistent with the
definition that is embedded in 40 CFR 86.1819-14. We adopted the
definition of ``work factor'' in 40 CFR 86.1819-14 primarily as a means
of accounting for specific vehicle characteristics in establishing GHG
emission standards for medium-duty vehicles. We are proposing to remove
all of 40 CFR 86.1819-14 as described below. However, we are keeping
the definition of work factor to support the definition of ``medium-
duty passenger vehicle,'' which relies on the work factor concept to
categorize vehicles for applying criteria pollutant emission standards.
We are proposing to amend 40 CFR 86.1803-01 and 86.1809-12 by
removing references to the air conditioning efficiency test as part of
the consideration for determining what is a defeat device. We are
proposing to eliminate the air conditioning efficiency test from the
EPA certification program because it was only used to generate GHG
credits. Note that we are not proposing in this NPRM to remove the air
conditioning efficiency credit provisions and measurement procedures
from 40 CFR 86.1868-12 and 1066.845, which are used by manufacturers
for compliance with fuel economy standards as described in 40 CFR
600.510(c)(3).
We are proposing to amend useful life specifications in 40 CFR
86.1805-12 and 86.1805-17 by removing references to useful life for GHG
standards. Useful life for all criteria exhaust, evaporative, and
refueling emission standards and onboard diagnostics would remain
unchanged.
We are proposing to amend labeling requirements in 40 CFR 86.1807-
01 by removing the requirement for battery electric vehicles and plug-
in hybrid electric vehicles to identify monitor family and battery
durability family on the vehicle emission control information label. We
are proposing to remove the battery monitoring and battery durability
requirements in 40 CFR 86.1815-27 and therefore no longer to include
this family information as part of the certification process.
We are proposing to amend 40 CFR 86.1810-09(f)(2) by removing
references to GHG emission standards. Manufacturers must continue to
comply with altitude-related demonstration requirements for vehicles
subject to the cold temperature standards for nonmethane hydrocarbon
emissions.
We are proposing to amend 40 CFR 86.1810-17(j) by removing
references to GHG emission standards. Small-volume manufacturers that
modify a vehicle already certified by a different company must continue
to meet other requirements as specified, such as those related to
criteria exhaust, evaporative, and refueling emissions and onboard
diagnostics.
We are proposing to amend 40 CFR 86.1811-17, 86.1811-27, and
86.1816-18 by removing references to GHG emission standards. We are not
otherwise proposing to change these sections, which establish criteria
exhaust emission standards for light-duty and medium-duty vehicles.
We are proposing to remove 40 CFR 86.1815. We adopted this section
to establish battery monitoring and battery durability requirements for
battery electric vehicles and plug-in hybrid electric vehicles. Those
battery-related requirements were adopted as part of the overall
program for controlling GHG emissions. Since the earliest battery
monitoring and battery durability requirements were scheduled to start
in MY 2027, removing those requirements involves no immediate
transition to discontinue compliance for certified vehicles.
We are proposing to remove 40 CFR 86.1818-12 and 86.1819-14. These
sections describe the GHG standards and implementing provisions for MY
2010 and later light-duty vehicles and for MY 2014 and later medium-
duty vehicles. We propose to discontinue the requirement to demonstrate
compliance with these GHG standards and further propose that this
discontinuation would apply as of the effective date of the final rule.
Manufacturers need not amend existing certificates for ongoing
production for the current model year. Manufacturers would in any case
not need to submit credit reports at the end of the current model year
to demonstrate compliance with the fleet average CO2
standards.
We are proposing to amend test group specifications in 40 CFR
86.1823-08 by removing durability demonstration requirements related to
GHG emission standards.
We are proposing to amend the provisions for establishing test
groups in 40 CFR 86.1827-01 by removing the reference to CO2
emission standards.
We are proposing to amend testing specifications in 40 CFR 86.1829-
15 by removing references to GHG emission standards, except where
needed to account for emission measurements related to fuel economy
labeling. We are also proposing to change the nomenclature for the
reference brake-specific CO2 emission rate needed to perform
calculations related to in-use testing for engines certified under 40
CFR 1036.635 for use in vehicles with high towing capacity.
We are proposing to amend the compliance provisions 40 CFR 86.1835-
01, 86.1838-01, 86.1841-01, 86.1848-10, and 86.1854-12 by removing
references to GHG emission standards.
We are proposing to amend carryover testing provisions in 40 CFR
86.1839-01 by removing references to accuracy requirements for battery
monitoring for
[[Page 36318]]
electric vehicles and plug-in hybrid electric vehicles.
We are proposing to amend instructions for the application for
certification in 40 CFR 86.1844-01 by removing references to
refrigerant leakage rates and GHG emission standards.
We are proposing to amend in-use testing requirements in 40 CFR
86.1845-04 and 86.1846-01 by removing references to testing GHG
emissions and testing related to battery monitor accuracy and battery
durability for electric vehicles and plug-in hybrid electric vehicles.
We are also proposing to amend 40 CFR 86.1845-04 by changing the
nomenclature for the reference brake-specific CO2 emission
rate needed to perform calculations related to in-use testing for
engines certified under 40 CFR 1036.635 for use in vehicles with high
towing capacity.
We are proposing to amend the credit provisions for criteria
exhaust and evaporative emissions in 40 CFR 86.1861-17 by referencing
the credit provisions in 40 CFR part 1036, subpart H, instead of 40 CFR
part 1037, subpart H. We are proposing to remove the credit provisions
in 40 CFR part 1037, subpart H, in this rule because they are needed
only in relation to the GHG standards in 40 CFR part 1037, which we are
proposing to remove in this rule. The referenced credit provisions in
40 CFR part 1037, subpart H, are equivalent to the analogous credit
provisions in 40 CFR part 1036, subpart H. We are also proposing to
amend 40 CFR 86.1861-17 by removing a reference to 40 CFR
86.1865(j)(3), which we are proposing to remove in this action.
We are proposing to remove 40 CFR 86.1865-12. This section
describes the emission credit provisions related to the fleet average
GHG standards. See the discussion related to 40 CFR 86.1818-12 and
86.1819-14 for the transition to discontinued GHG standards for the
model year currently in production for the year when the final rule is
effective. More specifically, we are proposing no longer to recognize
manufacturers' positive or negative GHG credit balances as of the
effective date of the final rule. Note also that we are proposing to
remove 40 CFR 86.1865-12(j)(3), which describes recall provisions for
vehicles that do not comply with GHG standards. We recognize that a
credit-based approach to recall is no longer appropriate without a GHG
credit program. Accordingly, we are proposing to remove the provisions
describing a credit-based remedy for noncompliance that does not
involve a vehicle defect that can be repaired to bring vehicles into
compliance with standards.
We are proposing to remove 40 CFR 86.1866-12, 86.1867-12, and
86.1867-31. These sections describe GHG credit programs for advanced
technology and air conditioning leakage that serve only in relation to
the GHG standards that we are proposing to remove in this rule.
We are proposing to amend the credit provisions for air
conditioning efficiency and for off-cycle technologies in 40 CFR
86.1868-12 and 86.1869-12 by removing references to the fleet average
GHG standards and adjusting the description to clarify that these
credit provisions continue to serve as inputs for calculating fuel
consumption improvement values and average fuel economy for light-duty
program vehicles under 40 CFR 600.510. The 2024 final rule included new
standards for light-duty program vehicles and several changes related
to these credit programs, and we are not reopening those
decisions.\126\ First, we adopted a change for both air conditioning
efficiency credits and off-cycle credits to not allow vehicles without
engines to generate those credits starting in model year 2027. Second,
we created a schedule to phase down off-cycle credits for vehicles with
engines by establishing a declining value of the cap on off-cycle
credits through model year 2032, with off-cycle credits fully
discontinued for all vehicles starting in model year 2033. Third, we
removed the option for manufacturers to generate off-cycle credits
according to the provisions of 40 CFR 86.1869-12(c) and (d) starting in
model year 2027.
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\126\ 89 FR 27842 (Apr. 18, 2024).
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We are proposing to remove 40 CFR 86.1870-12. This section
describes a GHG credit program for full-size pickup trucks with hybrid
technology. Those GHG credits were also used for calculating fuel
consumption improvement values and average fuel economy for light-duty
program vehicles under 40 CFR 600.510. However, we amended those credit
provisions in the 2021 final rule to establish model year 2024 as the
last year that manufacturers could generate those credits.\127\ Because
those credits are already discontinued for purposes of demonstrating
compliance with EPA emission standards, manufacturers can no longer use
those provisions to create fuel consumption improvement values under 40
CFR part 600.
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\127\ 86 FR 74434 (Dec. 30, 2021).
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c. 40 CFR Part 600--Requirements Related to Fuel Economy for Light- and
Medium-Duty Vehicles
In general, we propose to amend 40 CFR part 600 to remove all
references to GHG emission standards and related provisions while
retaining provisions that support compliance with CAFE standards and
fuel economy labeling for passenger cars and light trucks. In the
remainder of this subsection, we describe several proposed amendments
that are needed to remove GHG-related provisions from 40 CFR part 600
without affecting provisions related to CAFE standards and fuel economy
labeling. Table 3 provides a summary of the regulations we propose
either to remove or to amend in 40 CFR part 600.
Table 3--Summary of Proposed Changes to Light-Duty and Medium-Duty
Highway Engine Regulations Under 40 CFR Part 600
------------------------------------------------------------------------
Sections proposed Sections proposed
40 CFR part 600 to remove to amend
------------------------------------------------------------------------
Subpart A--General Provisions... .................. 600.001, 600.002,
600.006, 600.007,
600.008, 600.010.
Subpart B--Fuel Economy and .................. 600.101, 600.111-
Exhaust Emission Test 08, 600.113-12,
Procedures. 600.114-12,
600.116-12,
600.117.
Subpart C--Procedures for .................. 600.206-12,
Calculating Fuel Economy and 600.207-12,
Carbon-related Exhaust Emission 600.210-12.
Values.
Subpart F--Procedures for 600.514-12........ 600.507-12,
Determining Manufacturer's 600.509-12,
Average Fuel Economy. 600.510-12,
600.512-12.
------------------------------------------------------------------------
[[Page 36319]]
We are proposing to amend the applicability statements in 40 CFR
600.001 by removing references to carbon-related exhaust emissions and
fleet average CO2 standards. We are also proposing to remove
the reference in 40 CFR 600.001(a) to medium-duty vehicles because we
are proposing to revise 40 CFR part 600 such that those vehicles would
no longer be subject to regulation under 40 CFR part 600. In contrast,
the testing provisions would remain to describe how passenger
automobiles and light trucks (including medium-duty passenger vehicles)
must meet fuel economy standards and how manufacturers must prepare
fuel economy labels.
We are proposing to amend the definitions in 40 CFR 600.002 by
removing the reference to fleet average CO2 standards. We
are also proposing to remove the portions of several definitions that
relate to medium-duty vehicles (also described as heavy-duty vehicles
in the regulation).
We are proposing to amend the definition of Medium-Duty Passenger
Vehicle (MDPVFE) for purposes of fuel economy testing and
reporting in 40 CFR 600.002 to align with the clarified definition
published by NHTSA at 49 CFR 523.2 (89 FR 52945, June 24, 2024).
Aligning these definitions is necessary to ensure EPA's test procedures
are properly applied to vehicles covered by fuel economy standards and
labeling requirements.
As described for 40 CFR 86.1803-01, we are proposing to amend
several references across 40 CFR part 600 to change from a generic
reference to ``configuration'' and replace it with the specific
reference to ``vehicle configuration.''
We are proposing to amend the information requirements in 40 CFR
600.006 through 600.010 by removing references to carbon-related
exhaust emissions, GHG emission standards, and reporting GHG-related
information generally.
We are proposing to amend the testing overview in 40 CFR 600.101
and 600.111-08 by removing references to carbon-related exhaust
emissions and fleet average CO2 emissions.
We are proposing to amend the emission calculations in 40 CFR
600.113-12 by removing references to carbon-related exhaust emissions
and other GHG emissions.
We are proposing to amend the interim testing provisions in 40 CFR
600.117 by removing paragraph (a)(5) since we are proposing to
discontinue GHG testing with in-use vehicles under 40 CFR 86.1845-04.
We are also proposing to revise paragraphs (a)(6) and (b) to clarify
that manufacturers do not adjust measured fuel economy values to
account for fuel effects, whether they test with E0 or E10 gasoline.
We are proposing to amend the testing, calculation, and reporting
specifications in 40 CFR 600.116-12, 600.507-12, 600.509-12, and
600.510-12 by removing references to carbon-related exhaust emissions.
We note that calculations related to off-cycle credits in 40 CFR
600.510(c)(3)(ii) continue to rely on carbon-related exhaust emissions
as specified in 40 CFR 86.1869-12.
We are proposing to amend the reporting requirements in 40 CFR
600.512-12 by removing references to carbon-related exhaust emissions.
This includes amending 40 CFR 600.512-12(c)(5)(i) to explain that the
purpose for performing the calculations in 40 CFR 600.510-12(c)(3) is
to support credit calculations for fuel economy improvement factors,
rather than demonstrating compliance with the fleet average standard
for carbon-related exhaust emissions. We are proposing to move the
existing reporting requirement for emission credits related to fuel
consumption improvement values from 40 CFR 86.1865-12(l)(2)(iii), which
we are proposing to remove, to 40 CFR 600.512-12(c)(3) to preserve the
existing provisions needed for fuel economy reporting. We are also
proposing to remove the reporting requirements in 40 CFR 600.514-12,
which are solely related to GHG emissions.
C. Heavy-Duty Engine and Vehicle GHG Program
This subpart includes background on EPA's heavy-duty GHG emission
program and describes our proposed changes to the engine-based GHG
regulations and our proposed changes to the vehicle-based GHG
regulations.
1. Background on the Heavy-Duty Engine and Vehicle GHG Program
The EPA promulgated new GHG emission standards for heavy-duty
engines and vehicles in three separate rulemakings. In 2011, the EPA
established the first GHG standards for model year 2014 and later
heavy-duty engines and vehicles in an action titled ``Greenhouse Gas
Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty
Engines and Vehicles'' (HD GHG Phase 1).\128\ In 2016, the EPA set new
GHG standards for model year 2021 and later heavy-duty engines and
vehicles in an action titled ``Greenhouse Gas Emissions and Fuel
Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles--
Phase 2'' (HD GHG Phase 2).\129\ Most recently, in 2024, the EPA
finalized an action titled ``Greenhouse Gas Emissions Standards for
Heavy-Duty Vehicles--Phase 3'' (HD GHG Phase 3), which set new
CO2 emission standards for model year 2032 and later heavy-
duty vehicles that phase in starting as early MY 2027 for certain
vehicle categories.\130\ The phase-in revises MY 2027 GHG standards
that were established previously under the EPA's HD GHG Phase 2
rulemaking.\131\
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\128\ 76 FR 57106 (Sept. 15, 2011).
\129\ 81 FR 73478 (Oct. 25, 2016).
\130\ See 89 FR 29559-29561 (Apr. 22, 2024).
\131\ 89 FR 29440 (Apr. 22, 2024).
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The EPA and NHTSA jointly issued the HD GHG Phase 1 and HD GHG
Phase 2 rulemakings covering heavy-duty GHG emission and fuel
efficiency standards. The EPA set GHG emission standards under CAA
section 202(a), and NHTSA set fuel consumption standards under
EISA.\132\ The EPA and NHTSA programs are harmonized through MY 2026;
however, NHTSA has not adopted changes in fuel consumption standards
corresponding to the EPA's HD GHG Phase 3 standards. As a result, the
CO2 emission and fuel consumption standards currently
diverge in MY 2027 and later.
---------------------------------------------------------------------------
\132\ 49 U.S.C. 32902(k).
---------------------------------------------------------------------------
The EPA's regulations include the test procedures along with a
certification and compliance program, which is led by the EPA. As noted
previously, this regulatory structure was designed to maximize
efficiency within the Federal government and minimize the burden on the
engine and vehicle manufacturers by centralizing data submission.
Manufacturers submit data and information to the EPA and the EPA, in
turn, shares information with NHTSA as needed to support NHTSA's
implementation of its fuel consumption standards.\133\
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\133\ See 49 CFR 535.8, 1036.755, 1037.755.
---------------------------------------------------------------------------
2. Proposed Changes to the Heavy-Duty Engine and Vehicle GHG
Regulations
The EPA's heavy-duty engine and vehicle emission regulations are
contained in two standard-setting parts. 40 CFR part 1036 includes the
engine-based emissions regulations for both criteria pollutant and GHG
emissions.\134\ 40 CFR part 1037 includes the vehicle-based emission
regulations for criteria pollutant exhaust emissions,
[[Page 36320]]
evaporative and refueling emissions, and GHG emissions.
---------------------------------------------------------------------------
\134\ Note that heavy-duty engine manufacturers are subject to
criteria pollutant standards in 40 CFR part 86, subpart A, through
2026. In a recent rulemaking (88 FR 4296, Jan. 24, 2023), the EPA
migrated criteria pollutant regulations from 40 CFR part 86, subpart
A, to 40 CFR part 1036 with new requirements that apply to 2027 and
later heavy-duty engines. See 88 FR 4326.
---------------------------------------------------------------------------
In the following subsections, we describe our proposed removal and
amendment of specific portions of each of these regulatory parts. In
general, the approach taken in this proposal is to remove the MY 2014
and later heavy-duty GHG emission standards promulgated in HD GHG Phase
1, Phase 2, and Phase 3, collectively, along with the testing and
reporting requirements associated with the GHG emission standards. We
request comment on the proposed regulatory changes and whether
additional changes are necessary to remove GHG regulations.
a. 40 CFR Part 1036--Emission Standards and Compliance Provisions for
Heavy-Duty Engines
40 CFR part 1036 contains regulations related to the final rule
titled ``Control of Emissions from New and In-Use Heavy-Duty Highway
Engines,'' including emission standards and compliance provisions for
criteria pollutant emissions, evaporative and refueling emissions, and
GHG exhaust emissions (i.e., CO2, N2O, and
methane). 40 CFR part 1036 is divided into nine subparts with three
appendices. Subpart A defines the applicability of part 1036 and gives
an overview of regulatory requirements. Subpart B describes the
emission standards and other requirements that must be met to certify
engines under this part. Subpart C describes how to apply for a
certificate of conformity for heavy-duty engines. Subpart D addresses
testing of production engines and hybrid powertrains. Subpart E
addresses in-use testing, while Subpart F describes how to test engines
to demonstrate compliance with the criteria pollutant and GHG emission
standards. Subpart G describes requirements, prohibitions, and other
provisions that apply to engine manufacturers, vehicle manufacturers,
owners, operators, rebuilders, and all others. Subpart H describes how
manufacturers can optionally generate, bank, trade, and use emission
credits to certify heavy-duty engines. Subpart I includes definitions
and other reference material. Appendix A includes a summary of previous
emissions standards. Appendix B includes the transient duty cycles.
Appendix C includes engine fuel maps used in the certification of
specific vehicles to meet the heavy-duty vehicle CO2
emission standards.
This subsection includes an overview of the regulations related to
the heavy-duty engine program we propose to remove or revise. In
general, we propose to amend 40 CFR part 1036 to remove all GHG
emission standards, references to such standards, and related
provisions; however, most of 40 CFR part 1036 is retained for EPA's
heavy-duty engine criteria pollutant emission program. In this
subsection, we describe the proposed amendments to remove GHG-related
provisions from 40 CFR part 1036, which include some amendments needed
to retain, without reopening, the efficacy of the criteria pollutant
emission standards. Table 4 provides a summary of the regulations we
propose either to remove or to amend in 40 CFR part 1036.
Table 4--Summary of Proposed Changes to Heavy-Duty Highway Engine
Regulations Under 40 CFR Part 1036
------------------------------------------------------------------------
Sections proposed Sections proposed
40 CFR part 1036 to remove to amend
------------------------------------------------------------------------
Subpart A--Overview and .................. 1036.1, 1036.5,
Applicability. 1036.15.
Subpart B--Emission Standards 1036.108.......... 1036.101,
and Related Requirements. 1036.115,
1036.130,
1036.135,
1036.150.
Subpart C--Certifying Engine 1036.241.......... 1036.205,
Families. 1036.225,
1036.230,
1036.231,\a\
1036.235,
1036.245.
Subpart D--Testing Production .................. 1036.301.
Engines and Hybrid Powertrains.
Subpart E--In-Use Testing....... .................. 1036.415.
Subpart F--Test Procedures...... 1036.505, 1036.501,
1036.535, 1036.510,
1036.540, 1036.512,
1036.543, 1036.514,
1036.550. 1036.520,
1036.530,
1036.545,
1036.580.
Subpart G--Special Compliance 1036.610, 1036.605.\b\
Provisions. 1036.615,
1036.620,
1036.625,
1036.630,
1036.635.
Subpart H--Averaging, Banking, 1036.745, 1036.755 1036.701,
and Trading for Certification. 1036.705,
1036.710,
1036.720,
1036.725,
1036.730,
1036.740,
1036.750.
Subpart I--Definitions and Other .................. 1036.801,
Reference Information. 1036.805,
1036.810,
1036.815.
Appendices...................... Appendix C........
------------------------------------------------------------------------
\a\ We are proposing to move 40 CFR 1037.231 to a new 40 CFR 1036.231.
\b\ We are proposing similar revisions in 40 CFR 86.007-11(g) and 86.008-
10(g) for model year 2026 and earlier engines for specialty vehicles.
Within 40 CFR part 1036, subpart B, we propose to remove 40 CFR
1036.108, which includes the GHG emission standards for CO2,
N2O, and methane. We also propose to remove several
paragraphs from 40 CFR 1036.150 that describe interim provisions
related to the heavy-duty engine or vehicle GHG programs. We propose to
remove and reserve 40 CFR 1036.150(b), (d), (e), (g)-(j), (l)-(n), (p)-
(s), and (w) and otherwise to retain the existing section numbering. We
propose to remove 40 CFR 1036.150(aa) at the end of the section.
In 40 CFR part 1036, subpart C, we propose to remove 40 CFR
1036.230(f) and (g), which describe how manufacturers divide their
product lines into engine families for certifying to the GHG emission
standards. We propose several revisions in 40 CFR 1036.235 to remove
GHG emission testing requirements. In 40 CFR 1036.235(a), we propose to
migrate text from 40 CFR 1037.235(a) that provides direction on how
manufacturers select the test powertrain to replace GHG-related testing
requirements in 40 CFR 1036.235(a)(2). We propose to remove in its
entirety 40 CFR 1036.241, which describes how to demonstrate compliance
with the heavy-duty engine GHG emission standards. In 40 CFR 1036.245,
existing provisions allow manufacturers to use vehicle-based duty
cycles for engine service accumulation in the laboratory to determine
deterioration factors. As described in section VI.C.2.b of this
preamble, we are proposing to remove the referenced vehicle-based duty
cycles from 40 CFR part 1037, so we are proposing to revise 40 CFR
1036.245(c)(3)(ii) to allow manufacturers to request approval of a
[[Page 36321]]
different test sequence, without requiring specific duty cycles.
Also in 40 CFR part 1036, subpart C, we propose to migrate the
provisions that relate to powertrain families from the vehicle
standard-setting part in 40 CFR 1037.231 to the engine standard-setting
part as a new 40 CFR 1036.231 with proposed revisions described in this
section. In a previous rule (89 FR 29616), we migrated the powertrain
test procedure from the heavy-duty vehicle procedures (formerly 40 CFR
1037.550) to the heavy-duty engine procedures in 40 CFR 1036.545
because we expected powertrain testing to be primarily used by engine
manufacturers in certifying engines to criteria pollutant standards or
in place of engine-based procedures for GHG standards. Similarly, we
are proposing to migrate the related provisions manufacturers would use
to divide their product line into powertrain families. In general, we
propose to migrate the text from the vehicle program in 40 CFR 1037.231
to a newly created section in the engine program under 40 CFR 1036.231.
We propose to modify the text previously under 40 CFR 1037.231(b)(1),
such that the new 40 CFR 1036.231(b)(1) would no longer require
powertrains to share the same engine families described in 40 CFR
1036.230 but would require the engine share the same design aspects
specified in 40 CFR 1036.230. Since a manufacturer may choose to
certify the whole powertrain to the standards in 40 CFR part 1036,
there would only be a powertrain family, not a certified engine family
that contains just the engine. Similarly, and consistent with our
approach for defining engine families in 40 CFR 1036.230, we see no
need to limit the powertrain family based on the vehicle service class
the powertrain goes into and propose not to migrate the existing 40 CFR
1037.231(b)(2) that requires powertrain families to share vehicle
service class groupings. We are also proposing not to migrate ``energy
capacity'' as an example attribute in the proposed new 40 CFR
1036.231(b)(10), since it is not needed for the criteria pollutant
standards. Similarly, we are proposing not to migrate existing 40 CFR
1037.231(b)(11) since rated output of hybrid mechanical power
technology is also not needed for a criteria pollutant family
definition.
In 40 CFR part 1036, subpart D, we propose to revise 40 CFR
1036.301 to remove paragraphs (a) through (d) describing how the EPA
would conduct selective enforcement audits related to heavy-duty
CO2 engine emissions. We propose to revise the existing
statement that selective enforcement audits apply for engines as
specified in 40 CFR part 1068, subpart E, by adding that they apply for
powertrains, consistent with 40 CFR 1036.301(c) which we are proposing
to remove.
As previously noted, we are retaining and not reopening the in-use
testing procedures in 40 CFR part 1036, subpart E, which apply for the
criteria pollutant emission standards. More specifically, within the
in-use test procedures, we are retaining references to measuring
CO2 for use in required chemical balance test procedures and
to calculate the criteria pollutant emissions values for in-use
testing. Also, in 40 CFR 1036.415(g), we continue to require that
manufacturers override any adjustable idle-reduction features on
vehicles used for in-use testing; however, we propose to revise the
text to include a more general statement describing what it means to be
adjustable.
In 40 CFR part 1036, subpart F, we propose to remove test
procedures related to developing engine data to support heavy-duty
vehicle GHG emissions certification, which include 40 CFR 1036.505,
1036.535, 1036.540, 1036.543, and 1036.550. Relatedly, we propose to
remove the fuel map duty cycle in Appendix C to part 1036. In 40 CFR
1036.510, we propose several revisions to paragraph (b), including
replacing a reference to 40 CFR 1036.540(c)(2) with a new table that
provides the gear ratios based on engine service class from 40 CFR
1036.540. We also propose to remove and reserve 40 CFR 1036.510(e) and
1036.512(e), which describe how to determine GHG emissions for plug-in
hybrid powertrains using the heavy-duty engine Federal Test Procedure
(FTP) and engine Supplemental Emissions Test (SET) and duty cycles,
respectively. In 40 CFR 1036.530(e), we are retaining and not reopening
the requirement that manufacturers measure CO2 emissions for
in-use testing, but we propose to revise the related variable
eCO2FTPFCL to remove reference to ``family certification
limit (FCL)'' that would no longer apply. The proposed new variable,
eCO2FTP, would represent the engine's brake-specific
CO2 over the FTP or SET duty cycle. Relatedly, we are
proposing to replace references to eCO2FTPFCL with
eCO2FTP throughout 40 CFR parts 1036 and 1037.
Powertrain testing, also described in 40 CFR part 1036, subpart F,
is an option that manufacturers may use for certifying hybrid
powertrains to the engine criteria pollutant standards in 40 CFR
1036.104 and the GHG emission standards in 40 CFR 1036.108. The
powertrain test procedure in 40 CFR 1036.545 describes testing a
powertrain that includes an engine coupled with a transmission, drive
axle, and hybrid components, or a subset of these components. We are
retaining without reopening most of 40 CFR 1036.545 related to the
powertrain testing for criteria pollutants, but we propose to remove
the portions related to the GHG program and revise several paragraphs
to account for the removed GHG content. Throughout 40 CFR 1036.545, we
propose to remove existing requirements to create inputs for EPA's
Greenhouse gas Emission Model (GEM) tool that manufacturers use for
compliance with the CO2 standards. We also propose to remove
references to the use of utility factors, vehicle configurations, and
vehicle-based duty cycles and test procedures. In 40 CFR 1036.545(b),
(d), and (j) we propose to replace 40 CFR part 1037 references with
relevant text from the procedures. We also propose to remove paragraph
(p) which describes the procedure to determine usable battery energy
for plug-in hybrid powertrains.
As noted in 40 CFR 1036.545(a), powertrain testing depends on
vehicle and component models to test the powertrain using the engine-
based duty cycles and the existing 40 CFR 1036.545(a), (f), and (g),
and allow manufacturers to use the hardware-in-the-loop (HIL) model
included in GEM. As described in section VI.C.2.b of this preamble, we
propose to remove GHG vehicle testing requirements for most vehicles,
including any requirements to use GEM to demonstrate compliance.
However, we propose to retain the use of the HIL model within GEM Phase
2, Version 4.0 for the powertrain test procedure.\135\
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\135\ GEM Phase 2, Version 4.0 is incorporated by reference in
40 CFR 1036.545. See also 40 CFR 1036.810.
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In 40 CFR part 1036, subpart G, we propose revisions to 40 CFR
1037.605 to remove the GHG requirements for engines installed in
specialty vehicles and are proposing to make similar changes in 40 CFR
86.007-11(g) and 86.008-10(g) for model year 2026 and earlier specialty
vehicle engines. We propose to remove 40 CFR 1036.610 through 1036.630,
which include compliance provisions related to heavy-duty engine GHG
emissions compliance. We propose also to remove 40 CFR 1036.635, which
describes how manufacturers that certify engines for use in high-gross
combined vehicle weight (GCWR) medium-duty vehicles under 40 CFR part
1036 could comply with GHG standards under 40 CFR part 86, subpart S.
With no need to describe the GHG-related flexibilities in 40 CFR
1036.635, the existing applicability
[[Page 36322]]
provisions in 40 CFR 1036.1 and 1036.5 already cover the certification
provisions for high-GCWR vehicles as they relate to criteria
pollutants. Specifically, 40 CFR 1036.1 sets up the default of applying
the standards and certification requirements from 40 CFR part 1036 to
all engines installed in heavy-duty vehicles (generally vehicles above
8,500 pounds GVWR), while 40 CFR 1036.5 allows manufacturers to certify
medium-duty vehicles to the chassis-based program as described in 40
CFR 86.1801-12. We are proposing to make minor changes to 40 CFR
1036.5(a) to differentiate more clearly the certification requirements
for medium-duty vehicles from those for heavy-duty engines.
In 40 CFR part 1036, subpart H, we propose to remove 40 CFR
1036.745, which describes CO2 emission credit deficits.
In 40 CFR part 1036, subpart I, we propose to remove GHG-specific
symbols, abbreviations, and acronyms from 40 CFR 1036.805, and propose
to remove materials from 40 CFR 1036.810 that are only incorporated by
reference in the test procedures we propose to remove. In 40 CFR
1036.801, we propose to remove several GHG-specific definitions, and
are moving transmission- and other powertrain-related definitions from
the heavy-duty vehicle definitions in 40 CFR 1037.801 to the engine
definitions in 40 CFR 1036.801, so they can be available to engine
manufacturers using the powertrain test procedures in 40 CFR 1036.545.
b. 40 CFR Part 1037--Emission Standards and Compliance Provisions for
Heavy-Duty Vehicles
40 CFR part 1037 contains regulations related to the final rule
titled ``Control of Emissions from New Heavy-Duty Motor Vehicles,''
including GHG emission standards for CO2 and HFC, criteria
pollutant emission standards that apply for all heavy-duty vehicles,
and evaporative and refueling emission standards that apply for certain
heavy-duty vehicles. 40 CFR part 1037 is divided into nine subparts
with five appendices. Subpart A defines the applicability of part 1037
and gives an overview of regulatory requirements. Subpart B describes
the emission standards and other requirements that must be met to
certify vehicles under this part. Subpart C describes how to apply for
a certificate of conformity. Subpart D and E address testing of
production and in-use vehicles, respectively. Subpart F describes how
to test vehicles and perform emission modeling for vehicles subject to
the CO2 emission standards. Subpart G, along with 40 CFR
part 1068, describe requirements, prohibitions, and other provisions
that apply to manufacturers, owners, operators, rebuilders, and all
others. Subpart H describes how manufacturers can optionally generate
and use emission credits to certify vehicles. Subpart I includes
definitions and other reference material. Finally, Appendix A, B, and D
include test cycles, Appendix C presents emission control identifiers
for emissions labels, and Appendix E presents power take-off utility
factors.
This subsection includes an overview of the regulations related to
the heavy-duty vehicle program we propose to remove or revise. In
general, we propose to amend 40 CFR part 1037 to remove all GHG
emission standards, references to such standards, and related
provisions without revising or reopening provisions necessary to
support criteria pollutant standards, including evaporative and
refueling emissions standards. Below we describe the proposed
amendments to remove GHG-related provisions from 40 CFR part 1037,
which include some amendments needed to retain the efficacy of the
criteria pollutant emission standards. Table 5 provides a summary of
the regulations we propose either to remove or to amend in 40 CFR part
1037.
Table 5--Summary of Proposed Changes to Heavy-Duty Highway Vehicle
Regulations Under 40 CFR Part 1037
------------------------------------------------------------------------
Sections proposed Sections proposed
40 CFR part 1037 to remove to amend
------------------------------------------------------------------------
Subpart A--Overview and .................. 1037.5, 1037.10,
Applicability. 1037.15.
Subpart B--Emission Standards 1037.105, 1037.101,
and Related Requirements. 1037.106, 1037.102,
1037.140, 1037.115,
1037.150. 1037.120,
1037.125,
1037.135.
Subpart C--Certifying Vehicle 1037.231,\a\ 1037.201,
Families. 1037.232. 1037.205,
1037.225,
1037.230,
1037.235,
1037.250.
Subpart D--Testing Production 1037.301,
Vehicles and Engines. 1037.305,
1037.315,
1037.320.
Subpart E--In-Use Testing....... 1037.401..........
Subpart F--Test and Modeling 1037.501,
Procedures. 1037.510,
1037.520,
1037.525,
1037.527,
1037.528,
1037.530,
1037.532,
1037.534,
1037.540,
1037.551,
1037.555,
1037.560,
1037.565,
1037.570.
Subpart G--Special Compliance 1037.610, 1037.601,
Provisions. 1037.615, 1037.605,
1037.630, 1037.620,
1037.631, 1037.621,
1037.640, 1037.622,
1037.645, 1037.635.
1037.655,
1037.660,
1037.665,
1037.670.
Subpart H--Averaging, Banking, 1037.701,
and Trading for Certification. 1037.705,
1037.710,
1037.715,
1037.720,
1037.725,
1037.730,
1037.735,
1037.740,
1037.745,
1037.750,
1037.755.
Subpart I--Definitions and Other 1037.810.......... 1037.801,
Reference Information. 1037.825.
Appendices...................... Appendices A, B,
C, D, E.
------------------------------------------------------------------------
\a\ We are proposing to move 40 CFR 1037.231 to a new 40 CFR 1036.231.
In 40 CFR part 1037, subpart A, we are retaining and not proposing
to reopen the existing applicability of 40 CFR part 1037. Specifically,
as described in existing 40 CFR 1037.1, the part would continue to
apply for battery electric vehicles, fuel cell electric vehicles, and
vehicles fueled by conventional and alternative fuels.
Existing 40 CFR part 1037, subpart B, includes criteria pollutant
exhaust emission standards, evaporative and refueling emission
standards, and GHG emission standards that apply at the
[[Page 36323]]
vehicle level. In 40 CFR part 1037, subpart B, we propose to remove the
MY 2014 and later heavy-duty vehicle CO2 emission standards
promulgated in HD GHG Phase 1, Phase 2, and Phase 3. This includes the
vocational vehicle standards in 40 CFR 1037.105 and the tractor
standards in 40 CFR 1037.106. We also propose to amend 40 CFR 1037.115
to remove the HFC emission standards. We propose to amend 40 CFR
1037.120 to remove the emission control components related to heavy-
duty vehicle GHG-reducing technologies. We are retaining and not
proposing to reopen the requirement that the basic emission-related
warranty applies for fuel cell stacks and rechargeable energy storage
systems (RESS) as they continue to qualify as an emission-related
component related to criteria pollutant emission standards. Similarly,
we are retaining and not proposing to reopen the emission control
components covering a vehicle's evaporative and refueling emissions.
Also in Subpart B, we propose to remove 40 CFR 1037.140 and 1037.150,
which include the vehicle classifications and interim provisions
related directly to the heavy-duty vehicle GHG emission standards.
While we propose to remove GHG standards and related requirements,
we would retain without reopening criteria pollutant exhaust emission
standards in 40 CFR 1037.102 and the evaporative and refueling emission
standards in 40 CFR 1037.103. We propose to revise 40 CFR 1037.102(a)
to describe how vehicles can be deemed to meet the criteria pollutant
exhaust emission standards without testing under 40 CFR part 1037. As
proposed, vehicle manufacturers would continue to submit an application
for certification meeting the applicable requirements in 40 CFR
1037.205, affix an appropriate label to their vehicles as specified in
40 CFR 1037.135, and meet the applicable reporting and recordkeeping
requirements in 40 CFR 1037.250. Under this proposed approach, most
heavy-duty vehicles would be deemed to meet the criteria pollutant
exhaust emissions standards if manufacturers state in their
applications for certification that the installed engines are certified
to the standards of 40 CFR part 86 or 1036, as applicable. We similarly
propose specialty vehicles meeting the requirements in 40 CFR 1037.605
and heavy-duty glider vehicles meeting the requirements 40 CFR 1037.635
would also be deemed to meet the criteria pollutant exhaust emission
standards.\136\ Existing 40 CFR part 1037 includes other requirements
that would continue to apply for certain vehicles, and we propose to
revise 40 CFR 1037.102(a) to also refer to the requirements we are
retaining and not reopening for auxiliary power units (APUs) installed
on new tractors, now specified in proposed new 40 CFR 1037.102(c), and
for the vehicles subject to the existing evaporative and refueling
emission standards that apply as specified in 40 CFR 1037.103.
---------------------------------------------------------------------------
\136\ See the discussion of 40 CFR part 1037, subpart G, for the
revisions we propose related to the specialty vehicle and glider
vehicle provisions.
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In the HD GHG Phase 2 rulemaking, we adopted PM emission standards
that apply for APUs installed on new tractors.\137\ The APU
requirements are currently specified in 40 CFR 1037.106 with the other
tractor standards, including the GHG emission standards we are
proposing to remove. Since PM emissions are criteria pollutant
emissions, we are retaining and not reopening the PM emission standards
for APUs, and we propose to migrate 40 CFR 1037.106(g) to a new 40 CFR
1037.102(c). We note that the APUs under this specific proposed
revision are certified under the nonroad compression-ignition engine
regulations in 40 CFR part 1039, and existing 40 CFR 1039.699 includes
references to the APU standards in 40 CFR part 1037. We propose to
modify 40 CFR 1039.699(a) and (n) to refer to the proposed new 40 CFR
1037.102 instead of 40 CFR 1037.106, which we propose to remove.
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\137\ See 81 FR 73576-73580.
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In 40 CFR part 1037, subpart C, we propose to remove 40 CFR
1037.231, 1037.232, and 1037.241 that only apply for certifying heavy-
duty vehicles to the GHG emission standards. We are retaining 40 CFR
1037.235, which remains applicable for evaporative and refueling
testing that we are not reopening, with proposed revisions to remove
GHG-related testing requirements. Existing 40 CFR 1037.230 directs
manufacturers to divide their product lines into vehicle families based
on regulatory subcategories; however, with the proposed removal of GHG
standards, we also propose to remove the range of GHG-based vehicle
regulatory subcategories. Therefore, for the purpose of defining
vehicle families, we propose to amend 40 CFR 1037.230 to reflect the
vehicle types outlined in the proposed 40 CFR 1037.102. Specifically,
we propose that manufacturers would create a single vehicle family for
all vehicles with propulsion engines that are certified to the criteria
pollutant standards of 40 CFR 86.007-11 or 86.008-10, or 40 CFR part
1036, except that new tractors with auxiliary power units would be in a
separate family, and vehicles subject to evaporative or refueling
standards would be in families as described in existing 40 CFR 86.1812.
We propose all specialty vehicles would be a single vehicle family, and
all glider vehicles would be in a single vehicle family. Finally, we
propose that all vehicles with no propulsion engine, such as battery
electric vehicles and fuel cell electric vehicles, would be in a single
vehicle family.
With the updated vehicle families, we propose to revise 40 CFR
1037.205, which defines what manufacturers would include in their
application for certification. The proposed 40 CFR 1037.205 includes
existing information required for all applications for certification,
and more clearly defines what specific information would be required
for each of the vehicle families proposed in 40 CFR 1037.230.
We propose to remove 40 CFR part 1037, subpart D, in its entirety
because it describes the testing of production vehicles to be certified
to the heavy-duty CO2 emission standards. The provisions in
40 CFR 1037.301 through 1037.320 include audit procedures for inputs to
the Greenhouse gas Emissions Model (GEM), tractor aerodynamic testing,
powertrain testing, and axle and transmission testing.
We propose to remove 40 CFR part 1037, subpart E, in its entirety
because it includes the requirements for testing of in-use vehicles and
applies only to GHG emission standards.
We propose to remove 40 CFR part 1037, subpart F, in its entirety
because it includes the testing and modeling provisions necessary to
certify heavy-duty vehicles to the CO2 emission standards.
The provisions in 40 CFR 1037.501 through 1037.570 include procedures
for vehicle-based duty cycles for measuring GHG emissions, aerodynamic
testing, powertrain component testing, testing with hybrid power take-
off units, and the use of GEM.
We propose to remove several sections of 40 CFR part 1037, subpart
G, relating to special compliance provisions for the heavy-duty vehicle
GHG emission standards. Specifically, we propose to remove 40 CFR
1037.610 through 1037.615, 1037.630, 1037.631, and 1037.640 through
1037.670. These sections include provisions related to off-cycle
technologies, advanced technologies, special purpose tractors, variable
vehicle speed limiters, idle reduction technologies, in-use tractor
[[Page 36324]]
testing, and optional tractor CO2 emission standards.
We propose to remove 40 CFR part 1037, subpart H in its entirety.
The provisions of 40 CFR 1037.701 through 1037.750 describe the
averaging, banking, and trading of CO2 emission credits,
along with associated recordkeeping and reporting requirements.
We propose several revisions in 40 CFR part 1037, subpart I, to
remove GHG-specific definitions from 40 CFR 1037.801, and symbols,
abbreviations, and acronyms from 40 CFR 1037.805. We also propose to
remove 40 CFR 1037.810, which includes materials incorporated by
reference to support testing to demonstrate compliance with the heavy-
duty vehicle GHG standards. This includes, but is not limited to, the
GEM model and test procedures for measuring the rolling resistance of
tires, tire revolutions per mile, and aerodynamics using coastdown,
wind tunnel, and computational fluid dynamics.
Lastly, we propose to remove all appendices to 40 CFR part 1037.
Appendices A, B, and D include the test cycles related to heavy-duty
vehicle GHG standards. Appendix C includes the emission control
identifiers for GHG emission labels. Appendix E includes the power
take-off unit utility factors applied in GHG-specific test procedures.
c. Relationship Between the EPA's GHG and NHTSA's Fuel Efficiency
Medium- and Heavy-Duty Programs
The current certification and compliance process as relevant for
NHTSA is as follows, separately for heavy-duty engines and heavy-duty
vehicles:
1. Manufacturers submit fuel consumption data to the EPA using the
EPA's electronic certification system following EPA test procedures
included in 40 CFR parts 1036 and 1037;
2. The EPA issues certificates of conformity to the manufacturers;
3. Before and during the model year, the EPA sends the fuel
consumption data and associated information to NHTSA;
4. After the model year, the EPA analyzes end-of-year reports
submitted to the EPA by manufacturers for compliance and shares the
fuel consumption data with NHTSA; and
5. NHTSA manages its compliance process related to the fuel
consumption standards.
NHTSA's medium- and heavy-duty fuel efficiency regulations in 49
CFR part 535 refer to several sections in EPA's 40 CFR parts 1036 and
1037 that we are proposing to modify or remove. The provisions NHTSA's
regulations reference from EPA's heavy-duty engine regulations include
40 CFR 1036.1, 1036.108, 1036.150, 1036.205, 1036.225, 1036.230,
1036.235, 1036.250, 1036.255, 1036.301, 1036.501, 1036.505, 1036.510,
1036.512, 1036.525, 1036.535, 1036.540, 1036.545, 1036.620, 1036.725,
1036.730, 1036.740, 1036.745, and some definitions in 1036.801. The
provisions NHTSA's regulations reference from EPA's heavy-duty vehicle
regulations include 40 CFR 1037.105, 1037.106, 1037.140, 1037.150,
1037.205, 1037.210, 1037.225, 1037.230, 1037.232, 1037.250, 1037.255,
1037.301, 1037.305, 1037.320, 1037 subpart F broadly, 1037.510,
1037.520, 1037.525, 1037.527, 1037.528, 1037.530, 1037.532, 1037.534,
1037.540, 1037.560, 1037.565, 1037.570, 1037.601, 1037.605, 1037.610,
1037.615, 1037.620, 1037.621, 1037.622, 1037.631, 1037.660, 1037.725,
1037.730, 1037.740, 1037.745, 1037.755, and some definitions in
1037.801. We request comment on whether any of these provisions should
be retained with a CFR notation throughout 40 CFR parts 1036 and 1037
explaining that these sections only apply to NHTSA's heavy-duty fuel
efficiency program.
We propose to remove 40 CFR 1036.755 and 1037.755, which describe
the information the EPA would provide to the Department of
Transportation related to heavy-duty engine and vehicle fuel
consumption. We note that NHTSA's reporting and recordkeeping
regulation in 49 CFR 535.8(a)(6) directs manufacturers to submit
information to EPA. 49 CFR 535.8(a)(6) also provides direction to
manufacturers in instances where the EPA does not have an electronic
pathway to receive the information, to send it through an electronic
portal identified by NHTSA, through the NHTSA CAFE database, or to send
hardcopy documents to the address provided in the regulations.\138\ We
request comment on the time required to transition from manufacturers
supplying data to the EPA to supplying the data directly to NHTSA.
---------------------------------------------------------------------------
\138\ See 49 CFR 535.8(a)(6).
---------------------------------------------------------------------------
VII. Requests for Comment
The EPA is specifically soliciting comment on key aspects of the
proposed rule. To facilitate comment on those portions of the rule, the
EPA has indexed each comment solicitation with a unique identifier
below (e.g., ``C-1'', ``C-2'') to provide a consistent framework for
effective and efficient provision of comments. Accordingly, we ask that
commenters include the corresponding identifier when providing comments
relevant to that comment solicitation. We ask that commenters include
the identifier either in a heading or within the text of each comment,
to make clear which comment solicitation is being addressed. We note
that we are not limiting comment to these identified areas.
Specifically, we are soliciting comment on the following:
1. All aspects of this proposal, including legal and scientific
developments that are being subject to public comment for the first
time (C-1).
2. The scientific underpinnings of the Endangerment Finding are
weaker than previously believed and contradicted by empirical data,
peer-reviewed studies, and scientific developments since 2009 (C-2).
3. The EPA is not proposing to reopen or substantively modify at
this time any regulations necessary for criteria pollutant and air
toxic measurement and standards, CAFE testing, and associated fuel
economy labeling requirements. If there are any elements of our
regulations, test procedures, or GHG emission models proposed for
removal that should remain to support other programs outside of the
EPA's GHG standards, we are seeking comment on what those elements are
and why their preservation in the CFR is necessary (C-3).
4. We seek comment on the nature and extent of any reliance
interests that may have arisen from our assertion of regulatory
authority over GHG emissions from new motor vehicles and engines and
are committed to assessing any such interests, determining whether they
are significant, and weighing such interests against competing
rationales, as required by law (C-4).
5. We seek comment on whether regulated parties have any
significant reliance interests in our GHG emission standards for new
motor vehicles and new motor vehicle engines (C-5).
6. We seek comment on whether any reliance interests in national
uniformity and preemption would support adopting certain rationales and
not finalizing other rationales (C-6).
7. We seek comment on whether additional stakeholders have reliance
interests in GHG emission standards for new motor vehicles and engines
(C-7).
8. We seek comment on potential reliance interests in GHG emission
standards for global climate change concerns under CAA section 202(a),
including on whether such reliance justifies retaining such standards
and the extent to which potential dangers are addressed, or could be
addressed, under more specific authorities (C-8).
9. We seek comment on reliance interests in the Endangerment
Finding
[[Page 36325]]
and GHG emission standards issued under CAA section 202(a) and reserve
the right to direct out of scope comments to the appropriate rulemaking
docket for the applicable regulatory action (C-9).
10. We seek comment on the continued preemptive effect of the CAA
in the event that the EPA finalizes the proposed rescission or
otherwise concludes that it lacks authority to regulate GHG emissions
under CAA section 202(a) or any other specific regulatory provision of
the CAA (C-10).
11. We seek comment on the proposed interpretation of CAA 202(a) as
discussed in section III.A.1 of this preamble, including the rationales
presented in that section and any further rationales that commenters
believe support, or detract from, this interpretation (C-11).
12. We seek comment on the rationale presented in section V of this
preamble, including on the proper interpretation of ``requisite
technology,'' the appropriate standard for measuring pollution
prevention and control, and the scientific threshold for determining
measurable impacts on trends in climate change (C-12).
13. We seek comment on the proposed bases for repeal presented in
section V of this preamble, including on the economics of fleet
turnover, the relative efficiency and emission reductions achieved by
newer vehicles, and the potential costs to air quality of retaining
standards that may slow fleet turnover as compared to the potential
benefits of retaining GHG emission standards in response to global
climate change concerns (C-13).
14. We seek comment on the rationales presented in section V of
this preamble, including on whether such public welfare considerations
can and should be considered when prescribing and revising emission
standards under CAA section 202(a) (C-14).
15. We seek comment on how to give effect to the statutory language
discussed in section V of this preamble as incorporated into the
reference in CAA section 202(a) to effects on ``public health or
welfare'' (C-15).
16. We request comment on all proposed changes described in section
VI of this preamble, including on any additional regulatory provisions
for engines and vehicles that should be removed as part of repealing
the GHG standards or should be retained to effectuate unrelated
standards that we are not proposing to repeal or revise (C-16).
17. NHTSA's medium- and heavy-duty fuel efficiency regulations in
49 CFR part 535 refer to several sections in the EPA's 40 CFR parts
1036 and 1037 that we are proposing to modify or remove. We request
comment on whether any of these provisions should be retained for the
final rule with a CFR notation throughout 40 CFR parts 1036 and 1037
explaining that these sections only apply to NHTSA's heavy-duty fuel
efficiency program (C-17).
18. We request comment on the time required to transition from
requiring manufacturers to supply relevant data to the EPA to requiring
that they supply the data directly to NHTSA (C-18).
19. We request comment on all proposed changes described in
preamble section VI, including suggestions to remove additional
regulatory provisions for such engines and vehicles for purposes of GHG
regulation or to retain provisions we propose to remove. Specifically,
we request comment on the proposed regulatory changes for the light-
and medium-duty vehicle programs under 40 CFR parts 85, 86, and 600,
and whether additional changes should be considered for purposes of GHG
regulation (C-19).
20. We request comment on all proposed changes described in
preamble section VI, including suggestions to remove additional
regulatory provisions for such engines and vehicles for purposes of GHG
regulation or to retain provisions we propose to remove. Specifically,
we request comment on the proposed regulatory changes for the heavy-
duty engine and vehicle programs under 40 CFR parts 1036 and 1037 and
whether we should consider additional changes for purposes of GHG
regulation (C-20).
21. We request comment on the analysis provided within section VIII
related to the benefits and costs of the proposed action and whether
benefit cost analysis is an appropriate and lawful basis for repealing
the Endangerment Finding and/or resulting vehicle standards (C-21).
22. The information collection activities in this proposed rule
have been submitted for approval to OMB under the Paperwork Reduction
Act (PRA), as described in section VIII.C of this preamble. Submit your
comments on the Agency's description of the information that would no
longer be required to be provided, the accuracy of the provided burden
savings estimates, and any suggested methods for minimizing respondent
burden to the EPA using the docket identified at the beginning of this
rule (C-22).
23. Stakeholders state that NCA5 does not meet the requirements
under Executive Order 14303 and deviated from OMB guidelines on
quality, objectivity, utility, and integrity of information
disseminated by Federal agencies. The Administrator takes these
concerns seriously and seeks public comment on the validity of these
concerns and how they should be taken into account when determining
whether to finalize any of the alternatives proposed in this action (C-
23).
24. We further propose that Massachusetts must be read together
with the Supreme Court's decisions in West Virginia and UARG, which
applied the major questions doctrine to statutory provisions similar to
CAA section 202(a). To that end, we seek comment on whether
Massachusetts applied the major questions doctrine in the first
instance, and, if it did, whether that analysis informs the meaning of
CAA section 202(a) on its own terms and in light of UARG and West
Virginia (C-24).
25. We propose that the EPA's course of rulemaking has not been
limited to emission standards as anticipated in Massachusetts. To that
end, we seek comment on whether a new analysis is required because the
EPA's rulemakings in response to the Endangerment Finding have included
electric vehicle mandates that require shifting the national vehicle
fleet from one type of vehicle and vehicle fuel to another (C-25).
26. We propose that even if intervening legal developments have not
foreclosed the regulation of GHG emissions from new motor vehicles and
engines under CAA section 202(a), they provide a reasonable basis for
the Administrator to approach the inquiry with greater caution today
than was applied in the Endangerment Finding. We propose that the
Administrator's new approach requires rescinding the Endangerment
Finding as fundamentally inconsistent with the framework set out in
this proposed alternative. We seek comment on this alternative
proposal, including on the breadth of the Administrator's discretion to
exercise judgment by rejecting the approach taken in the Endangerment
Finding and the results of adopting a different approach (C-26).
27. We seek comment on any additional aspects of the Endangerment
Finding that may have fallen short of the administrative law
requirement that agency action be reasonable and reasonably explained.
Conversely, we seek comment on why the approach taken in the
Endangerment Finding remains reasonable given the legal and scientific
developments discussed in this proposal, and the impact, if any, of the
EPA's denial of rulemaking petitions in 2022 and 2010 on this
alternative proposal (C-27).
[[Page 36326]]
VIII. Statutory and Executive Order Reviews
Additional information about these statutes and Executive Orders
can be found at http://www.epa.gov/laws-regulations/laws-and-executive-orders.
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 14094: Modernizing Regulatory Review
This proposed action is an economically significant regulatory
action that was submitted to the Office of Management and Budget (OMB)
for review. Any changes made have been documented in the docket. The
EPA has prepared a draft Regulatory Impact Analysis (RIA) for this
proposed action to project impacts as required by E.O. 12866, and it
can be found in the docket.\139\ The EPA has not relied upon any aspect
of the draft RIA as justification for this proposed rulemaking.
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\139\ ``Reconsideration of 2009 Endangerment Finding and
Greenhouse Gas vehicle Standards: Draft Regulatory Impact
Analysis.'' EPA-420-D-25-002. July 2025.
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The EPA considered relying on our most recent RIAs from 2024
relating to GHG standards for motor vehicles \140\ (2024 GHG Vehicle
RIAs) for projecting impacts of this action. However, the 2024 GHG
Vehicle RIAs significantly relied upon assumptions that we no longer
believe are appropriate and that would significantly impact the costs
and benefits of this proposed rule. Those assumptions include, but are
not limited to:
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\140\ See ``Multi-Pollutant Emissions Standards for Model Years
2027 and Later Light-Duty and Medium-Duty Vehicles. Regulatory
Impact Analysis.'' EPA-420-R-24-004. March 2024; ``Greenhouse Gas
Emissions Standards for Heavy-Duty Vehicles: Phase 3. Regulatory
Impact Analysis''. EPA-420-R-24-006. March 2024.
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1. The impact and existence of EV-related tax credits and other
subsidies from the 2022 IRA, which have been repealed in part by the
2025 OBBB and were incorporated into the RIA baseline;
2. The impact of Congress' disapproval under the CRA of the EPA's
waiver rule for California's Advanced Clean Truck regulation, which was
incorporated into the RIA baseline but is no longer in force in
California or any other State;
3. Changes in consumers' interest in purchasing EVs;
4. Future gasoline and diesel prices due to changes in
Administration policy since 2024;
5. Changes in the power generation sector as a result of recent
projections for data center demands and legislative amendments in the
2025 OBBB that impact the economics of EV penetration and use; and
6. Access to capital for all consumers due to differences in prices
and the respective cost impacts on vehicles, given that the RIAs from
2024 assumed unlimited access to capital.
Changes in these assumptions impact all aspects of the 2024 RIAs
and, thus, the EPA cannot rely upon those assessments to confidently
and appropriately quantify or monetize many of the impacts from this
proposed action. In the draft RIA for this proposal, the EPA presents
estimated results from two analytical methods for projecting impacts on
costs and benefits from removing the GHG standards for LD, MD and HD
vehicles and HD engines.
The EPA presents five different modeled scenarios using one of the
analytical methods in the draft RIA, which are summarized here in
Tables 6 and 7. The first scenario contains all the same assumptions
and inputs as presented in the 2024 RIAs. The second scenario estimates
the impacts of removing the IRA and the California Advanced Clean Truck
(ACT) rule, which the EPA included in the baseline for the 2024 RIAs
assessments. Recognizing the significant uncertainties related to
future gasoline and diesel prices, the third scenario considers lower
fuel prices, in addition to the removal of IRA and the ACT rule. All
other assumptions and inputs are the same as those used in the 2024
RIAs. The fourth and fifth scenarios build on the second and third
scenarios respectively, accounting for only the first two and half
years of fuel savings in estimating the net monetized impact of this
proposed rule.
Table 6 and Table 7 show the net present value of the monetized
savings, costs, and net savings of the five scenarios presented at 7
and 3 percent discount rates, respectively.
Table 6--Monetized Savings, Costs, and Net Savings at 7 Percent Net Present Value
[Billions of 2022 dollars] *
--------------------------------------------------------------------------------------------------------------------------------------------------------
2024 Light- & medium-
duty vehicle
multipollutant final 2024 LMDV and HDP3 2024 LMDV and HDP3
rule (LMDV) and 2024 LMDV and HDP3 2024 LMDV and HDP3 rule analysis, no rule; no IRA and
greenhouse gas rule analysis, no rule, no IRA and IRA and ACT, 2.5 ACT, low liquid fuel
emissions standards IRA and ACT ACT; low liquid fuel years of fuel prices, 2.5 years of
for heavy-duty prices savings fuel savings
vehicles-phase 3
(HDP3) rule analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
Savings................................... $570 $640 $640 $640 $640
Costs..................................... 590 690 420 320 260
-------------------------------------------------------------------------------------------------------------
Net Savings........................... (30) (50) 220 320 380
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Results may not sum due to rounding.
Table 7--Monetized Savings, Costs and Net Savings at 3 Percent Net Present Value
[Billions of 2022 dollars] *
--------------------------------------------------------------------------------------------------------------------------------------------------------
2024 LMDV and HDP3 2024 LMDV and HDP3
2024 LMDV and HDP3 2024 LMDV and HDP3 rule analysis; no rule; no IRA and
2024 LMDV and HDP3 rule analysis, no rule, no IRA and IRA and ACT, 2.5 ACT, low liquid fuel
rule analysis IRA and ACT ACT; low liquid fuel years of fuel prices, 2.5 years of
prices savings fuel savings
--------------------------------------------------------------------------------------------------------------------------------------------------------
Savings................................... $950 $1,030 $1,030 $1,030 $1,030
[[Page 36327]]
Costs..................................... 1,210 1,390 870 660 550
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Net Savings........................... (260) (350) 160 380 490
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Results may not sum due to rounding.
The other analytical method which utilizes a revealed preference
approach) can be found in the draft RIA.
The EPA requests comment on all aspects of the draft RIA, and on
whether there are other approaches the EPA should consider for
projecting the impacts of this proposed rule (C-20). We are requesting
comment from stakeholders about what expected and modeled impacts would
be from this proposal.
B. Executive Order 14192: Unleashing Prosperity Through Deregulation
This action is expected to be an Executive Order 14192 deregulatory
action. A summary of the projected costs savings can be found in the
draft RIA.
C. Paperwork Reduction Act (PRA)
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in Title 40 of the CFR are listed in 40 CFR part 9.
Submit your comments on the Agency's description of the information
that would no longer be required to be provided, the accuracy of the
provided burden savings estimates and any suggested methods for
minimizing respondent burden to the EPA using the docket identified at
the beginning of this rule. The EPA will respond to any ICR-related
comments in the final rule. You may also send your ICR-related comments
to OMB's Office of Information and Regulatory Affairs using the
interface at www.reginfo.gov/public/do/PRAMain. Find the particular
information collection by selecting ``Currently under Review--Open for
Public Comments'' or by using the search function. OMB must receive
comments no later than September 2, 2025.
The information collection activities in this proposed rule have
been submitted for approval to the OMB under the PRA.
1. Light- and Medium-Duty Vehicle--2024 Final Rule
The ICR document prepared by the EPA for removal of the light- and
medium-duty vehicle GHG requirements has been assigned EPA ICR 2750.03,
revising EPA ICR 2750.02 (OMB 2060-0764). You can find a copy of the
ICR in the docket for this rule and it is briefly summarized here.
The EPA is proposing to remove all regulations that require light-
and medium-duty vehicle manufacturers to measure, report, or comply
with standards for GHG emissions. Information collected to assure
compliance with those requirements is no longer needed under this
proposal. All other requirements covered by 2750.02 remain in effect.
Respondents/affected entities: Light- and medium-duty vehicle
manufacturers, alternative fuel converters, and independent commercial
importers.
Respondent's obligation to respond: This proposal relieves
manufacturers of the burden to provide certain information to the EPA
as part of their annual model year vehicle certification under section
208(a) of the CAA, which is required prior to entering vehicles into
commerce. Participation in some programs is voluntary; but once a
manufacturer has elected to participate, it must submit the required
information.
Estimated number of respondents: 35 affected entities.
Frequency of response: Annually or on occasion, depending on the
type of response.
Revised total estimated burden: 138,443 hours (per year) for
remaining regulatory requirements covered by this ICR. Burden is
defined at 5 CFR 1320.3(b).
Revised total estimated cost: $26.3 million per year for remaining
regulatory requirements covered by this ICR, which includes an
estimated $14.2 million annualized capital or operation and maintenance
costs.
2. Heavy-Duty Vehicle GHG Phase 3--2024 Final Rule
The ICR document prepared by the EPA for removal of the heavy-duty
GHG Phase 3 requirements has been assigned EPA ICR 2734.03, revising
EPA ICR 2734.02 (OMB 2060-0753). You can find a copy of the ICR in the
docket for this rule and it is briefly summarized here.
The EPA is proposing to remove all regulations that require heavy-
duty motor vehicle and heavy-duty motor vehicle engine manufacturers to
measure, report, or comply with the heavy-duty GHG Phase 3 standards.
Information collected to assure compliance with those requirements is
no longer needed under this proposal.
Respondents/affected entities: Manufacturers of heavy-duty onroad
vehicles.
Respondent's obligation to respond: This proposal relieves
manufacturers of the burden to provide certain information to the EPA
as part of their annual model year engine and vehicle certification
under section 203(a) of the CAA, which is required prior to entering
vehicles into commerce.
Estimated number of respondents: 77 affected entities.
Frequency of response: Originally expected to be one-time burden;
now, no requirement to report.
Revised total estimated burden: 0 hours. Burden is defined at 5 CFR
1320.03(b).
Revised total estimated cost: $0.
3. Nonroad Compression-Ignition Engines and On-Highway Heavy Duty
Engines, Supporting Statement for Information Collection Request (March
2023 Revision)
The ICR document prepared by the EPA for removal of the existing
Phase 2 and earlier GHG requirements for heavy-duty engines and
vehicles has been assigned EPA ICR 1684.22, revising EPA ICR 1684.21
(OMB 2060-0287). You can find a copy of the ICR in the docket for this
rule and it is briefly summarized here.
[[Page 36328]]
The EPA is proposing to remove all regulations that require heavy-
duty motor vehicle and heavy-duty motor vehicle engine manufacturers to
measure, report, or comply with standards for GHG emissions.
Information collected to assure compliance with those requirements is
no longer needed under this proposal. All other requirements covered by
EPA ICR 1684.21 remain in effect.
Respondents/affected entities: Manufacturers of heavy-duty onroad
vehicles and engines.
Respondent's obligation to respond: This proposal relieves
manufacturers of the burden to provide certain information to the EPA
as part of their annual model year engine and vehicle certification
under CAA section 203(a), which is required prior to entering vehicles
into commerce. Participation in some programs is voluntary; but once a
manufacturer has elected to participate, it must submit the required
information.
Estimated number of respondents: 568 affected entities.
Frequency of response: Annually or on occasion, depending on the
type of response.
Revised total estimated burden: 137,824 hours for remaining
regulatory requirements covered by this ICR. Burden is defined at 5 CFR
1320.03(b).
Revised total estimated cost: $30.3 million for remaining
regulatory requirements covered by this ICR, which includes an
estimated $17.9 million annualized capital or operation and maintenance
costs.
D. Regulatory Flexibility Act (RFA)
I certify that this proposed action would not have a significant
economic impact on a substantial number of small entities under the
Regulatory Flexibility Act (RFA). In making this determination, the EPA
concludes that the impact of concern for this rule is any significant
adverse economic impact on small entities, and that the agency is
certifying that this rule will not have a significant economic impact
on a substantial number of small entities because the rule relieves
regulatory burden on the small entities subject to the rule.
The regulated entities that are subject to the regulations we are
proposing to remove in this proposed rule are engine and vehicle
manufacturers, alternative fuel converters, and independent commercial
importers subject to GHG emissions standards for vehicles. The Agency
is certifying that this proposed action would not have a significant
economic impact on a substantial number of small entities because the
proposed action would relieve regulatory burden on all entities,
including all small entities, subject to the current rules. This action
proposes to remove portions of the regulations of the standard-setting
parts directly related to GHG emission standards and compliance
provisions for implementing the EPA's GHG engine and vehicle programs.
We do not anticipate that there would be any significant adverse
economic impact on directly regulated small entities as a result of
these revisions. We have therefore concluded that this proposed action
would, if finalized, relieve regulatory burden for all directly
regulated small entities. The EPA provides additional information on
the RFA in Section 7 of the Draft Regulatory Impact Analysis document
for this proposal.
E. Unfunded Mandates Reform Act (UMRA)
This proposed action does not contain an unfunded mandate of $100
million (adjusted annually for inflation) or more (in 1995 dollars) as
described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or
uniquely affect small governments. The proposed action would, if
finalized, impose no enforceable duty on any state, local, or tribal
governments, and would relieve duties with respect to the private
sector.
F. Executive Order 13132: Federalism
This proposed action would not have federalism implications as
specified in Executive Order 13132. If finalized, it would not have
substantial direct effects on the states, on the relationship between
the national government and the states, or on the distribution of power
and responsibilities among the various levels of government.
G. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This proposed action would not have tribal implications as
specified in Executive Order 13175. If finalized, it would not have
substantial direct effects on tribal governments, on the relationship
between the federal government and Indian tribes, or on the
distribution of power and responsibilities between the federal
government and Indian tribes, as specified in Executive Order 13175.
Thus, Executive Order 13175 does not apply to this proposed action.
H. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
Executive Order 13045 directs federal agencies to include an
evaluation of the health and safety effects of the planned regulation
on children in federal health and safety standards and explain why the
regulation is preferable to potentially effective and reasonably
feasible alternatives. This action is subject to Executive Order 13045
because it is a significant regulatory action under section 3(f)(1) of
Executive Order 12866, and the EPA believes the environmental health or
safety risks of the pollutants impacted by this action may have a
disproportionate effect on children. The 2021 Policy on Children's
Health also applies to this action.\141\
---------------------------------------------------------------------------
\141\ U.S. Environmental Protection Agency. (2021). 2021 Policy
on Children's Health: https://www.epa.gov/system/files/documents/2021-10/2021-policy-on-childrens-health.pdf.
---------------------------------------------------------------------------
Although the GHG emissions at issue in this rulemaking do not have
direct impacts on human health, we acknowledge the possibility that
this proposal could marginally impact emissions of criteria pollutants
and air toxics. Children are not expected to experience greater ambient
concentrations of air pollutants than the general population. However,
children are more susceptible than adults to air pollution, and
children tend to spend increased time outdoors. Children make up a
substantial fraction of the U.S. population, and often have unique
factors that contribute to their increased risk of experiencing a
health effect from exposures to ambient air pollutants because of their
continuous growth and development. Children are more susceptible than
adults to many air pollutants because they have (1) a developing
respiratory system, (2) increased ventilation rates relative to body
mass compared with adults, (3) an increased proportion of oral
breathing, particularly in boys, relative to adults, and (4) behaviors
that increase chances for exposure. Even before birth, the developing
fetus may be exposed to air pollutants through the mother that affect
development when the mother is exposed. We note that, as explained
above, this proposed action would not impact separate regulatory
controls for criteria pollutants or separate standards set by NHTSA. At
this time, the EPA does not believe that the proposed action would have
a material adverse impact on the health of individuals with respect to
non-GHG air pollutants, including on children, because the EPA
anticipates that the impacts of repealing GHG emission regulations
would have only marginal and incidental impacts on the emission of non-
GHG air pollutants. Potential health impacts of such air pollutants
will continue to be controlled through direct emissions limits and a
[[Page 36329]]
number of other programs that target regional and national air quality,
including the NAAQS program.
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This proposed action, which is a significant regulatory action
under Executive Order 12866, would have a significant effect on the
supply, distribution or use of energy. The EPA has prepared a Statement
of Energy Effects for this proposed action as follows.
This action proposes to remove the GHG emission standards and
related compliance provisions for light-, medium-, and heavy-duty
engines and vehicles. This action would, if finalized, result in an
estimated increase in the consumption of petroleum and an estimated
reduction in the consumption of electricity.
J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR
Part 51
This proposed action involves technical standards. However, the
proposed changes to the regulation include removing GHG emission
standards and the corresponding measurement and compliance procedures,
some of which also involve removing existing references to voluntary
consensus standards and other technical standards. This proposed action
does not include any new requirements or new references to technical
standards.
List of Subjects
40 CFR Part 85
Confidential business information, Greenhouse gases, Imports,
Labeling, Motor vehicle pollution, Reporting and recordkeeping
requirements, Research Warranties.
40 CFR Part 86
Environmental protection, Administrative practice and procedure,
Confidential business information, Incorporation by reference,
Labeling, Motor vehicle pollution, Reporting and recordkeeping
requirements.
40 CFR Part 600
Environmental protection, Administrative practice and procedure,
Electric power, Fuel economy, Greenhouse gases, Labeling, Reporting and
recordkeeping requirements.
40 CFR Part 1036
Environmental protection, Administrative practice and procedure,
Air pollution control, Confidential business information, Greenhouse
gases, Incorporation by reference, Labeling, Motor vehicle pollution,
Reporting and recordkeeping requirements, Warranties.
40 CFR Part 1037
Environmental protection, Administrative practice and procedure,
Air pollution control, Confidential business information, Incorporation
by reference, Labeling, Motor vehicle pollution, Reporting and
recordkeeping requirements, Warranties.
40 CFR Part 1039
Administrative practice and procedure, Air pollution control,
Confidential business information, Imports, Labeling, Penalties,
Reporting and recordkeeping requirements, Warranties.
Lee Zeldin,
Administrator.
For the reasons set out in the preamble, we propose to amend title
40, Chapter I of the Code of Federal Regulations as set forth below.
PART 85--CONTROL OF AIR POLLUTION FROM MOBILE SOURCES
0
1. The authority citation for part 85 continues to read as follows:
Authority: 42 U.S.C. 7401-7671q.
Sec. 85.525 [Amended]
0
2. Amend Sec. 85.525 by removing and reserving paragraph (b).
0
3. Amend Sec. 85.1515 by revising paragraph (d) to read as follows:
Sec. 85.1515 Emission standards and test procedures applicable to
imported nonconforming motor vehicles and motor vehicle engines.
* * * * *
(d) An ICI may not certify using nonconformance penalties.
Sec. 85.1803 [Amended]
0
4. Amend Sec. 85.1803 by removing paragraph (e).
Sec. 85.1805 [Amended]
0
5. Amend Sec. 85.1805 by removing and reserving paragraph (b).
0
6. Amend Sec. 86.1902 by removing and reserving paragraph (b)(2) and
revising paragraph (d). The revision reads as follows:
Sec. 85.1902 Definitions.
* * * * *
(d) Voluntary emissions recall means a repair, adjustment, or
modification program voluntarily initiated and conducted by a
manufacturer to remedy any emission-related defect for which direct
notification of vehicle or engine owners has been provided.
* * * * *
Sec. 85.2103 [Amended]
0
7. Amend Sec. 85.2103 by removing paragraphs (d)(1)(v) and (d)(3).
PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES
AND ENGINES
0
8. The authority citation for part 86 continues to read as follows:
Authority: 42 U.S.C. 7401-7671q.
Sec. 86.1 [Amended]
0
9. Amend Sec. 86.1 by removing and reserving paragraphs (c)(2) and (3)
and (f)(3), (17), (21), and (22) and removing paragraph (h).
0
10. Amend Sec. 86.007-11 by revising paragraphs (g)(1) and (6) to read
as follows:
Sec. 86.007-11 Emission standards and supplemental requirements for
2007 and later model year diesel heavy-duty engines and vehicles.
* * * * *
(g) * * *
(1) The engines must be of a configuration that is identical to one
that is certified under 40 CFR part 1039, and must be certified with a
Family Emission Limit for PM of 0.020 g/kW-hr using the same duty
cycles that apply under 40 CFR part 1039.
* * * * *
(6) Engines certified under this paragraph (g) may not generate or
use emission credits under this part or under 40 CFR part 1039.
* * * * *
0
11. Amend Sec. 86.008-10 by revising paragraph (g)(6) to read as
follows:
Sec. 86.008-10 Emission standards for 2008 and later model year Otto-
cycle heavy-duty engines and vehicles.
* * * * *
(g) * * *
(6) Engines certified under this paragraph (g) may not generate or
use emission credits under this part.
* * * * *
0
12. Amend Sec. 86.1801-12 by:
0
a. Removing and reserving paragraph (a)(2)(ii)(B);
0
b. Revising paragraphs (a)(3), (b), and (i); and
0
c. Removing paragraphs (j) and (k).
The revisions read as follows:
Sec. 86.1801-12 Applicability.
(a) * * *
(3) The provisions of this subpart do not apply to heavy-duty
vehicles above 14,000 pounds GVWR (see Sec. 86.016-1
[[Page 36330]]
and 40 CFR parts 1036 and 1037), except as follows:
(i) Heavy-duty vehicles above 14,000 pounds GVWR and at or below
19,500 pounds GVWR may be optionally certified to the exhaust emission
standards in this subpart if they are properly included in a test group
with similar vehicles at or below 14,000 pounds GVWR. Emission
standards apply to these vehicles as if they were Class 3 medium-duty
vehicles.
(ii) [Reserved]
(iii) Evaporative and refueling emission standards apply for heavy-
duty vehicles above 14,000 pounds GVWR as specified in 40 CFR 1037.103.
* * * * *
(b) Relationship to 40 CFR parts 1036 and 1037. If any heavy-duty
vehicle is not subject to standards and certification requirements
under this subpart, the vehicle and its installed engine are instead
subject to standards and certification requirements under 40 CFR parts
1036 and 1037, as applicable. If you optionally certify engines or
vehicles to standards under 40 CFR part 1036 or 40 CFR part 1037,
respectively, those engines or vehicles are subject to all the
regulatory requirements in 40 CFR parts 1036 and 1037 as if they were
mandatory.
* * * * *
(i) Types of pollutants. Criteria pollutant standards apply for
NOX, NMOG, HC, formaldehyde, PM, and CO, including exhaust,
evaporative, and refueling emission standards. These pollutants are
sometimes described collectively as ``criteria pollutants'' because
they are either criteria pollutants under the Clean Air Act or
precursors to the criteria pollutants ozone and PM.
0
13. Amend Sec. 86.1803-01 by:
0
a. Removing the definitions of ``AC1'', ``AC2'', ``Air Conditioning
Idle Test'', ``Base level'', ``Base tire'', ``Base vehicle'',
``Combined CO2'', ``Combined CREE'', and ``Configuration'';
0
b. Revising the definition of ``Defeat device'';
0
c. Removing and reserving paragraph (1) of the definition of
``Emergency vehicle'';
0
d. Revising the definition of ``Engine code'';
0
e. Removing the definition of ``Footprint'', ``Full size pickup
truck'', ``Mild hybrid electric vehicle'', ``Strong hybrid electric
vehicle'', ``Subconfiguration'', ``Track width'', and ``Transmission
class''; and
0
f. Adding a definition of ``Work factor'' in alphabetical order.
The revisions and addition read as follows:
Sec. 86.1803-01 Definitions.
* * * * *
Defeat device means an auxiliary emission control device (AECD)
that reduces the effectiveness of the emission control system under
conditions which may reasonably be expected to be encountered in normal
vehicle operation and use, unless:
(1) Such conditions are substantially included in driving cycles
specified in this subpart or the fuel economy test procedures in 40 CFR
part 600;
(2) The need for the AECD is justified in terms of protecting the
vehicle against damage or accident;
(3) The AECD does not go beyond the requirements of engine
starting; or
(4) The AECD applies only for emergency vehicles and the need is
justified in terms of preventing the vehicle from losing speed, torque,
or power due to abnormal conditions of the emission control system, or
in terms of preventing such abnormal conditions from occurring, during
operation related to emergency response. Examples of such abnormal
conditions may include excessive exhaust backpressure from an
overloaded particulate trap, and running out of diesel exhaust fluid
for engines that rely on urea-based selective catalytic reduction.
* * * * *
Engine code means a unique combination within a test group of
displacement, fuel injection (or carburetor) calibration, choke
calibration, distributor calibration, auxiliary emission control
devices, and other engine and emission control system components
specified by the Administrator. For electric vehicles, engine code
means a unique combination of manufacturer, electric traction motor,
motor configuration, motor controller, and energy storage device.*
* * * * *
Work factor, WF, means the characteristic value representing a
vehicle's work potential, calculated to the nearest pound using the
following equation:
WF = 0.75 x (GVWR - Curb Weight + xwd) + 0.25 x (GCWR - GVWR)
Where:
xwd = 500 pounds if the vehicle has four-wheel drive or all-wheel
drive; xwd = 0 pounds for all other vehicles.
* * * * *
0
14. Amend Sec. 86.1805-12 by revising paragraph (a) to read as
follows:
Sec. 86.1805-12 Useful life.
(a) Except as permitted under paragraph (b) of this section or
required under paragraphs (c) and (d) of this section, the full useful
life for all LDVs and LLDTs is a period of use of 10 years or 120,000
miles, whichever occurs first. The full useful life for all HLDTs,
MDPVs, and complete heavy-duty vehicles is a period of 11 years or
120,000 miles, whichever occurs first. These full useful life values
apply to all exhaust, evaporative and refueling emission requirements
except for standards which are specified to only be applicable at the
time of certification.
* * * * *
0
15. Revise Sec. 86.1805-17 to read as follows:
Sec. 86.1805-17 Useful life.
(a) General provisions. The useful life values specified in this
section apply for all exhaust, evaporative, refueling, and OBD emission
requirements described in this subpart, except for standards that are
specified to apply only at certification. Useful life values are
specified as a given number of calendar years or miles of driving,
whichever comes first.
(b) [Reserved]
(c) Cold temperature emission standards. The cold temperature NMHC
emission standards in Sec. 86.1811-17 apply for a useful life of 10
years or 120,000 miles for LDV and LLDT, and 11 years or 120,000 miles
for HLDT and HDV. The cold temperature CO emission standards in Sec.
86.1811-17 apply for a useful life of 5 years or 50,000 miles.
(d) Criteria pollutants. The useful life provisions of this
paragraph (d) apply for all emission standards not covered by paragraph
(c) of this section. This paragraph (d) applies for the cold
temperature emission standards in Sec. 86.1811-27(c). Except as
specified in paragraph (f) of this section and in Sec. Sec. 86.1811,
86.1813, and 86.1816, the useful life for LDT2, HLDT, MDPV, and HDV is
15 years or 150,000 miles. The useful life for LDV and LDT1 is 10 years
or 120,000 miles. Manufacturers may optionally certify LDV and LDT1 to
a useful life of 15 years or 150,000 miles, in which case the longer
useful life would apply for all the standards and requirements covered
by this paragraph (d).
(e) Intermediate useful life. Where exhaust emission standards are
specified for an intermediate useful life, these standards apply for
five years or 50,000 miles.
Sec. 86.1807-01 [Amended]
0
16. Amend Sec. 86.1807-01 by removing and reserving paragraph
(a)(3)(iv).
0
17. Amend Sec. 86.1809-12 by revising paragraph (d)(1) to read as
follows:
[[Page 36331]]
Sec. 86.1809-12 Prohibition of defeat devices.
* * * * *
(d) * * *
(1) The manufacturer must show to EPA's satisfaction that the
vehicle design does not incorporate strategies that unnecessarily
reduce emission control effectiveness exhibited over the driving cycles
specified in this subpart or the fuel economy test procedures in 40 CFR
part 600 when the vehicle is operated under conditions that may
reasonably be expected to be encountered in normal operation and use.
* * * * *
0
18. Amend Sec. 86.1810-09 by revising paragraph (f)(2) to read as
follows:
Sec. 86.1810-09 General standards; increase in emissions; unsafe
condition; waivers.
* * * * *
(f) * * *
(2) For vehicles that comply with the cold temperature NMHC
standards described in Sec. 86.1811-10(g), manufacturers must submit
an engineering evaluation indicating that common calibration approaches
are utilized at high altitudes (except when there are specific high
altitude calibration needs to deviate from low altitude emission
control practices). Any deviation from low altitude emission control
practices must be included in the auxiliary emission control device
(AECD) descriptions submitted at certification. Any AECD specific to
high altitude must require engineering emission data for EPA evaluation
to quantify any emission impact and validity of the AECD.
* * * * *
0
19. Amend Sec. 86.1810-17 by revising paragraph (j) to read as
follows:
Sec. 86.1810-17 General requirements.
* * * * *
(j) Small-volume manufacturers that modify a vehicle already
certified by a different company may recertify that vehicle under this
subpart S based on the vehicle supplier's compliance with fleet average
standards for criteria exhaust emissions and evaporative emissions as
follows:
(1) The recertifying manufacturer must certify the vehicle at bin
levels and family emission limits that are the same as or more
stringent than the corresponding bin levels and family emission limits
for the vehicle supplier.
(2) The recertifying manufacturer must meet all the standards and
requirements described in this subpart S, except for the fleet average
standards for criteria exhaust emissions and evaporative emissions.
(3) The vehicle supplier must send the small-volume manufacturer a
written statement accepting responsibility to include the subject
vehicles in the vehicle supplier's exhaust and evaporative fleet
average calculations in Sec. Sec. 86.1860-17 and 86.1864-10.
(4) The small-volume manufacturer must describe in the application
for certification how the two companies are working together to
demonstrate compliance for the subject vehicles. The application must
include the statement from the vehicle supplier described in paragraph
(j)(3) of this section.
(5) The vehicle supplier must include a statement that the vehicle
supplier is including the small volume manufacturer's sales volume and
emissions levels in the vehicle supplier's fleet average reports under
Sec. Sec. 86.1860-17 and 86.1864-10.
* * * * *
0
20. Amend Sec. 86.1805-12 by revising paragraph (a) to read as
follows:
Sec. 86.1811-17 Exhaust emission standards for light-duty vehicles,
light-duty trucks and medium-duty passenger vehicles.
(a) Applicability and general provisions. This section describes
exhaust emission standards that apply for model year 2017 and later
light-duty vehicles, light-duty trucks, and medium-duty passenger
vehicles. MDPVs are subject to all the same emission standards and
certification provisions that apply to LDT4. Some of the provisions of
this section also apply to heavy-duty vehicles as specified in Sec.
86.1816. See Sec. 86.1813 for evaporative and refueling emission
standards. This section may apply to vehicles from model years earlier
than 2017 as specified in paragraph (b)(11) of this section.
* * * * *
Sec. 86.1811-27 [Amended]
0
21. Amend Sec. 86.1811-27 by removing paragraph (a)(4).
Sec. 86.1815-27 [Removed]
0
22. Remove Sec. 86.1815-27.
0
23. Amend Sec. 86.1816-18 by revising paragraph (a) to read as
follows:
Sec. 86.1816-18 Emission standards for heavy-duty vehicles.
(a) Applicability and general provisions. This section describes
Tier 3 exhaust emission standards for complete heavy-duty vehicles.
These standards are optional for incomplete heavy-duty vehicles and for
heavy-duty vehicles above 14,000 pounds GVWR as described in Sec.
86.1801. See Sec. 86.1813 for evaporative and refueling emission
standards. This section starts to apply in model year 2018, except that
the provisions may apply to vehicles before model year 2018 as
specified in paragraph (b)(11) of this section. This section applies
for model year 2027 and later vehicles only as specified in Sec.
86.1811-27. Separate requirements apply for MDPV as specified in Sec.
86.1811. See subpart A of this part for requirements that apply for
incomplete heavy-duty vehicles and for heavy-duty engines certified
independent of the chassis. The following general provisions apply:
(1) Test all vehicles as described in this section using a chassis
dynamometer; establish appropriate load settings based on adjusted
loaded vehicle weight (see Sec. 86.1803).
(2) Some provisions apply differently depending on the vehicle's
power-to-weight ratio. Determine a vehicle's power-to-weight ratio by
dividing the engine's rated power by the vehicle's GVWR (in hp/pound).
For purposes of this section, if a test group includes multiple vehicle
configurations, use the vehicle with the highest power-to-weight ratio
to characterize the test group.
(3) Use E10 test fuel as required in Sec. 86.113, except as
specified in this section.
(4) Measure emissions from hybrid electric vehicles (including
plug-in hybrid electric vehicles) as described in 40 CFR part 1066,
subpart F, except that these procedures do not apply for plug-in hybrid
electric vehicles during charge-depleting operation.
* * * * *
Sec. Sec. 86.1818-12 and 86.1819-14 [Removed]
0
24. Remove Sec. Sec. 86.1818-12 and 86.1819-14.
0
25. Amend Sec. 86.1822-01 by revising paragraph (b) to read as
follows:
Sec. 86.1822-01 Durability data vehicle selection.
* * * * *
(b) The manufacturer may select, using good engineering judgment,
an equivalent or worst-case vehicle configuration in lieu of testing
the vehicle selected in paragraph (a) of this section. Carryover data
satisfying the provisions of Sec. 86.1839-01 may also be used in lieu
of testing the vehicle configuration selected in paragraph (a) of this
section.
Sec. 86.1823-08 [Amended]
0
26. Amend Sec. 86.1823-08 by removing and reserving paragraph (m).
0
27. Amend Sec. 86.1827-01 by revising paragraph (a)(5) to read as
follows:
[[Page 36332]]
Sec. 86.1827-01 Test group determination.
* * * * *
(a) * * *
(5) Subject to the same emission standards, or FEL in the case of
cold temperature NMHC or NMOG+NOX standards, except that a
manufacturer may request to group vehicles into the same test group as
vehicles subject to more stringent standards, so long as all the
vehicles within the test group are certified to the most stringent
standards applicable to any vehicle within that test group. For
example, manufacturers may include medium-duty vehicles at or below
22,000 pounds GCWR in the same test group with medium-duty vehicles
above 22,000 pounds GCWR, but all vehicles included in the test group
are then subject to the off-cycle emission standards and testing
requirements described in Sec. 86.1811-27(e). Light-duty trucks and
light-duty vehicles may be included in the same test group if all
vehicles in the test group are subject to the same criteria exhaust
emission standards.
* * * * *
0
28. Amend Sec. 86.1828-01 by revising paragraph (e) to read as
follows:
Sec. 86.1828-01 Emission data vehicle selection.
* * * * *
(e) Alternative vehicle configurations. The manufacturer may use
good engineering judgment to select an equivalent or worst-case vehicle
configuration in lieu of testing the vehicle selected in paragraphs (a)
through (c) of this section. Carryover data satisfying the provisions
of Sec. 86.1839 may also be used in lieu of testing the vehicle
configuration selected in paragraphs (a) through (c) of this section.
* * * * *
0
29. Amend Sec. 86.1829-15 by:
0
a. Revising paragraph (d)(3);
0
b. Removing and reserving paragraph (d)(6); and
0
c. Revising paragraph (d)(8).
The revisions read as follows:
Sec. 86.1829-15 Durability and emission testing requirements;
waivers.
* * * * *
(d) * * *
(3) Manufacturers may omit PM measurements for fuel economy testing
conducted in addition to the testing needed to demonstrate compliance
with the PM emission standards.
* * * * *
(8) Manufacturers may provide a statement in the application for
certification that medium-duty vehicles above 22,000 pounds GCWR comply
with the off-cycle emission standards in Sec. 86.1811-27(e) for all
normal operation and use when tested as specified. Describe in the
application for certification under Sec. 86.1844-01(d)(8) any relevant
testing, engineering analysis, or other information in sufficient
detail to support the statement. We may direct you to include emission
measurements representing typical engine in-use operation at a range of
ambient conditions. For example, we may specify certain transient and
steady-state engine operation that is typical for your vehicles. Also
describe the procedure you used to determine a reference brake-specific
CO2 emission rate, eCO2FTP, under Sec. 86.1845-
04(h)(6).
* * * * *
0
30. Amend Sec. 86.1831-01 by revising paragraphs (a)(3) and (c)(2) to
read as follows:
Sec. 86.1830-01 Acceptance of vehicles for emission testing.
(a) * * *
(3) Test vehicles must have air conditioning installed and
operational if that vehicle configuration is available with air
conditioning. Optional equipment must be installed or represented on
test vehicles according to the provisions of Sec. 86.1832-01.
* * * * *
(c) * * *
(2) Within a durability group, the manufacturer may alter any
emission data vehicle (or other vehicles such as current or previous
model year emission data vehicles, running change vehicles, fuel
economy data vehicles, and development vehicles) in lieu of building a
new test vehicle providing that the modification will not impact the
representativeness of the vehicle's test results. Manufacturers shall
use good engineering judgment in making such determinations.
Development vehicles which were used to develop the calibration
selected for emission data testing may not be used as the EDV for that
vehicle configuration. Vehicles from outside the durability group may
be altered with advance approval of the Administrator.
* * * * *
0
31. Amend Sec. 86.1835-01 by revising paragraphs (a)(4), (b)(3), and
(c) to read as follows:
Sec. 86.1835-01 Confirmatory certification testing.
(a) * * *
(4) Retesting for fuel economy may be conducted under the
provisions of 40 CFR 600.008-08.
(b) * * *
(3) For light-duty vehicles, light-duty trucks, and medium-duty
passenger vehicles the manufacturer shall conduct a retest of the FTP
or highway test if the difference between the fuel economy of the
confirmatory test and the original manufacturer's test equals or
exceeds three percent (or such lower percentage to be applied
consistently to all manufacturer conducted confirmatory testing as
requested by the manufacturer and approved by the Administrator).
(i) For use in the fuel economy program described in 40 CFR part
600, the manufacturer may, in lieu of conducting a retest, accept as
official the lower of the original and confirmatory test fuel economy
results.
(ii) The manufacturer shall conduct a second retest of the FTP or
highway test if the fuel economy difference between the second
confirmatory test and the original manufacturer test equals or exceeds
three percent (or such lower percentage as requested by the
manufacturer and approved by the Administrator) and the fuel economy
difference between the second confirmatory test and the first
confirmatory test equals or exceeds three percent (or such lower
percentage as requested by the manufacturer and approved by the
Administrator). In lieu of conducting a second retest, the manufacturer
may accept as official (for use in the fuel economy program) the lowest
fuel economy of the original test, the first confirmatory test, and the
second confirmatory test fuel economy results.
(c) Official test determination. (1) Whenever the Administrator or
the manufacturer conducts a confirmatory test segment on a test
vehicle, the results of that test segment, unless subsequently
invalidated by the Administrator, shall comprise the official data for
that test segment for the vehicle at the prescribed test point and the
manufacturer's original test data for that test segment for that
prescribed test point shall not be used in determining compliance with
emission standards.
(i) If the Administrator or the manufacturer conducts more than one
passing, valid, confirmatory test, the results from the first passing,
valid confirmatory test shall be considered official and used in
determining compliance with emission standards.
(ii) Official test results for fuel economy are determined in
accordance with the provisions of Sec. 600.008-08 of this chapter.
(iii) The Administrator may stop a test after any evaporative test
segment and use as official data any valid results obtained up to that
point in the test, as described in subpart B of this part.
(2) Whenever the Administrator or the manufacturer does not conduct
a
[[Page 36333]]
confirmatory test on a test vehicle at a test point, the manufacturer's
original test data will be accepted as the official data for that
point.
(i) If the Administrator makes a determination based on testing
under paragraph (a) of this section (or other appropriate correlation
test data), that there is a lack of correlation between the
manufacturer's test equipment or procedures and the test equipment or
procedures used by the Administrator, no manufacturer's test data will
be accepted for purposes of certification until the reasons for the
lack of correlation are determined and the validity of the data is
established by the manufacturer.
(ii) If the Administrator has reasonable basis to believe that any
test data submitted by the manufacturer is not accurate or has been
obtained in violation of any provisions of this subpart, the
Administrator may refuse to accept that data as the official data
pending retesting or submission of further information.
(iii) If the manufacturer conducts more than one test on an
emission data vehicle in the same vehicle configuration (excluding
confirmatory tests run under paragraph (b) of this section), the data
from the last test in that series of tests on that vehicle, will
constitute the official data.
* * * * *
Sec. 86.1838-01 [Amended]
0
32. Amend Sec. 86.1838-01 by removing and reserving paragraph
(b)(1)(i)(B).
0
33. Revise Sec. 86.1839-01 to read as follows:
Sec. 86.1839-01 Carryover of certification and battery monitoring
data.
(a) In lieu of testing an emission-data or durability vehicle
selected under Sec. 86.1822, Sec. 86.1828, or Sec. 86.1829, and
submitting data therefrom, a manufacturer may submit exhaust emission
data, evaporative emission data and/or refueling emission data, as
applicable, on a similar vehicle for which certification has been
obtained or for which all applicable data required under Sec. 86.1845
has previously been submitted. To be eligible for this provision, the
manufacturer must use good engineering judgment and meet the following
criteria:
(1) In the case of durability data, the manufacturer must determine
that the previously generated durability data represent a worst case or
equivalent rate of deterioration for all applicable emission
constituents compared to the vehicle configuration selected for
durability demonstration. Prior to certification, the Administrator may
require the manufacturer to provide data showing that the distribution
of catalyst temperatures of the selected durability vehicle
configuration is effectively equivalent or lower than the distribution
of catalyst temperatures of the vehicle configuration which is the
source of the previously generated data.
(2) In the case of emission data, the manufacturer must determine
that the previously generated emissions data represent a worst case or
equivalent level of emissions for all applicable emission constituents
compared to the vehicle configuration selected for emission compliance
demonstration.
(b) In lieu of using newly aged hardware on an EDV as allowed under
the provisions of Sec. 86.1823-08(f)(2), a manufacturer may use
similar hardware aged for an EDV previously submitted, provided that
the manufacturer determines that the previously aged hardware
represents a worst case or equivalent rate of deterioration for all
applicable emission constituents for durability demonstration.
Sec. 86.1841-01 [Amended]
0
34. Amend Sec. 86.1841-01 by removing and reserving paragraph (a)(3).
0
35. Amend Sec. 86.1844-01 by:
0
a. Removing and reserving paragraph (d)(7)(iv);
0
b. Revising paragraph (d)(15);
0
c. Removing and reserving paragraph (d)(20); and
0
d. Revising paragraphs (e)(1) and (3).
The revisions read as follows:
Sec. 86.1844-01 Information requirements: Application for
certification and submittal of information upon request.
* * * * *
(d) * * *
(15) For vehicles with fuel-fired heaters, describe the control
system logic of the fuel-fired heater, including an evaluation of the
conditions under which it can be operated and an evaluation of the
possible operational modes and conditions under which evaporative
emissions can exist. Use good engineering judgment to establish an
estimated exhaust emission rate from the fuel-fired heater in grams per
mile for each pollutant subject to a fleet average standard. Adjust
fleet average compliance calculations in Sec. Sec. 86.1861 and 86.1864
as appropriate to account for emissions from fuel-fired heaters.
Describe the testing used to establish the exhaust emission rate.
* * * * *
(e) * * *
(1) Identify all emission-related components. Also identify
software, AECDs, and other elements of design that are used to control
exhaust or evaporative/refueling emissions. Identify the emission-
related components by part number. Identify software by part number or
other convention, as appropriate. Organize part numbers by engine code
or other similar classification scheme.
* * * * *
(3) Identification and description of all vehicles covered by each
certificate of conformity to be produced and sold within the U.S. The
description must be sufficient to identify whether any given in-use
vehicle is, or is not, covered by a given certificate of conformity,
the test group and the evaporative/refueling family to which it belongs
and the standards that are applicable to it, by matching readily
observable vehicle characteristics and information given in the
emission control information label (and other permanently attached
labels) to indicators in the Part 1 Application. For example, the
description must include any components or features that contribute to
measured or demonstrated control of emissions for meeting exhaust or
evaporative/refueling standards under this subpart. In addition, the
description must be sufficient to determine for each vehicle covered by
the certificate, all appropriate test parameters and any special test
procedures necessary to conduct an official certification exhaust or
evaporative emission test as was required by this subpart to
demonstrate compliance with applicable emission standards. The
description shall include, but is not limited to, information such as
model name, vehicle classification (light-duty vehicle, light-duty
truck, or complete heavy-duty vehicle), sales area, engine
displacement, engine code, transmission type, tire size and parameters
necessary to conduct exhaust emission tests such as equivalent test
weight, curb and gross vehicle weight, test horsepower (with and
without air conditioning adjustment), coast down time, shift schedules,
cooling fan configuration, etc. and evaporative tests such as canister
working capacity, canister bed volume, and fuel temperature profile.
Actual values must be provided for all parameters.
* * * * *
0
36. Amend Sec. 86.1845-04 by:
0
a. Revising paragraphs (b)(5)(i) and (c)(5)(i);
0
b. Removing and reserving paragraph (g); and
0
d. Revising paragraph (h)(6).
The revisions read as follows:
Sec. 86.1845-04 Manufacturer in-use verification testing
requirements.
* * * * *
[[Page 36334]]
(b) * * *
(5) Testing. (i) Each test vehicle of a test group shall be tested
in accordance with the FTP and the US06 as described in subpart B of
this part, when such test vehicle is tested for compliance with
applicable exhaust emission standards under this subpart.
* * * * *
(c) * * *
(5) Testing. (i) Each test vehicle shall be tested in accordance
with the FTP and the US06 as described in subpart B of this part when
such test vehicle is tested for compliance with applicable exhaust
emission standards under this subpart. One test vehicle from each test
group shall be tested over the FTP at high altitude. The test vehicle
tested at high altitude is not required to be one of the same test
vehicles tested at low altitude. The test vehicle tested at high
altitude is counted when determining the compliance with the
requirements shown in Table S04-06 and Table S04-07 (tables 1 and 2 to
paragraph (b)(3) of this section) or the expanded sample size as
provided for in this paragraph (c).
* * * * *
(h) * * *
(6) Determine a reference CO2 emission rate,
eCO2FTP, as described in 40 CFR 1036.235(b) or based on
measured values from any chassis FTP driving cycles under 40 CFR part
1066, subpart I, that is used for reporting data from an emission data
vehicle or a fuel economy data vehicle, as follows:
Equation 1 to Paragraph (h)(6)
[GRAPHIC] [TIFF OMITTED] TP01AU25.000
Where:
mCO2FTP = CO2 emission mass in
grams emitted over the FTP driving cycle.
dFTP = measured driving distance in miles.
WFTP = work performed over the FTP.
[GRAPHIC] [TIFF OMITTED] TP01AU25.001
i = an indexing variable that represents a 1 Hz OBD time counter
over the course of the FTP drive.
N = total number of measurements over the FTP duty cycle = 1874.
fn = engine speed for each point, i, starting from the
start of the FTP drive at i = 1, collected from OBD PID $0C.
T = engine torque in N[middot]m for each point, i, starting from i =
1. Calculate T by subtracting Friction Torque (PID $8E) from
Indicated Torque (PID $62) (both PIDs are percentages) and then
multiplying by the reference torque (PID $63). Set torque to zero if
friction torque is greater than indicated torque.
[Delta]t = 1/frecord.
frecord = the data recording frequency.
Example
mCO2FTP = 10,961 g
N = 1874
f1 = 687.3 r/min = 71.97 rad/s
f2 = 689.7 r/min = 72.23 rad/s
T1 = 37.1 ft[middot]lbf = 50.3 N[middot]m
T2 = 37.2 ft[middot]lbf = 50.4 N[middot]m
frecord = 1 Hz
[Delta]t = \1/1\ = 1 s = 0.000277 hr
WFTP = 71.97 [middot] 50.3 [middot] 1.0 + 72.23 [middot]
50.4 [middot] 1.0 + [middot] [middot] [middot]
[fnof]n1874 [middot] T1874 [middot]
[Delta]t1874
WFTP = 53,958,852 W[middot]s = 20.1 hp[middot]hr
[GRAPHIC] [TIFF OMITTED] TP01AU25.002
eCO2FTP = 545.3 g/hp[middot]hr
* * * * *
0
37. Amend Sec. 86.1846-01 by:
0
a. Revising paragraph (a); and
0
b. Removing and reserving paragraph (b)(2).
The revision read as follows:
Sec. 86.1846-01 Manufacturer in-use confirmatory testing
requirements.
(a) General requirements.
(1) Manufacturers must test, or cause testing to be conducted,
under this section when the emission levels shown by a test group
sample from testing under Sec. 86.1845 exceeds the criteria specified
in paragraph (b) of this section. The testing required under this
section applies separately to each test group and at each test point
(low and high mileage) that meets the specified criteria. The testing
requirements apply separately for each model year.
(2) The provisions of Sec. 86.1845-04(a)(3) regarding fuel sulfur
effects apply equally to testing under this section.
* * * * *
Sec. 86.1848-10 [Amended]
0
38. Amend Sec. 86.1848-10 by removing and reserving paragraph (c)(9).
0
39. Amend Sec. 86.1854-12 by revising paragraph (a)(2)(iv) to read as
follows:
Sec. 86.1854-12 Prohibited acts.
(a) * * *
(2) * * *
(iv) For a person to fail to establish or maintain records as
required under Sec. Sec. 86.1844, 86.1862, and 86.1864 with regard to
vehicles.
* * * * *
0
40. Revise and republish Sec. 86.1861-17 to read as follows:
Sec. 86.1861-17 How do the NMOG + NOX and evaporative emission credit
programs work?
You may use emission credits for purposes of certification to show
compliance with the applicable fleet average NMOG+NOX
standards from Sec. Sec. 86.1811 and 86.1816 and the fleet average
evaporative emission standards from Sec. 86.1813 as described in 40
CFR part 1036, subpart H, with certain exceptions and clarifications as
specified in this section. MDPVs are subject to the same provisions of
this section that apply to LDT4.
(a) Calculate emission credits as described in this paragraph (a)
instead of using the provisions of 40 CFR 1036.705. Calculate positive
or negative emission credits relative to the applicable fleet average
standard. Calculate positive emission credits if your fleet average
level is below the standard. Calculate negative emission credits if
your fleet average value is above the standard. Calculate credits
separately for each applicable fleet average standard and calculate
total credits for each averaging set as specified in paragraph (b) of
this section. Convert units from mg/mile to g/mile as needed for
performing calculations. Calculate emission credits using the following
equation, rounded to the nearest whole number:
Equation 1 to Paragraph (a)
Emission credit = Volume [middot] [Fleet average standard-Fleet average
value]
Where:
[[Page 36335]]
Emission credit = The positive or negative credit for each discrete
fleet average standard, in units of vehicle-grams per mile for
NMOG+NOX and vehicle-grams per test for evaporative
emissions.
Volume = Sales volume in a given model year from the collection of
test groups or evaporative families covered by the fleet average
value, as described in Sec. 86.1860.
(b) The following restrictions apply instead of those specified in
40 CFR 1036.740:
(1) Except as specified in paragraph (b)(2) of this section,
emission credits may be exchanged only within an averaging set, as
follows:
(i) HDV represent a separate averaging set with respect to all
emission standards.
(ii) Except as specified in paragraph (b)(1)(iii) of this section,
light-duty program vehicles represent a single averaging set with
respect to all emission standards. Note that FTP and SFTP credits for
Tier 3 vehicles are not interchangeable.
(iii) LDV and LDT1 certified to standards based on a useful life of
120,000 miles and 10 years together represent a single averaging set
with respect to NMOG+NOX emission standards. Note that FTP
and SFTP credits for Tier 3 vehicles are not interchangeable.
(iv) The following separate averaging sets apply for evaporative
emission standards:
(A) LDV and LDT1 together represent a single averaging set.
(B) LDT2 represents a single averaging set.
(C) HLDT represents a single averaging set.
(D) HDV represents a single averaging set.
(2) You may exchange evaporative emission credits across averaging
sets as follows if you need additional credits to offset a deficit
after the final year of maintaining deficit credits as allowed under
paragraph (c) of this section:
(i) You may exchange LDV/LDT1 and LDT2 emission credits.
(ii) You may exchange HLDT and HDV emission credits.
(3) Except as specified in paragraph (b)(4) of this section,
credits expire after five years. For example, credits you generate in
model year 2018 may be used only through model year 2023.
(4) For the Tier 3 declining fleet average FTP and SFTP emission
standards for NMOG+NOX described in Sec. 86.1811-17(b)(8),
credits generated in model years 2017 through 2024 expire after eight
years, or after model year 2030, whichever comes first; however, these
credits may not be traded after five years. This extended credit life
also applies for small-volume manufacturers generating credits under
Sec. 86.1811-17(h)(1) in model years 2022 through 2024. Note that the
longer credit life does not apply for heavy-duty vehicles, for vehicles
certified under the alternate phase-in described in Sec. 86.1811-
17(b)(9), or for vehicles generating early Tier 3 credits under Sec.
86.1811-17(b)(11) in model year 2017.
(5) Tier 3 credits for NMOG+NOX may be used to
demonstrate compliance with Tier 4 standards without adjustment, except
as specified in Sec. 86.1811-27(b)(6)(ii).
(6) A manufacturer may generate NMOG+NOX credits from
model year 2027 through 2032 electric vehicles that qualify as MDPV and
use those credits for certifying medium-duty vehicles, as follows:
(i) Calculate generated credits separately for qualifying vehicles.
Calculate generated credits by multiplying the applicable standard for
light-duty program vehicles by the sales volume of qualifying vehicles
in a given model year.
(ii) Apply generated credits to eliminate any deficit for light-
duty program vehicles before using them to certify medium-duty
vehicles.
(iii) Apply the credit provisions of this section as specified,
except that you may not buy or sell credits generated under this
paragraph (b)(6).
(iv) Describe in annual credit reports how you are generating
certain credit quantities under this paragraph (b)(6). Also describe in
your end of year credit report how you will use those credits for
certifying light-duty program vehicles or medium-duty vehicles in a
given model year.
(c) The credit-deficit provisions 40 CFR 1036.745 apply to the
NMOG+NOX and evaporative emission standards for Tier 3 and
Tier 4 vehicles. Credit-deficit provisions are not affected by the
transition from Tier 3 to Tier 4 standards.
(d) The reporting and recordkeeping provisions of Sec. 86.1862
apply instead of those specified in 40 CFR 1036.730 and 1036.735.
(e) The provisions of 40 CFR 1036.625 do not apply.
Sec. Sec. 86.1865-12, 86.1866-12, 86.1867-12, and 86.1867-
31 [Removed]
0
41. Remove Sec. Sec. 86.1865-12, 86.1866-12, 86.1867-12, and 86.1867-
31.
0
42. Amend Sec. 86.1868-12 by:
0
a. Revising the introductory text and paragraph (c);
0
b. Removing and reserving paragraph (d); and
0
c. Revising paragraphs (g) introductory text and (g)(3) introductory
text.
to read as follows:
Sec. 86.1868-12 CO2 credits for improving the efficiency of air
conditioning systems.
The regulation at 40 CFR 600.510 describes how manufacturers may
calculate fuel consumption improvement values based on improvements to
air conditioning efficiency. This section describes how to calculate
credits to determine the average fuel economy for comparing to the
Corporate Average Fuel Economy standard. The provisions of this section
do not apply for medium-duty vehicles. Credits shall be calculated
according to this section for each air conditioning system that the
manufacturer is using to generate credits. Manufacturers must validate
credits under this section based on testing as described in paragraph
(g) of this section. Starting in model year 2027, manufacturers may
generate credits under this section only for vehicles propelled by
internal combustion engines.
* * * * *
(c) The total efficiency credits generated by an air conditioning
system shall be calculated in megagrams separately for passenger
automobiles and light trucks according to the following formula:
Equation 1 to Paragraph (c)
[GRAPHIC] [TIFF OMITTED] TP01AU25.003
Where:
Credit = the air conditioning efficiency credit in grams per mile
determined in paragraph (b) of this section. Starting in
[[Page 36336]]
model year 2027, multiply the credit value for PHEV by (1-UF), where
UF = the fleet utility factor established under 40 CFR 600.116-
12(c)(1) or (c)(10)(iii) (weighted 55 percent city, 45 percent
highway.
Production = The total number of passenger automobiles or light
trucks, whichever is applicable, produced with the air conditioning
system to which to the efficiency credit value from paragraph (b) of
this section applies.
VLM = vehicle lifetime miles, which for passenger automobiles shall
be 195,264 and for light trucks shall be 225,865.
* * * * *
(g) For AC17 validation testing and reporting requirements,
manufacturers must validate air conditioning efficiency credits by
using the AC17 Test Procedure in 40 CFR 1066.845 as follows:
* * * * *
(3) For the first model year for which an air conditioning system
is expected to generate credits, the manufacturer must select for
testing the projected highest-selling vehicle configuration within each
combination of vehicle platform and air conditioning system (as those
terms are defined in Sec. 86.1803). The manufacturer must test at
least one unique air conditioning system within each vehicle platform
in a model year, unless all unique air conditioning systems within a
vehicle platform have been previously tested. A unique air conditioning
system design is a system with unique or substantially different
component designs or types and/or system control strategies (e.g.,
fixed-displacement vs. variable displacement compressors, orifice tube
vs. thermostatic expansion valve, single vs. dual evaporator, etc.). In
the first year of such testing, the tested vehicle configuration shall
be the highest production vehicle configuration within each platform.
In subsequent model years the manufacturer must test other unique air
conditioning systems within the vehicle platform, proceeding from the
highest production untested system until all unique air conditioning
systems within the platform have been tested, or until the vehicle
platform experiences a major redesign. Whenever a new unique air
conditioning system is tested, the highest production vehicle
configuration using that system shall be the vehicle selected for
testing. Credits may continue to be generated by the air conditioning
system installed in a vehicle platform provided that:
* * * * *
0
43. Amend Sec. 86.1869-12 by revising the introductory text and
paragraphs (a), (b)(1) introductory text, (b)(2) introductory text,
(b)(2)(v), (c) introductory text, and (e)(2)(i) to read as follows:
Sec. 86.1869-12 CO2 credits for off-cycle CO2 reducing technologies.
The regulation at 40 CFR 600.510 describes how manufacturers may
calculate fuel consumption improvement values based on vehicle
improvements that are not reflected in testing to demonstrate
compliance with exhaust emission standards. This section describes how
to calculate credits to determine the average fuel economy for
comparing to the Corporate Average Fuel Economy standard through model
year 2032. The provisions of this section do not apply for medium-duty
vehicles. Manufacturers may no longer generate credits under this
section starting in model year 2027 for vehicles deemed to have zero
tailpipe emissions and in model year 2033 for all other vehicles.
Manufacturers may no longer generate credits under paragraphs (c) and
(d) of this section for any type of vehicle starting in model year
2027.
(a) Manufacturers may generate credits for CO2-reducing
technologies where the CO2 reduction benefit of the
technology is not adequately captured on the Federal Test Procedure
and/or the Highway Fuel Economy Test such that the technology would not
be otherwise installed for purposes of meeting Corporate Average Fuel
Economy standards. These technologies must have a measurable,
demonstrable, and verifiable real-world CO2 reduction that
occurs outside the conditions of the Federal Test Procedure and the
Highway Fuel Economy Test. These optional credits are referred to as
``off-cycle'' credits. The technologies must not be integral or
inherent to the basic vehicle design, such as engine, transmission,
mass reduction, passive aerodynamic design, and tire technologies.
Technologies installed for non-off-cycle emissions related reasons are
also not eligible as they would be considered part of the baseline
vehicle design. The technology must not be inherent to the design of
occupant comfort and entertainment features except for technologies
related to reducing passenger air conditioning demand and improving air
conditioning system efficiency. Notwithstanding the provisions of this
paragraph (a), off-cycle menu technologies included in paragraph (b) of
this section remain eligible for credits. Off-cycle technologies used
to generate emission credits are considered emission-related components
subject to applicable requirements and must be demonstrated to be
effective for the full useful life of the vehicle. Unless the
manufacturer demonstrates that the technology is not subject to in-use
deterioration, the manufacturer must account for the deterioration in
their analysis. Durability evaluations of off-cycle technologies may
occur at any time throughout a model year, provided that the results
can be factored into the data provided in the model year report. Off-
cycle credits may not be approved for crash-avoidance technologies,
safety critical systems or systems affecting safety-critical functions,
or technologies designed for the purpose of reducing the frequency of
vehicle crashes. Off-cycle credits may not be earned for technologies
installed on a motor vehicle to attain compliance with any vehicle
safety standard or any regulation set forth in Title 49 of the Code of
Federal Regulations. The manufacturer must use one of the three options
specified in this section to establish off-cycle credits under this
section.
(b) * * *
(1) The manufacturer may generate off-cycle credits for certain
technologies as specified in this paragraph (b)(1). Technology
definitions are in paragraph (b)(4) of this section. Calculated credit
values shall be rounded to the nearest 0.1 grams/mile.
* * * * *
(2) The maximum allowable off-cycle credit for the combined
passenger automobile and light truck fleet attributable to use of the
default credit values in paragraph (b)(1) of this section is specified
in paragraph (b)(2)(v) of this section. If the total of the off-cycle
credit values from paragraph (b)(1) of this section does not exceed the
specified off-cycle credit cap for any passenger automobile or light
truck in a manufacturer's fleet, then the total off-cycle credits may
be calculated according to paragraph (f) of this section. If the total
of the off-cycle credit values from paragraph (b)(1) of this section
exceeds the specified off-cycle credit cap for any passenger automobile
or light truck in a manufacturer's fleet, then the gram per mile
decrease for the combined passenger automobile and light truck fleet
must be determined according to paragraph (b)(2)(ii) of this section to
determine whether the applicable limitation has been exceeded.
* * * * *
(v) The manufacturer's combined passenger automobile and light
truck fleet average off-cycle credits attributable to use of the
default credit values in paragraph (b)(1) of this section may not
exceed the following specific values:
[[Page 36337]]
------------------------------------------------------------------------
Off-cycle
Model year credit cap
(g/mile)
------------------------------------------------------------------------
(A) 2023-2026.............................................. 15
(B) 2027-2030.............................................. 10
(C) 2031................................................... 8.0
(D) 2032................................................... 6.0
------------------------------------------------------------------------
* * * * *
(c) Technology demonstration using EPA 5-cycle methodology. To
demonstrate an off-cycle technology and to determine off-cycle credits
using the EPA 5-cycle methodology, the manufacturer shall determine the
off-cycle city/highway combined carbon-related exhaust emissions
benefit by using the EPA 5-cycle methodology described in 40 CFR part
600. This method may not be used for technologies that include elements
(e.g., driver-selectable systems) that require additional analyses,
data collection, projections, or modeling, or other assessments to
determine a national average benefit of the technology. Testing shall
be performed on a representative vehicle, selected using good
engineering judgment, for each model type for which the credit is being
demonstrated. The emission benefit of a technology is determined by
testing both with and without the off-cycle technology operating. If a
specific technology is not expected to change emissions on one of the
five test procedures, the manufacturer may submit an engineering
analysis to the EPA that demonstrates that the technology has no
effect. If EPA concurs with the analysis, then multiple tests are not
required using that test procedure; instead, only one of that test
procedure shall be required--either with or without the technology
installed and operating--and that single value will be used for all of
the 5-cycle weighting calculations. Multiple off-cycle technologies may
be demonstrated on a test vehicle. The manufacturer shall conduct the
following steps and submit all test data to the EPA.
* * * * *
(e) * * *
(2) * * *
(i) A detailed description of the off-cycle technology and how it
functions to improve fuel economy under conditions not represented on
the FTP and HFET.
* * * * *
Sec. 86.1870-12 [Removed]
0
44. Remove Sec. 86.1870-12.
PART 600--FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF
MOTOR VEHICLES
0
45. The authority citation for part 600 continues to read as follows:
Authority: 49 U.S.C. 32901--23919q, Pub. L. 109-58.
Sec. 600.001 [Amended]
0
46. Amend Sec. 600.001 by removing the last sentence in paragraph (a)
and the last two sentences in paragraph (c).
0
47. Amend Sec. 600.002 by:
0
a. Revising the definitions of ``Carbon-related exhaust emissions
(CREE)'' and ``Engine code'';
0
b. Removing the definition of ``Footprint''; and
0
c. Revising the definitions of ``Medium-duty passenger vehicle
(MDPVFE)'', ``Subconfiguration'', and ``Vehicle
configuration''.
The revisions read as follows:
Sec. 600.002 Definitions.
* * * * *
Carbon-related exhaust emissions (CREE) means the summation of the
carbon-containing constituents of the exhaust emissions, with each
constituent adjusted by a coefficient representing the carbon weight
fraction of each constituent relative to the CO2 carbon
weight fraction, as specified in Sec. 600.113.
* * * * *
Engine code means a unique combination, within a test group (as
defined in Sec. 86.1803 of this chapter), of displacement, fuel
injection (or carburetion or other fuel delivery system), calibration,
distributor calibration, choke calibration, auxiliary emission control
devices, and other engine and emission control system components
specified by the Administrator. For electric vehicles, engine code
means a unique combination of manufacturer, electric traction motor,
motor configuration, motor controller, and energy storage device.
* * * * *
Medium-duty passenger vehicle (MDPVFE) means any motor
vehicle rated at more than 8,500 pounds GVWR and less than 10,000
pounds GVWR that is designed primarily to transport passengers, but
does not include a vehicle that--
(1) Is an ``incomplete truck,'' meaning any truck which does not
have the primary load carrying device or container attached when it is
first sold as a vehicle; or
(2) Has a seating capacity of more than 12 persons; or
(3) Is designed for more than 9 persons in seating rearward of the
driver's seat; or
(4) Is equipped with an open cargo area (for example, a pick-up
truck box or bed) of 72.0 inches in interior length or more. A covered
box not readily accessible from the passenger compartment will be
considered an open cargo area for purposes of this definition. (See
paragraph (1) of the definition of medium-duty passenger vehicle at 40
CFR 86.1803-01).
* * * * *
Subconfiguration means a unique combination within a vehicle
configuration of equivalent test weight, road-load horsepower, and any
other operational characteristics or parameters which the Administrator
determines may significantly affect fuel economy or CO2
emissions within a vehicle configuration.
* * * * *
Vehicle configuration means a unique combination of basic engine,
engine code, inertia weight class, transmission configuration, and axle
ratio within a base level.
* * * * *
0
48. Amend Sec. 600.006 by revising paragraphs (c)(5), (e), and
(g)(3)(ii) to read as follows:
Sec. 600.006 Data and information requirements for fuel economy data
vehicles.
* * * * *
(c) * * *
(5) Starting with the 2012 model year, the data submitted according
to paragraphs (c)(1) through (4) of this section shall include total
HC, CO, CO2, and, where applicable for alternative fuel
vehicles, CH3OH, C2H5OH,
C2H4O, HCHO, NMHC and CH4.
* * * * *
(e) In lieu of submitting actual data from a test vehicle, a
manufacturer may provide fuel economy and CO2 emission
values derived from a previously tested vehicle, where the fuel economy
and CO2 emissions are expected to be equivalent (or less
fuel-efficient and with higher CO2 emissions). Additionally,
in lieu of submitting actual data from a test vehicle, a manufacturer
may provide fuel economy and CO2 emission values derived
from an analytical expression, e.g., regression analysis. In order for
fuel economy and CO2 emission values derived from analytical
methods to be accepted, the expression (form and coefficients) must
have been approved by the Administrator.
* * * * *
(g) * * *
[[Page 36338]]
(3) * * *
(ii)(A) The manufacturer shall adjust all CO2 test data
generated by vehicles with engine-drive system combinations with more
than 6,200 miles by using the following equation:
ADJ4,000mi = TEST[0.979 + 5.25 [middot] 10-6
[middot] (mi)]
Where:
ADJ4,000mi = CO2 emission data adjusted to
4,000-mile test point.
TEST = Tested emissions value of CO2 in grams per mile.
mi = System miles accumulated at the start of the test rounded to
the nearest whole mile.
(B) Emissions test values and results used and determined in the
calculations in this paragraph (g)(3)(ii) shall be rounded in
accordance with Sec. 86.1837 of this chapter as applicable. Round
results to the nearest gram per mile.
* * * * *
0
49. Amend Sec. 600.007 by revising paragraphs (b)(5) and (6), (c), and
(f) introductory text to read as follows:
Sec. 600.007 Vehicle acceptability.
* * * * *
(b) * * *
(5) The calibration information submitted under Sec. 600.006(b)
must be representative of the vehicle configuration for which the fuel
economy and CO2 emission data were submitted.
(6) Any vehicle tested for fuel economy or CO2 emissions
must be representative of a vehicle which the manufacturer intends to
produce under the provisions of a certificate of conformity.
* * * * *
(c) If, based on review of the information submitted under Sec.
600.006(b), the Administrator determines that a fuel economy data
vehicle meets the requirements of this section, the fuel economy data
vehicle will be judged to be acceptable and fuel economy data from that
fuel economy data vehicle will be reviewed pursuant to Sec. 600.008.
* * * * *
(f) All vehicles used to generate fuel economy data, and for which
emission standards apply, must be covered by a certificate of
conformity under part 86 of this chapter before:
* * * * *
0
50. Amend Sec. 600.008 by revising the section heading and paragraph
(a)(1)(ii) to read as follows:
Sec. 600.008 Review of fuel economy and CO2 emission data, testing by
the Administrator.
(a) * * *
(1) * * *
(ii) The evaluations, testing, and test data described in this
section pertaining to fuel economy shall also be performed for
CO2 emissions, except that CO2 emissions shall be
arithmetically averaged instead of harmonically averaged, and in cases
where the manufacturer selects the lowest of several fuel economy
results to represent the vehicle, the manufacturer shall select the
CO2 emission value from the test results associated with the
lowest selected fuel economy results.
* * * * *
0
51. Amend Sec. 600.010 by revising paragraphs (c)(1)(ii) and (d) to
read as follows:
Sec. 600.010 Vehicle test requirements and minimum data requirements.
* * * * *
(c) * * *
(1) * * *
(ii)(A) FTP and HFET data from the highest projected model year
sales subconfiguration within the highest projected model year sales
vehicle configuration for each base level, and
(B) If required under Sec. 600.115, for 2011 and later model year
vehicles, US06, SC03 and cold temperature FTP data from the highest
projected model year sales subconfiguration within the highest
projected model year sales vehicle configuration for each base level.
Manufacturers may optionally generate this data for any 2008 through
2010 model years, and, 2011 and later model year vehicles, if not
otherwise required.
* * * * *
(d) Minimum data requirements for the manufacturer's average fuel
economy. For the purpose of calculating the manufacturer's average fuel
economy under Sec. 600.510, the manufacturer shall submit FTP (city)
and HFET (highway) test data representing at least 90 percent of the
manufacturer's actual model year production, by vehicle configuration,
for each category identified for calculation under Sec. 600.510-08(a)
or Sec. 600.510-12(a)(1).
0
52. Revise the heading of subpart B as set forth above.
0
53. Amend Sec. 600.101 by revising paragraph (a)(2) and removing and
reserving paragraph (b)(2). The revision reads as follows:
Sec. 600.101 Testing overview.
* * * * *
(a) * * *
(2) Calculate fuel economy values for vehicle subconfigurations,
configurations, base levels, and model types as described in Sec. Sec.
600.206 and 600.208. Calculate fleet average values for fuel economy as
described in Sec. 600.510. Note that Sec. 600.510(c) describes how to
use CREE to determine fuel consumption improvement values for specific
cases.
* * * * *
0
54. Amend Sec. 600.111-08 by revising paragraph (h) to read as
follows:
Sec. 600.111-08 Test procedures.
* * * * *
(h) Special test procedures. We may allow or require you to use
procedures other than those specified in this section as described in
40 CFR 1066.10(c). For example, special test procedures may be used for
advanced technology vehicles, including, but not limited to fuel cell
vehicles, hybrid electric vehicles using hydraulic energy storage, and
vehicles equipped with hydrogen internal combustion engines.
Additionally, we may conduct fuel economy and exhaust emission testing
using the special test procedures approved for a specific vehicle.
0
55. Amend Sec. 600.113-12 by:
0
a. Revising the section heading, introductory text, and paragraph (g);
0
b. Removing and reserving paragraphs (h)(2), (i)(2), (j)(2), (k)(2),
(l)(2), (m)(2);
0
c. Revising paragraph (n);
0
d. Removing and reserving paragraph (o)(2); and
0
e. Revising paragraph (p).
The revisions read as follows:
Sec. 600.113-12 Fuel economy and CO2 emission calculations for FTP,
HFET, US06, SC03 and cold temperature FTP tests.
The Administrator will use the calculation procedure set forth in
this section for all official EPA testing of vehicles fueled with
gasoline, diesel, alcohol-based or natural gas fuel. The calculations
of the weighted fuel economy values require input of the weighted
grams/mile values for total hydrocarbons (HC), carbon monoxide (CO),
and carbon dioxide (CO2); and, additionally for methanol-
fueled automobiles, methanol (CH3OH) and formaldehyde
(HCHO); and, additionally for ethanol-fueled automobiles, methanol
(CH3OH), ethanol (C2H5OH),
acetaldehyde (C2H4O), and formaldehyde (HCHO);
and additionally for natural gas-fueled vehicles, non-methane
hydrocarbons (NMHC) and methane (CH4). Emissions shall be
determined for the FTP, HFET, US06, SC03, and cold temperature FTP
tests. Additionally, the specific gravity, carbon weight fraction and
net heating value of the test fuel must be determined. The FTP, HFET,
US06, SC03, and cold temperature FTP fuel economy values shall be
calculated as specified in this section. An example
[[Page 36339]]
fuel economy calculation appears in appendix II to this part.
* * * * *
(g) Calculate separate FTP, highway, US06, SC03 and Cold
temperature FTP fuel economy values from the grams/mile values for
total HC, CO, CO2 and, where applicable, CH3OH,
C2H5OH, C2H4O, HCHO, NMHC,
N2O, and CH4, and the test fuel's specific
gravity, carbon weight fraction, net heating value, and additionally
for natural gas, the test fuel's composition.
(1) Emission values for fuel economy calculations. The emission
values (obtained per paragraph (a) through (e) of this section, as
applicable) used in the calculations of fuel economy in this section
shall be rounded in accordance with Sec. 86.1837 of this chapter. The
CO2 values (obtained per this section, as applicable) used
in each calculation of fuel economy in this section shall be rounded to
the nearest gram/mile.
(2) [Reserved]
(h)
(1) For gasoline-fueled automobiles tested on a test fuel specified
in Sec. 86.113 of this chapter, the fuel economy in miles per gallon
is to be calculated using the following equation and rounded to the
nearest 0.1 miles per gallon:
mpg = (5174 x 10\4\ x CWF x SG)/[((CWF x HC) + (0.429 x CO) + (0.273 x
CO2)) x ((0.6 x SG x NHV) + 5471)]
Where:
HC = Grams/mile HC as obtained in paragraph (g)(1) of this section.
CO = Grams/mile CO as obtained in paragraph (g)(1) of this section.
CO2 = Grams/mile CO2 as obtained in paragraph
(g)(1) of this section.
CWF = Carbon weight fraction of test fuel as obtained in paragraph
(f)(1) of this section and rounded according to paragraph (g)(3) of
this section.
NHV = Net heating value by mass of test fuel as obtained in
paragraph (f)(1) of this section and rounded according to paragraph
(g)(3) of this section.
SG = Specific gravity of test fuel as obtained in paragraph (f)(1)
of this section and rounded according to paragraph (g)(3) of this
section.
(2) [Reserved]
(i)
(1) For diesel-fueled automobiles, calculate the fuel economy in
miles per gallon of diesel fuel by dividing 2778 by the sum of three
terms and rounding the quotient to the nearest 0.1 mile per gallon:
(i) (A) 0.866 multiplied by HC (in grams/miles as obtained in
paragraph (g)(1) of this section), or
(B) Zero, in the case of cold FTP diesel tests for which HC was not
collected, as permitted in Sec. 600.113-08(c);
(ii) 0.429 multiplied by CO (in grams/mile as obtained in paragraph
(g)(1) of this section); and
(iii) 0.273 multiplied by CO2 (in grams/mile as obtained
in paragraph (g)(1) of this section).
(2) [Reserved](j)
(1) For methanol-fueled automobiles and automobiles designed to
operate on mixtures of gasoline and methanol, the fuel economy in miles
per gallon of methanol is to be calculated using the following
equation:
mpg = (CWF x SG x 3781.8)/((CWFexHC x HC) + (0.429 x CO) +
(0.273 x CO2) + (0.375 x CH3OH) + (0.400 x HCHO))
Where:
CWF = Carbon weight fraction of the fuel as determined in paragraph
(f)(2)(ii) of this section and rounded according to paragraph (g)(3)
of this section.
SG = Specific gravity of the fuel as determined in paragraph
(f)(2)(i) of this section and rounded according to paragraph (g)(3)
of this section.
CWFexHC = Carbon weight fraction of exhaust hydrocarbons
= CWF as determined in paragraph (f)(2)(ii) of this section and
rounded according to paragraph (g)(3) of this section (for M100
fuel, CWFexHC = 0.866).
HC = Grams/mile HC as obtained in paragraph (g)(1) of this section.
CO = Grams/mile CO as obtained in paragraph (g)(1) of this section.
CO2 = Grams/mile CO2 as obtained in paragraph
(g)(1) of this section.
CH3OH = Grams/mile CH3OH (methanol) as
obtained in paragraph (g)(1) of this section.
HCHO = Grams/mile HCHO (formaldehyde) as obtained in paragraph
(g)(1) of this section.
(2) [Reserved]
(k)
(1) For automobiles fueled with natural gas and automobiles
designed to operate on gasoline and natural gas, the fuel economy in
miles per gallon of natural gas is to be calculated using the following
equation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.004
Where:
mpge = miles per gasoline gallon equivalent of natural
gas.
CWFHC/NG = carbon weight fraction based on the
hydrocarbon constituents in the natural gas fuel as obtained in
paragraph (f)(3) of this section and rounded according to paragraph
(g)(3) of this section.
DNG = density of the natural gas fuel [grams/ft\3\ at 68
[deg]F (20 [deg]C) and 760 mm Hg (101.3 kPa)] pressure as obtained
in paragraph (g)(3) of this section.
CH4, NMHC, CO, and CO2 = weighted mass exhaust
emissions [grams/mile] for methane, non-methane HC, carbon monoxide,
and carbon dioxide as obtained in paragraph (g)(2) of this section.
CWFNMHC = carbon weight fraction of the non-methane HC
constituents in the fuel as determined from the speciated fuel
composition per paragraph (f)(3) of this section and rounded
according to paragraph (g)(3) of this section.
CO2NG = grams of carbon dioxide in the natural gas fuel
consumed per mile of travel.
CO2NG = FCNG x DNG x
WFCO2
Where:
[GRAPHIC] [TIFF OMITTED] TP01AU25.005
= cubic feet of natural gas fuel consumed per mile
Where:
CWFNG = the carbon weight fraction of the natural gas
fuel as calculated in paragraph (f)(3) of this section.
WFCO2 = weight fraction carbon dioxide of the natural gas
fuel calculated using the mole fractions and molecular weights of
the natural gas fuel constituents per
[[Page 36340]]
ASTM D 1945 (incorporated by reference in Sec. 600.011).
(2) [Reserved]
(l)
(1) For ethanol-fueled automobiles and automobiles designed to
operate on mixtures of gasoline and ethanol, the fuel economy in miles
per gallon of ethanol is to be calculated using the following equation:
mpg = (CWF x SG x 3781.8)/((CWFexHC x HC) + (0.429 x CO) +
(0.273 x CO2) + (0.375 x CH3OH) + (0.400 x HCHO)
+ (0.521 x C2H5OH) + (0.545 x
C2H4O))
Where:
CWF = Carbon weight fraction of the fuel as determined in paragraph
(f)(4) of this section and rounded according to paragraph (f)(3) of
this section.
SG = Specific gravity of the fuel as determined in paragraph (f)(4)
of this section and rounded according to paragraph (f)(3) of this
section.
CWFexHC = Carbon weight fraction of exhaust hydrocarbons
= CWF as determined in paragraph (f)(4) of this section and rounded
according to paragraph (f)(3) of this section.
HC = Grams/mile HC as obtained in paragraph (g)(1) of this section.
CO = Grams/mile CO as obtained in paragraph (g)(1) of this section.
CO2 = Grams/mile CO2 as obtained in paragraph
(g)(1) of this section.
CH3OH = Grams/mile CH3OH (methanol) as
obtained in paragraph (g)(1) of this section.
HCHO = Grams/mile HCHO (formaldehyde) as obtained in paragraph
(g)(1) of this section.
C2H5OH = Grams/mile
C2H5OH (ethanol) as obtained in paragraph
(g)(1) of this section.
C2H4O = Grams/mile C2H4O
(acetaldehyde) as obtained in paragraph (g)(1) of this section.
(2) [Reserved]
(m)
(1) For automobiles fueled with liquefied petroleum gas and
automobiles designed to operate on gasoline and liquefied petroleum
gas, the fuel economy in miles per gallon of liquefied petroleum gas is
to be calculated using the following equation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.006
Where:
mpge = miles per gasoline gallon equivalent of liquefied
petroleum gas.
CWFfuel = carbon weight fraction based on the hydrocarbon
constituents in the liquefied petroleum gas fuel as obtained in
paragraph (f)(5) of this section and rounded according to paragraph
(g)(3) of this section.
SG = Specific gravity of the fuel as determined in paragraph (f)(5)
of this section and rounded according to paragraph (g)(3) of this
section.
3781.8 = Grams of H2O per gallon conversion factor.
CWFHC = Carbon weight fraction of exhaust hydrocarbon =
CWFfuel as determined in paragraph (f)(4) of this section
and rounded according to paragraph (f)(3) of this section.
HC = Grams/mile HC as obtained in paragraph (g)(2) of this section.
CO = Grams/mile CO as obtained in paragraph (g)(2) of this section.
CO2 = Grams/mile CO2 as obtained in paragraph
(g)(2) of this section.
(2) [Reserved]
(n) Manufacturers may use a value of 0 grams CO2 per
mile to represent the emissions of electric vehicles and the electric
operation of plug-in hybrid electric vehicles derived from electricity
generated from sources that are not onboard the vehicle.
(o)
(1) For testing with E10, calculate fuel economy using the
following equation, rounded to the nearest 0.1 miles per gallon:
[GRAPHIC] [TIFF OMITTED] TP01AU25.007
Where:
CMFtestfuel = carbon mass fraction of the test fuel,
expressed to three decimal places.
SGtestfuel = the specific gravity of the test fuel as
obtained in paragraph (f)(1) of this section, expressed to three
decimal places.
rH2O = the density of pure water at 60 [deg]F. Use
rH2O = 3781.69 g/gal.
SGbasefuel = the specific gravity of the 1975 base fuel.
Use SGbasefuel = 0.7394.
NHCbasefuel = net heat of combustion of the 1975 base
fuel. Use NHCbasefuel = 43.047 MJ/kg.
NMOG = NMOG emission rate over the test interval or duty cycle in
grams/mile.
CH4 = CH4 emission rate over the test interval or duty
cycle in grams/mile.
CO = CO emission rate over the test interval or duty cycle in grams/
mile.
CO2 = measured tailpipe CO2 emission rate over the test
interval or duty cycle in grams/mile.
Ra = sensitivity factor that represents the response of a
typical vehicle's fuel economy to changes in fuel properties, such
as volumetric energy content. Use Ra = 0.81.
NHCtestfuel = net heat of combustion by mass of test fuel
as obtained in paragraph (f)(1) of this section, expressed to three
decimal places.
(2) [Reserved]
(p) Equations for fuels other than those specified in this section
may be used with advance EPA approval. Alternate calculation methods
for fuel economy may be used in lieu of the methods described in this
section if shown to yield equivalent or superior results and if
approved in advance by the Administrator.
0
56. Amend Sec. 600.114-12 by revising the section heading and
introductory text to read as follows:
Sec. 600.114-12 Vehicle-specific 5-cycle fuel economy CO2 emission
calculations.
Paragraphs (a) through (f) of this section apply to data used for
fuel economy labeling under subpart D of this part. Paragraphs (d)
through (f) of this section are used to calculate 5-cycle carbon-
related exhaust emission values for the purpose of determining optional
credits for CO2-reducing technologies under Sec. 86.1869-12
of this chapter and to calculate 5-cycle CO2 values for the
purpose of fuel economy labeling under subpart D of this part.
* * * * *
0
57. Amend Sec. 600.116-12 by revising paragraphs (a)(11)(iii)(E),
(c)(1) introductory text, and (c)(6)(iii) to read as follows:
[[Page 36341]]
Sec. 600.116-12 Special procedures related to electric vehicles and
hybrid electric vehicles.
(a) * * *
(11) * * *
(iii) * * *
(E) A description of each test group and vehicle configuration that
will use the 5-cycle adjustment factor, including the battery capacity
of the vehicle used to generate the 5-cycle adjustment factor and the
battery capacity of all the vehicle configurations to which it will be
applied.
* * * * *
(c) Determine performance values for hybrid electric vehicles that
have plug-in capability as specified in Sec. Sec. 600.210 and 600.311
using the procedures of SAE J1711 (incorporated by reference in Sec.
600.011), with the following clarifications and modifications:
(1) Calculate fuel economy values representing combined operation
during charge-depleting and charge-sustaining operation using the
following utility factors, except as otherwise specified in this
paragraph (c):
* * * * *
(6) * * *
(iii) For charge-sustaining tests, we may approve alternate Net
Energy Change/Fuel Ratio tolerances as specified in Appendix C of SAE
J1711 to correct final fuel economy values and CO2
emissions. For charge-sustaining tests, do not use alternate Net Energy
Change/Fuel Ratio tolerances to correct emissions of criteria
pollutants. Additionally, if we approve an alternate End-of-Test
criterion or Net Energy Change/Fuel Ratio tolerances for a specific
vehicle, we may use the alternate criterion or tolerances for any
testing we conduct on that vehicle.
* * * * *
0
58. Amend Sec. 600.117 by removing and reserving paragraph (a)(5) and
revising paragraphs (a)(6) and (b) to read as follows:
Sec. 600.117 Interim provisions.
(a) * * *
(6) Manufacturers may alternatively determine fuel economy values
using E10 gasoline test fuel as specified in 40 CFR 1065.710(b).
Calculate fuel economy using the equation specified in Sec. 600.113-
12(o)(1) based on measured CO2 results without adjusting to
account for fuel effects.
* * * * *
(b) For model years 2027 through 2029, manufacturers may determine
fuel economy values using data with E0 test fuel from testing for
earlier model years, subject to the carryover provisions of 40 CFR
86.1839 and Sec. 600.006. Calculate fuel economy using the equation
specified in Sec. 600.113-12(h)(1) based on measured CO2
results without adjusting to account for fuel effects.
* * * * *
0
59. Amend Sec. 600.206-12 by revising paragraphs (a) introductory
text, (a)(4) introductory text, (b), and (c) to read as follows:
Sec. 600.206-12 Calculation and use of FTP-based and HFET-based fuel
economy, CO2 emissions, and carbon-related exhaust emission values for
vehicle configurations.
(a) Fuel economy, CO2 emissions, and carbon-related
exhaust emissions values determined for each vehicle under Sec.
600.113-12(a) and (b) and as approved in Sec. 600.008(c), are used to
determine FTP-based city, HFET-based highway, and combined FTP/Highway-
based fuel economy, CO2 emissions, and carbon-related
exhaust emission values for each vehicle configuration for which data
are available. Note that fuel economy for some alternative fuel
vehicles may mean miles per gasoline gallon equivalent and/or miles per
unit of fuel consumed. For example, electric vehicles will determine
miles per kilowatt-hour in addition to miles per gasoline gallon
equivalent, and fuel cell vehicles will determine miles per kilogram of
hydrogen.
* * * * *
(4) For alcohol dual fuel automobiles and natural gas dual fuel
automobiles the procedures of paragraphs (a)(1) or (2) of this section,
as applicable, shall be used to calculate two separate sets of FTP-
based city, HFET-based highway, and combined values for fuel economy,
CO2 emissions, and carbon-related exhaust emissions for each
vehicle configuration.
* * * * *
(b) If only one equivalent petroleum-based fuel economy value
exists for an electric vehicle configuration, that value, rounded to
the nearest tenth of a mile per gallon, will comprise the petroleum-
based fuel economy for that vehicle configuration.
(c) If more than one equivalent petroleum-based fuel economy value
exists for an electric vehicle configuration, all values for that
vehicle configuration are harmonically averaged and rounded to the
nearest 0.0001 mile per gallon for that vehicle configuration.
0
60. Amend Sec. 600.207-12 by revising paragraphs (a)(1), (a)(4)
introductory text, (b), and (c) to read as follows:
Sec. 600.207-12 Calculation and use of vehicle-specific 5-cycle-based
fuel economy and CO2 emission values for vehicle configurations.
(a) * * *
(1) If only one set of 5-cycle city and highway fuel economy and
CO2 emission values is accepted for a vehicle configuration,
these values, where fuel economy is rounded to the nearest 0.0001 of a
mile per gallon and the CO2 emission value in grams per mile
is rounded to the nearest tenth of a gram per mile, comprise the city
and highway fuel economy and CO2 emission values for that
vehicle configuration. Note that the appropriate vehicle-specific
CO2 values for fuel economy labels based on 5-cycle testing
with E10 test fuel are adjusted as described in Sec. 600.114-12.
* * * * *
(4) For alcohol dual fuel automobiles and natural gas dual fuel
automobiles, the procedures of paragraphs (a)(1) and (2) of this
section shall be used to calculate two separate sets of 5-cycle city
and highway fuel economy and CO2 emission values for each
vehicle configuration.
* * * * *
(b) If only one equivalent petroleum-based fuel economy value
exists for an electric vehicle configuration, that value, rounded to
the nearest tenth of a mile per gallon, will comprise the petroleum-
based 5-cycle fuel economy for that vehicle configuration.
(c) If more than one equivalent petroleum-based 5-cycle fuel
economy value exists for an electric vehicle configuration, all values
for that vehicle configuration are harmonically averaged and rounded to
the nearest 0.0001 mile per gallon for that vehicle configuration.
0
61. Amend Sec. 600.210-12 by revising paragraph (b) to read as
follows:
Sec. 600.210-12 Calculation of fuel economy and CO2 emission values
for labeling.
* * * * *
(b) Specific labels. Except as specified in paragraphs (d) and (e)
of this section, fuel economy and CO2 emissions for specific
labels may be determined by one of two methods. The first is based on
vehicle-specific vehicle configuration 5-cycle data as determined in
Sec. 600.207. This method is available for all vehicles and is
required for vehicles that do not qualify for the second method as
described in Sec. 600.115 (other than electric vehicles). The second
method, the derived 5-cycle method, determines fuel economy and
CO2 emissions values from the FTP and HFET tests using
equations that are derived from vehicle-specific 5-cycle vehicle
configuration data, as determined in paragraph (b)(2) of this section.
Manufacturers may voluntarily lower fuel economy values and raise
CO2 values if they determine that the label values from
either method are not
[[Page 36342]]
representative of the fuel economy or CO2 emissions for that
model type.
(1) Vehicle-specific 5-cycle labels. The city and highway vehicle
configuration fuel economy determined in Sec. 600.207, rounded to the
nearest mpg, and the city and highway vehicle configuration
CO2 emissions determined in Sec. 600.207, rounded to the
nearest gram per mile, comprise the fuel economy and CO2
emission values for specific fuel economy labels, or, alternatively;
(2) Derived 5-cycle labels. Specific city and highway label values
from derived 5-cycle are determined according to the following method:
(i)(A) Determine the derived five-cycle city fuel economy of the
vehicle configuration using the equation below and coefficients
determined by the Administrator:
[GRAPHIC] [TIFF OMITTED] TP01AU25.008
Where:
City Intercept = Intercept determined by the Administrator based on
historic vehicle-specific 5-cycle city fuel economy data.
City Slope = Slope determined by the Administrator based on historic
vehicle-specific 5-cycle city fuel economy data.
Config FTP FE = the vehicle configuration FTP-based city fuel
economy determined under Sec. 600.206, rounded to the nearest
0.0001 mpg.
(B) Determine the derived five-cycle city CO2 emissions
of the vehicle configuration using the equation below and coefficients
determined by the Administrator:
Derived 5-cycle City CO2 = City Intercept + City Slope
[middot] Config FTP CO2
Where:
City Intercept = Intercept determined by the Administrator based on
historic vehicle-specific 5-cycle city fuel economy data.
City Slope = Slope determined by the Administrator based on historic
vehicle-specific 5-cycle city fuel economy data.
Config FTP CO2 = the vehicle configuration FTP-based city
CO2 emissions determined under Sec. 600.206, rounded to
the nearest 0.1 grams per mile. Note that the appropriate Config FTP
CO2 input values for fuel economy labels based on testing
with E10 test fuel are adjusted as referenced in Sec. 600.206-
12(a)(2)(iii).
(ii)(A) Determine the derived five-cycle highway fuel economy of
the vehicle configuration using the equation below and coefficients
determined by the Administrator:
[GRAPHIC] [TIFF OMITTED] TP01AU25.009
Where:
Highway Intercept = Intercept determined by the Administrator based
on historic vehicle-specific 5-cycle highway fuel economy data.
Highway Slope = Slope determined by the Administrator based on
historic vehicle-specific 5-cycle highway fuel economy data.
Config HFET FE = the vehicle configuration highway fuel economy
determined under Sec. 600.206, rounded to the nearest tenth.
(B) Determine the derived five-cycle highway CO2
emissions of the vehicle configuration using the equation below and
coefficients determined by the Administrator:
Derived 5-cycle city Highway CO2 = Highway Intercept +
Highway Slope [middot] Config HFET CO2
Where:
Highway Intercept = Intercept determined by the Administrator based
on historic vehicle-specific 5-cycle highway fuel economy data.
Highway Slope = Slope determined by the Administrator based on
historic vehicle-specific 5-cycle highway fuel economy data.
Config HFET CO2 = the vehicle configuration highway fuel
economy determined under Sec. 600.206, rounded to the nearest
tenth. Note that the appropriate Config HFET CO2 input
values for fuel economy labels based on testing with E10 test fuel
are adjusted as referenced in Sec. 600.206-12(a)(2)(iii).
(iii) The slopes and intercepts of paragraph (a)(2)(iii) of this
section apply.
(3) Specific alternative fuel economy and CO2 emissions
label values for dual fuel vehicles.
(i) Determine an alternative fuel label value for dual fuel
vehicles, rounded to the nearest whole number, as follows:
(A) Specific city and highway fuel economy label values for dual
fuel alcohol-based and natural gas vehicles when using the alternative
fuel are separately determined by the following calculation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.010
Where:
FEalt = The unrounded FTP-based vehicle configuration
city or HFET-based vehicle configuration highway fuel economy from
the alternative fuel, as determined in Sec. 600.206.
5cycle FEgas = The unrounded vehicle-specific or derived
5-cycle vehicle configuration city or highway fuel economy as
determined in paragraph (b)(1) or (2) of this section.
FEgas = The unrounded FTP-based city or HFET-based
vehicle configuration
[[Page 36343]]
highway fuel economy from gasoline, as determined in Sec. 600.206.
(B) Specific city and highway CO2 emission label values
for dual fuel alcohol-based and natural gas vehicles when using the
alternative fuel are separately determined by the following
calculation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.011
Where:
CO2alt = The unrounded FTP-based vehicle configuration
city or HFET-based vehicle configuration highway CO2
emissions value from the alternative fuel, as determined in Sec.
600.206.
5cycle CO2gas = The unrounded vehicle-specific or derived
5-cycle vehicle configuration city or highway CO2
emissions value as determined in paragraph (b)(1) or (b)(2) of this
section.
CO2gas = The unrounded FTP-based city or HFET-based
vehicle configuration highway CO2 emissions value from
gasoline, as determined in Sec. 600.206.
(ii) Optionally, if complete 5-cycle testing has been performed
using the alternative fuel, the manufacturer may choose to use the
alternative fuel label city or highway fuel economy and CO2
emission values determined in Sec. 600.207-12(a)(4)(ii), rounded to
the nearest whole number.
(4) Specific alternative fuel economy and CO2 emissions
label values for electric vehicles. Determine FTP-based city and HFET-
based highway fuel economy label values for electric vehicles as
described in Sec. 600.116. Determine these values by running the
appropriate repeat test cycles. Convert W-hour/mile results to miles
per kW-hr and miles per gasoline gallon equivalent. CO2
label information is based on tailpipe emissions only, so
CO2 emissions from electric vehicles are assumed to be zero.
(5) Specific alternate fuel economy and CO2 emissions
label values for fuel cell vehicles. Determine FTP-based city and HFET-
based highway fuel economy label values for fuel cell vehicles using
procedures specified by the Administrator. Convert kilograms of
hydrogen/mile results to miles per kilogram of hydrogen and miles per
gasoline gallon equivalent. CO2 label information is based
on tailpipe emissions only, so CO2 emissions from fuel cell
vehicles are assumed to be zero.
* * * * *
0
62. Revise the heading of subpart F as set forth above.
0
63. Amend Sec. 600.507-12 by revising paragraphs (a) introductory
text, (b), and (d) to read as follows:
Sec. 600.507-12 Running change data requirements.
(a) Except as specified in paragraph (d) of this section, the
manufacturer shall submit additional running change fuel economy data
as specified in paragraph (b) of this section for any running change
approved or implemented under Sec. 86.1842 of this chapter, which:
* * * * *
(b)(1) The additional running change fuel economy data requirement
in paragraph (a) of this section will be determined based on the sales
of the vehicle configurations in the created or affected base level(s)
as updated at the time of running change approval.
(2) Within each newly created base level as specified in paragraph
(a)(1) of this section, the manufacturer shall submit data from the
highest projected total model year sales subconfiguration within the
highest projected total model year sales vehicle configuration in the
base level.
(3) Within each base level affected by a running change as
specified in paragraph (a)(2) of this section, fuel economy data shall
be submitted for the vehicle configuration created or affected by the
running change which has the highest total model year projected sales.
The test vehicle shall be of the subconfiguration created by the
running change which has the highest projected total model year sales
within the applicable vehicle configuration.
* * * * *
(d) For those model types created under Sec. 600.208-12(a)(2), the
manufacturer shall submit fuel economy data for each subconfiguration
added by a running change.
0
64. Revise Sec. 600.509-12 to read as follows:
Sec. 600.509-12 Voluntary submission of additional data.
(a) The manufacturer may optionally submit data in addition to the
data required by the Administrator.
(b) Additional fuel economy data may be submitted by the
manufacturer for any vehicle configuration which is to be tested as
required in Sec. 600.507 or for which fuel economy data were
previously submitted under paragraph (c) of this section.
(c) Within a base level, additional fuel economy data may be
submitted by the manufacturer for any vehicle configuration which is
not required to be tested by Sec. 600.507.
0
65. Amend Sec. 600.510-12 by:
0
a. Revising the section heading;
0
b. Removing and reserving paragraph (a)(2);
0
c. Revising paragraphs (b) and (g)(1) introductory text; and
0
d. Removing paragraphs (i), (j), and (k).
The revisions read as follows:
Sec. 600.510-12 Calculation of average fuel economy.
* * * * *
(b) For the purpose of calculating average fuel economy under
paragraph (c) of this section:
(1) All fuel economy data submitted in accordance with Sec.
600.006(e) or Sec. 600.512(c) shall be used.
(2) The combined city/highway fuel economy values will be
calculated for each model type in accordance with Sec. 600.208 except
that:
(i) Separate fuel economy values will be calculated for model types
and base levels associated with car lines for each category of
passenger automobiles and light trucks as determined by the Secretary
of Transportation pursuant to paragraph (a)(1) of this section.
(ii) Total model year production data, as required by this subpart,
will be used instead of sales projections;
(iii) [Reserved]
(iv) The fuel economy value will be rounded to the nearest 0.1 mpg;
and
(v) [Reserved]
(vi) At the manufacturer's option, those vehicle configurations
that are self-compensating to altitude changes may be separated by
sales into high-altitude sales categories and low-altitude sales
categories. These separate sales categories may then be treated (only
for the purpose of this section) as separate vehicle configurations in
accordance with the procedure of Sec. 600.208-12(a)(4)(ii).
(3) The fuel economy values for each vehicle configuration are the
combined fuel economy calculated according to Sec. 600.206-12(a)(3)
except that:
(i) Separate fuel economy values will be calculated for vehicle
configurations
[[Page 36344]]
associated with car lines for each category of passenger automobiles
and light trucks as determined by the Secretary of Transportation
pursuant to paragraph (a)(1) of this section; and
(ii) Total model year production data, as required by this subpart
will be used instead of sales projections.
* * * * *
(g)(1) Dual fuel automobiles must provide equal or greater energy
efficiency while operating on the alternative fuel as while operating
on gasoline or diesel fuel to obtain the CAFE credit determined in
paragraphs (c)(2)(iv) and (v) of this section. The following equation
must hold true:
* * * * *
0
66. Amend Sec. 600.512-12 by:
0
a. Revising paragraph (a) introductory text;
0
b. Removing and reserving paragraph (a)(2), (c)(1)(ii), and (c)(2)(ii);
0
c. Revising paragraphs (c)(3);
0
d. Removing and reserving paragraphs (c)(4)(ii), and (c)(5)(ii); and
0
e. Removing paragraph (c)(11).
The revisions read as follows:
Sec. 600.512-12 Model year report.
(a) For each model year, the manufacturer shall submit to the
Administrator a report, known as the model year report, containing all
information necessary for the calculation of the manufacturer's average
fuel economy.
(c) * * *
(3)(i) For manufacturers calculating air conditioning efficiency
credits in support of fuel consumption improvement values under Sec.
600.510(c), a description of the air conditioning system and the total
credits earned for each averaging set, model year, and region, as
applicable.
(ii) Any additional fuel economy data submitted by the manufacturer
under Sec. 600.509;
* * * * *
Sec. 600.514-12 [Removed]
0
67. Remove Sec. 600.514-12.
PART 1036--CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVY-DUTY
HIGHWAY ENGINES
0
68. The authority citation for part 1036 continues to read as follows:
Authority: 42 U.S.C. 7401--7671q.
0
69. Amend Sec. 1036.1 by revising paragraph (a) introductory text to
read as follows:
Sec. 1036.1 Applicability.
(a) Except as specified in Sec. 1036.5, the provisions of this
part apply for engines that will be installed in heavy-duty vehicles
(including glider vehicles). Heavy-duty engines produced before
December 20, 2026 are subject to exhaust emission standards for
NOX, HC, PM, and CO, and related provisions under 40 CFR
part 86, subpart A and subpart N, instead of this part, except as
follows:
* * * * *
0
70. Amend Sec. 1036.5 by revising paragraph (a) and removing paragraph
(e). The revision reads as follows:
Sec. 1036.5 Excluded engines.
(a) The provisions of this part do not apply to engines used in
medium-duty passenger vehicles or other heavy-duty vehicles that are
subject to regulation under 40 CFR part 86, subpart S, except as
specified in 40 CFR part 86, subpart S. For example, this exclusion may
apply for engines used in incomplete vehicles or high-GCWR vehicles as
specified in 40 CFR 86.1801-12.
* * * * *
0
71. Amend Sec. 1036.15 by revising paragraph (b) to read as follows:
Sec. 1036.15 Other applicable regulations.
* * * * *
(b) Part 1037 of this chapter describes emission standards and
other requirements for heavy-duty vehicles, whether or not they use
engines certified under this part.
* * * * *
0
72. Amend Sec. 1036.101 by revising paragraph (a) to read as follows:
Sec. 1036.101 Overview of exhaust emission standards.
(a) You must show that engines meet the criteria pollutant
standards for NOX, HC, PM, and CO as described in Sec.
1036.104. These pollutants are sometimes described collectively as
``criteria pollutants'' because they are either criteria pollutants
under the Clean Air Act or precursors to the criteria pollutants ozone
and PM.
* * * * *
Sec. 1036.108 [Removed]
0
73. Remove Sec. 1036.108.
Sec. 1036.115 [Amended]
0
74. Amend Sec. 1036.115 by removing and reserving paragraph (b).
0
75. Amend Sec. 1036.130 by revising paragraph (b)(5) and removing and
reserving paragraph (c). The revision reads as follows:
Sec. 1036.130 Installation instructions for vehicle manufacturers.
* * * * *
(b) * * *
(5) Describe how your certification is limited for any type of
application. For example, if you certify engines only for use in
emergency vehicles, you must make clear that the engine may only be
installed in emergency vehicles.
* * * * *
0
76. Amend Sec. 1036.135 by revising paragraphs (c)(9) and (e) to read
as follows:
Sec. 1036.135 Labeling.
* * * * *
(c) * * *
(9) Identify any limitations on your certification. For example, if
you certify engines with one or more approved AECDs for emergency
vehicle applications under Sec. 1036.115(h)(4), include the statement:
``THIS ENGINE IS FOR INSTALLATION IN EMERGENCY VEHICLES ONLY''.
* * * * *
(e) You may ask us to approve modified labeling requirements in
this part if you show that it is necessary or appropriate. We will
approve your request if your alternate label is consistent with the
requirements of this part.
* * * * *
0
77. Amend Sec. 1036.150 by:
0
a. Removing and reserving paragraphs (b), (d), and (e);
0
b. Revising paragraph (f);
0
c. Removing and reserving paragraphs (g) through (j), (l) through (n),
(p) through (s), and (w); and
0
d. Removing paragraph (aa).
The revision reads as follows:
Sec. 1036.150 Interim provisions.
* * * * *
(f) Testing exemption for hydrogen engines. Tailpipe HC, and CO
emissions from engines fueled with neat hydrogen are deemed to comply
with the applicable standard. Testing for HC or CO is optional under
this part for these engines.
* * * * *
0
78. Amend Sec. 1036.205 by revising paragraphs (b) introductory text,
(l), (m), (o)(2), and (t) and removing paragraph (aa). The revisions
read as follows:
Sec. 1036.205 Requirements for an application for certification.
* * * * *
(b) Explain how the emission control system operates. Describe in
detail all system components for controlling criteria pollutant
emissions, including all auxiliary emission control devices (AECDs) and
all fuel-system components you will install on any production or test
engine. Identify the part number of each component you describe. For
this paragraph (b), treat as separate AECDs any devices that
[[Page 36345]]
modulate or activate differently from each other. Include all the
following:
* * * * *
(l) Identify the duty-cycle emission standards from Sec.
1036.104(a) and (b) that apply for the engine family. Also identify the
NOX FEL over the FTP for the engine family.
(m) Identify the engine family's deterioration factors and describe
how you developed them (see Sec. 1036.240). Present any test data you
used for this. For engines designed to discharge crankcase emissions to
the ambient atmosphere, use the deterioration factors for crankcase
emission to determine deteriorated crankcase emission levels of
NOX, HC, PM, and CO as specified in Sec. 1036.240(e).
* * * * *
(o) * * *
(2) Identify the value of eCO2FTP from Sec.
1036.235(b).
* * * * *
(t) State whether your certification is limited for certain
engines. For example, you might certify engines only for use in
emergency vehicles or in vehicles with hybrid powertrains. If this is
the case, describe how you will prevent use of these engines in
vehicles for which they are not certified.
* * * * *
0
79. Amend Sec. 1036.225 by removing paragraph (a)(3) and revising
paragraph (f). The revision reads as follows:
Sec. 1036.225 Amending applications for certification.
* * * * *
(f) You may ask us to approve a change to your FEL in certain cases
after the start of production, but before the end of the model year.
The changed FEL may not apply to engines you have already introduced
into U.S. commerce, except as described in this paragraph (f). You may
ask us to approve a change to your FEL in the following cases:
(1) You may ask to raise your FEL for your engine family at any
time. In your request, you must show that you will still be able to
meet the emission standards as specified in subparts B and H of this
part. Use the appropriate FELs with corresponding production volumes to
calculate emission credits for the model year, as described in subpart
H of this part.
(2) You may ask to lower the FEL for your engine family only if you
have test data from production engines showing that emissions are below
the proposed lower FEL. The lower FEL applies only to engines you
produce after we approve the new FEL. Use the appropriate FEL with
corresponding production volumes to calculate emission credits for the
model year, as described in subpart H of this part.
* * * * *
Sec. 1036.230 [Amended]
0
80. Amend Sec. 1036.230 by removing paragraph (f).
0
81. Add Sec. 1036.231 to subpart C to read as follows:
Sec. 1036.231 Powertrain families.
(a) If you choose to perform powertrain testing as specified in
Sec. 1036.545, use good engineering judgment to divide your product
line into powertrain families that are expected to have similar
criteria emissions throughout the useful life as described in this
section. Your powertrain family is limited to a single model year.
(b) Except as specified in paragraph (c) of this section, group
powertrains in the same powertrain family if they share all the
following attributes:
(1) Have the same engine design aspects as specified in Sec.
1036.230.
(2) [Reserved]
(3) Number of clutches.
(4) Type of clutch (e.g., wet or dry).
(5) Presence and location of a fluid coupling such as a torque
converter.
(6) Gear configuration, as follows:
(i) Planetary (e.g., simple, compound, meshed-planet, stepped-
planet, multi-stage).
(ii) Countershaft (e.g., single, double, triple).
(iii) Continuously variable (e.g., pulley, magnetic, toroidal).
(7) Number of available forward gears, and transmission gear ratio
for each available forward gear, if applicable. Count forward gears as
being available only if the vehicle has the hardware and software to
allow operation in those gears.
(8) Transmission oil sump configuration (e.g., conventional or
dry).
(9) The power transfer configuration of any hybrid technology
(e.g., series or parallel).
(10) The type of any RESS (e.g., hydraulic accumulator, Lithium-ion
battery pack, ultracapacitor bank).
(c) For powertrains that share all the attributes described in
paragraph (b) of this section, divide them further into separate
powertrain families based on common calibration attributes. Group
powertrains in the same powertrain family to the extent that powertrain
test results and corresponding emission levels are expected to be
similar throughout the useful life.
(d) You may subdivide a group of powertrains with shared attributes
under paragraph (b) of this section into different powertrain families.
(e) In unusual circumstances, you may group powertrains into the
same powertrain family even if they do not have shared attributes under
in paragraph (b) of this section if you show that their emission
characteristics throughout the useful life will be similar.
(f) If you include the axle when performing powertrain testing for
the family, you must limit the family to include only those axles
represented by the test results. You may include multiple axle ratios
in the family if you test with the axle expected to produce the highest
emission results.
0
82. Amend Sec. 1036.235 by revising the introductory text and
paragraphs (a) and (b) and removing and reserving paragraph (c)(5). The
revisions read as follows:
Sec. 1036.235 Testing requirements for certification.
This section describes the emission testing you must perform to
show compliance with the emission standards in Sec. 1036.104.
(a) Select and configure one or two emission-data engines from each
engine family.
(1) For criteria pollutant emission testing, select the engine
configuration with the highest volume of fuel injected per cylinder per
combustion cycle at the point of maximum torque--unless good
engineering judgment indicates that a different engine configuration is
more likely to exceed (or have emissions nearer to) an applicable
emission standard or FEL. If two or more engines have the same fueling
rate at maximum torque, select the one with the highest fueling rate at
rated speed. In making this selection, consider all factors expected to
affect emission-control performance and compliance with the standards,
including emission levels of all exhaust constituents, especially
NOX and PM. To the extent we allow it for establishing
deterioration factors, select for testing those engine components or
subsystems whose deterioration best represents the deterioration of in-
use engines.
(2) In the case of powertrain testing under Sec. 1036.545, select
a test engine, test hybrid components, test axle and test transmission
as applicable, by considering the whole range of vehicle models covered
by the powertrain family. If the powertrain has more than one
transmission calibration, for example economy vs. performance, you may
weight the results from the powertrain testing in Sec. 1036.545 by the
percentage of vehicles in the family by prior model year for each
configuration. This can be done, for example, through
[[Page 36346]]
the use of survey data or based on the previous model year's sales
volume. Weight the results of Mfuel[cycle],
fnpowertrain/vpowertrain, and W[cycle]
from table 5 to paragraph (o)(8)(i) of Sec. 1036.545 according to the
percentage of vehicles in the family that use each transmission
calibration.
(b) Test your emission-data engines using the procedures and
equipment specified in subpart F of this part. In the case of dual-fuel
and flexible-fuel engines, measure emissions when operating with each
type of fuel for which you intend to certify the engine. For criteria
pollutant emission testing, measure NOX, PM, CO, and NMHC
emissions using each duty cycle specified in Sec. 1036.104. Determine
brake-specific CO2 emissions over the FTP,
eCO2FTP, as a reference value for calculating emission rates
from in-use engines under Sec. 1036.530, as applicable. You may
alternatively determine eCO2FTP, based on brake-specific
CO2 emissions over the SET, with our advance approval, if
you demonstrate that engines from the engine family will be used only
with tractors.
* * * * *
Sec. 1036.241 [Removed]
0
83. Remove Sec. 1036.241.
0
84. Amend Sec. 1036.245 by revising paragraph (c)(3) to read as
follows:
Sec. 1036.245 Deterioration factors for exhaust emission standards.
* * * * *
(c) * * *
(3) Perform service accumulation in the laboratory by operating the
engine or hybrid powertrain repeatedly over one of the following test
sequence, or a different test sequence that we approve in advance:
(i) Operate at idle for 2 hours.
(ii) Operate for 105 1 hours over a repeat sequence of
one FTP followed by one RMC.
(iii) Operate over one LLC.
(iv) Operate at idle for 2 hours.
(v) Shut down the engine for cooldown to ambient temperature.
* * * * *
0
85. Revise Sec. 1036.301 to read as follows:
Sec. 1036.301 Selective enforcement audits.
Selective enforcement audits apply for engines and powertrains as
specified in 40 CFR part 1068, subpart E.
0
86. Amend Sec. 1036.415 by revising paragraph (g) to read as follows:
Sec. 1036.415 Preparing and testing engines.
* * * * *
(g) For stop-start and automatic engine shutdown systems, override
idle-reduction features if they are adjustable. If those systems are
not adjustable,, set the 1-Hz emission rate to zero for all regulated
pollutants when the idle-reduction feature is active. Do not exclude
these data points under Sec. 1036.530(c)(3)(ii). Note that systems are
considered ``adjustable'' if vehicle owners, dealers, or other service
outlets can override the idle-reduction features.
0
87. Amend Sec. 1036.501 by revising paragraphs (a), (d), and (h) to
read as follows:
Sec. 1036.501 General testing provisions.
(a) Use the equipment and procedures specified in this subpart and
40 CFR part 1065 to determine whether engines meet the emission
standards in Sec. 1036.104.
* * * * *
(d) If your engine is intended for installation in a vehicle
equipped with nonadjustable stop-start technology as described in Sec.
1036.415(g), you may shut the engine down during idle portions of the
duty cycle to represent in-use operation. We recommend installing a
production engine starter motor and letting the engine's ECM manipulate
the starter motor to control the engine stop and start events. Use good
engineering judgment to address the effects of dynamometer inertia on
restarting the engine by, for example, using a larger starter motor or
declutching the engine from the dynamometer during restart.
* * * * *
(h) For testing engines that use regenerative braking through the
crankshaft only to power an electric heater for aftertreatment devices,
you may use the nonhybrid engine testing procedures in Sec. Sec.
1036.510, 1036.512, and 1036.514 only if the recovered energy is less
than 10 percent of the total positive work for each applicable test
interval. Otherwise, use powertrain testing procedures specified for
hybrid powertrains to measure emissions. For engines that power an
electric heater with a battery, you must meet the requirements related
to charge-sustaining operation as described in 40 CFR 1066.501(a)(3).
Sec. 1036.505 [Removed]
0
88. Remove Sec. 1036.505.
0
89. Amend Sec. 1036.510 by:
0
a. Revising paragraphs (b)(2) introductory text and (b)(2)(vii) and
(viii); and
0
b. Removing and reserving paragraph (e).
The revisions read as follows:
Sec. 1036.510 Supplemental Emission Test.
* * * * *
(b) * * *
(2) Test hybrid powertrains as described in Sec. 1036.545, except
as specified in this paragraph (b)(2). Do not compensate the duty cycle
for the distance driven as described in Sec. 1036.545(g)(4). For
hybrid engines, select the transmission model parameters as described
in Sec. 1036.510(b)(viii), . Disregard duty cycles in Sec.
1036.545(j). For cycles that begin with idle, leave the transmission in
neutral or park for the full initial idle segment. Place the
transmission into drive no earlier than 5 seconds before the first
nonzero vehicle speed setpoint. For SET testing only, place the
transmission into park or neutral when the cycle reaches the final idle
segment. Use the following vehicle parameters instead of those in Sec.
1036.545 to define the vehicle model in Sec. 1036.545(a)(3):
* * * * *
(vii) Select a combination of drive axle ratio, ka, and
a tire radius, r, that represents the worst-case combination of top
gear ratio, drive axle ratio, and tire size for emissions expected for
vehicles in which the hybrid engine or hybrid powertrain will be
installed. This is typically the highest axle ratio and smallest tire
radius. Disregard configurations or settings corresponding to a maximum
vehicle speed below 60 mi/hr in selecting a drive axle ratio and tire
radius, unless you can demonstrate that in-use vehicles will not exceed
that speed. You may request preliminary approval for selected drive
axle ratio and tire radius consistent with the provisions of Sec.
1036.210. If the hybrid engine or hybrid powertrain is used exclusively
in vehicles not capable of reaching 60 mi/hr, you may request that we
approve an alternate test cycle and cycle-validation criteria as
described in 40 CFR 1066.425(b)(5). Note that hybrid engines rely on a
specified transmission that is different for each duty cycle; the
transmission's top gear ratio therefore depends on the duty cycle,
which will in turn change the selection of the drive axle ratio and
tire size. For example, Sec. 1036.520 prescribes a different top gear
ratio than this paragraph (b)(2).
(viii) If you are certifying a hybrid engine, use a default
transmission efficiency of 0.95 and create the vehicle model along with
its default transmission shift strategy as described in Sec.
1036.545(a)(3)(ii). Specify the transmission type as Automatic
Transmission for all engines and for all duty cycles, except that the
transmission type is Automated Manual Transmission for Heavy HDE
operating over the SET duty cycle. For automatic transmissions set
neutral idle to ``Y'' in
[[Page 36347]]
the vehicle file. Select gear ratios for each gear as shown in the
following table:
Table 1 to Paragraph (b)(2)(vii) of Sec. 1036.510--GEM HIL Input for Gear Ratio
----------------------------------------------------------------------------------------------------------------
Spark-ignition HDE, light
Gear number HDE, and medium HDE-- all Heavy HDE-- LLC and FTP Heavy HDE-- SET duty
duty cycles duty cycles cycle
----------------------------------------------------------------------------------------------------------------
1.............................. 3.10 3.51 12.8
2.............................. 1.81 1.91 9.25
3.............................. 1.41 1.43 6.76
4.............................. 1.00 1.00 4.90
5.............................. 0.71 0.74 3.58
6.............................. 0.61 0.64 2.61
7.............................. ............................. ....................... 1.89
8.............................. ............................. ....................... 1.38
9.............................. ............................. ....................... 1.00
10............................. ............................. ....................... 0.73
Lockup Gear.................... 3 3 .......................
----------------------------------------------------------------------------------------------------------------
* * * * *
0
90. Amend Sec. 1036.512 by revising paragraphs (b)(2)(iv) and removing
and reserving paragraph (e). The revision reads as follows:
Sec. 1036.512 Federal Test Procedure.
* * * * *
(b) * * *
(2) * * *
(iv) For plug-in hybrid powertrains, test over the FTP in both
charge-sustaining and charge-depleting operation for criteria pollutant
determination.
* * * * *
0
91. Amend Sec. 1036.514 by revising paragraph (b)(4) to read as
follows:
Sec. 1036.514 Low Load Cycle.
* * * * *
(b) * * *
(4) Adjust procedures in this section as described in Sec.
1036.510(d) and (e) for plug-in hybrid powertrains to determine
criteria pollutant emissions, replacing ``SET'' with ``LLC''. Note that
the LLC is therefore the preconditioning duty cycle for plug-in hybrid
powertrains.
* * * * *
0
92. Amend Sec. 1036.520 by revising paragraph (b)(1) to read as
follows:
Sec. 1036.520 Determining power and vehicle speed values for
powertrain testing.
* * * * *
(b) * * *
(1) Use vehicle parameters, other than power, as specified in Sec.
1036.510(b)(2). Use the applicable automatic transmission as specified
in Sec. 1036.510(b)(2)(vii).
* * * * *
0
93. Amend Sec. 1036.530 by revising paragraphs (e) and (g) to read as
follows:
Sec. 1036.530 Test procedures for off-cycle testing.
* * * * *
(e) Normalized CO2 emission mass over a 300 second test
interval. For engines subject to compression-ignition standards,
determine the normalized CO2 emission mass over each 300
second test interval, mCO2,norm,testinterval, to the nearest
0.01% using the following equation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.012
Eq. 1036.530-2
Where:
mCO2,testinterval = total CO2 emission mass
over the test interval.
eCO2FTP = the engine's brake-specific CO2 over
the FTP duty cycle, as described in Sec. 1036.235(b).
Pmax = the highest value of rated power for all the
configurations included in the engine family.
ttestinterval = duration of the test interval. Note that
the nominal value is 300 seconds.
Example
mCO2,testinterval = 3948 g
eCO2FTP = 428.2 g/hp[middot]hr
Pmax = 406.5 hp
ttestinterval = 300.01 s = 0.08 hr
[GRAPHIC] [TIFF OMITTED] TP01AU25.013
mCO2,norm,testinterval = 0.2722 = 27.22%
* * * * *
(g) Off-cycle emissions quantities. Determine the off-cycle
emissions quantities as follows:
(1) Spark-ignition. For engines subject to spark-ignition
standards, the off-cycle emission quantity,
e[emission],offcycle, is the value for CO2-
specific emission mass for a given pollutant over the test interval
representing the shift-day converted to a brake-specific value, as
calculated for each measured pollutant using the following equation:
[[Page 36348]]
[GRAPHIC] [TIFF OMITTED] TP01AU25.014
Eq. 1036.530-3
Where:
m[emission] = total emission mass for a given pollutant
over the test interval as determined in paragraph (d)(2) of this
section.
mCO2 = total CO2 emission mass over the test
interval as determined in paragraph (d)(2) of this section.
eCO2,FTP = the engine's brake-specific CO2
over the FTP duty cycle.
Example
mNOX = 1.337 g
mCO2 = 18778 g
eCO2,FTP = 505.1 g/hp[middot]hr
[GRAPHIC] [TIFF OMITTED] TP01AU25.015
eNOX, offcycle = 0.035 g/hp[middot]hr = 35 mg/
hp[middot]hr
(2) Compression-ignition. For engines subject to compression-
ignition standards, determine the off-cycle emission quantity for each
bin. When calculating mean bin emissions from ten engines to apply the
pass criteria for engine families in Sec. 1036.425(c), set any
negative off-cycle emissions quantity to zero before calculating mean
bin emissions.
(i) Off-cycle emissions quantity for bin 1. The off-cycle emission
quantity for bin 1, is the mean NOX mass emission rate from
all test intervals associated with bin 1 as calculated using the
following equation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.016
Eq. 1036.530-4
Where:
i = an indexing variable that represents one 300 second test
interval.
N = total number of 300 second test intervals in bin 1.
mNOXtestinterval,i = total NOX emission mass
over the test interval i in bin 1 as determined in paragraph (d)(2)
of this section.
ttestinterval,i = total time of test interval i in bin 1 as
determined in paragraph (d)(1) of this section. Note that the
nominal value is 300 seconds.
Example
N = 10114
mNOx,testinterval,1 = 0.021 g
mNOx,testinterval,2 = 0.025 g
mNOx,testinterval,3 = 0.031 g
ttestinterval,1 = 299.99 s
ttestinterval,2 = 299.98 s
ttestinterval,3 = 300.04 s
[GRAPHIC] [TIFF OMITTED] TP01AU25.017
mi = 0.000285 g/s = 1.026 g/hr
(ii) Off-cycle emissions quantity for bin 2. The off-cycle emission
quantity for bin 2, e[emission],offcycle,bin2, is the value
for CO2-specific emission mass for a given pollutant of all
the 300 second test intervals in bin 2 combined and converted to a
brake-specific value, as calculated for each measured pollutant using
the following equation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.018
Eq. 1036.530-5
Where:
i = an indexing variable that represents one 300 second test
interval.
N = total number of 300 second test intervals in bin 2.
m[emission],testinterval,i = total emission mass for a
given pollutant over the test interval i in bin 2 as determined in
paragraph (d)(2) of this section.
mCO2,testinterval,i = total CO2 emission mass
over the test interval i in bin 2 as determined in paragraph (d)(2)
of this section.
eCO2,FTP = the engine's brake-specific CO2
over the FTP duty cycle.
Example
N = 15439
mNOx1 = 0.546 g
mNOx2 = 0.549 g
mNOx3 = 0.556 g
mCO2,1 = 10950.2 g
mCO2,2 = 10961.3 g
mCO2,3 = 10965.3 g
eCO2,FTP = 428.1 g/hp[middot]hr
[GRAPHIC] [TIFF OMITTED] TP01AU25.019
[[Page 36349]]
eNOx,offcycle,bin2 = 0.026 g/hp[middot]hr = 26 mg/
hp[middot]hr
* * * * *
Sec. Sec. 1036.535, 1036.540, and 1036.543 [Removed]
0
94. Remove Sec. Sec. 1036.535, 1036.540, and 1036.543.
0
95. Revise and republish Sec. 1036.545 to read as follows:
Sec. 1036.545 Powertrain testing.
This section describes the procedure to test a powertrain that
includes an engine coupled with a transmission, drive axle, and hybrid
components or any assembly with one or more of those hardware elements.
The powertrain test procedure is one option for certifying hybrid
powertrains to the engine standards in Sec. 1036.104.
(a) General test provisions. The following provisions apply broadly
for testing under this section:
(1) [Reserved]
(2) The procedures of 40 CFR part 1065 apply for testing in this
section except as specified. This section uses engine parameters and
variables that are consistent with 40 CFR part 1065.
(3) Powertrain testing depends on models to calculate certain
parameters. You can use the detailed equations in this section to
create your own models, or use the GEM HIL model contained within GEM
Phase 2, Version 4.0 (incorporated by reference, see Sec. 1036.810) to
simulate vehicle hardware elements as follows:
(i) Create driveline and vehicle models that calculate the angular
speed setpoint for the test cell dynamometer, fnref,dyno,
based on the torque measurement location. Use the detailed equations in
paragraph (f) of this section, the GEM HIL model's driveline and
vehicle submodels, or a combination of the equations and the submodels.
You may use the GEM HIL model's transmission submodel in paragraph (f)
to simulate a transmission only if testing hybrid engines. For hybrid
engines intended for vehicles with automatic transmissions, update the
driver_in_gear signal within the driver interface block in the GEM HIL
model with the transmission state (in-gear or idle) as a function of
time as defined by the duty cycles in this part.
(ii) Create a driver model or use the GEM HIL model's driver
submodel to simulate a human driver modulating the throttle and brake
pedals to follow the test cycle as closely as possible.
(iii) Create a cycle-interpolation model or use the GEM HIL model's
cycle submodel to interpolate the duty-cycles and feed the driver model
the duty-cycle reference vehicle speed for each point in the duty-
cycle.
(4) The powertrain test procedure in this section is designed to
simulate operation of different vehicle configurations over specific
duty cycles. See paragraph (j) of this section.
(5) [Reserved]
(6) For hybrid powertrains with no plug-in capability, correct for
the net energy change of the energy storage device as described in 40
CFR 1066.501(a)(3). For plug-in hybrid electric powertrains, follow 40
CFR 1066.501(a)(3) to determine End-of-Test for charge-depleting
operation.
(7) through (8) [Reserved]
(9) If you test a powertrain over the Low Load Cycle specified in
Sec. 1036.514, control and apply the electrical accessory loads. We
recommend using a load bank connected directly to the powertrain's
electrical system. You may instead use an alternator with dynamic
electrical load control. Use good engineering judgment to account for
the efficiency of the alternator or the efficiency of the powertrain to
convert the mechanical energy to electrical energy.
(10) The following instruments are required with plug-in hybrid
systems to determine required voltages and currents during testing and
must be installed on the powertrain to measure these values during
testing:
(i) Measure the voltage and current of the battery pack directly
with a DC wideband power analyzer to determine power. Measure all
current entering and leaving the battery pack. Do not measure voltage
upstream of this measurement point. The maximum integration period for
determining amp-hours is 0.05 seconds. The power analyzer must have an
accuracy for measuring current and voltage of 1% of point or 0.3% of
maximum, whichever is greater. The power analyzer must not be
susceptible to offset errors while measuring current.
(ii) If safety considerations do not allow for measuring voltage,
you may determine the voltage directly from the powertrain ECM.
(11) The following figure provides an overview of testing under
this section:
BILLING CODE 6560-50-P
[[Page 36350]]
[GRAPHIC] [TIFF OMITTED] TP01AU25.020
BILLING CODE 6560-50-C
(b) Test configuration. Select a powertrain for testing as
described in Sec. 1036.235. Set up the engine according to 40 CFR
1065.110 and 1065.405(b). Set the engine's idle speed to warm idle
speed defined in 40 CFR 1065.1001.
(1) The default test configuration consists of a powertrain with
all components upstream of the axle. This involves connecting the
powertrain's output shaft directly to the dynamometer or to a gear box
with a fixed gear ratio and measuring torque at the axle input shaft.
You may instead set up the dynamometer to connect at the wheel hubs and
measure torque at that location. The preceding sentence may apply if
your powertrain configuration requires it, such as for hybrid
powertrains or if you want to represent the axle performance with
powertrain test results. You may alternatively test the powertrain with
a chassis dynamometer if you measure speed and torque at the
powertrain's output shaft or wheel hubs.
(2) For testing hybrid engines, connect the engine's crankshaft
directly to the dynamometer and measure torque at that location.
[[Page 36351]]
(c) Powertrain temperatures during testing. Cool the powertrain
during testing so temperatures for oil, coolant, block, head,
transmission, battery, and power electronics are within the
manufacturer's expected ranges for normal operation. You may use
electronic control module outputs to comply with this paragraph (c).
You may use auxiliary coolers and fans.
(d) Powertrain break in. Break in the powertrain as a complete
system using the engine break-in procedure in 40 CFR 1065.405(c), or
take the following steps to break in the engine, axle assembly, and
transmission separately as applicable: (1) Break in the engine
according to 40 CFR 1065.405(c).
(2) Break in the axle assembly using good engineering judgment.
Maintain gear oil temperature at or below 100 [deg]C throughout the
break-in period.
(3) Break in the transmission using good engineering judgment.
Maintain transmission oil temperature at (87 to 93) [deg]C for
automatic transmissions and transmissions having more than two friction
clutches, and at (77 to 83) [deg]C for all other transmissions. You may
ask us to approve a different range of transmission oil temperatures if
you have data showing that it better represents in-use operation.
(e) Dynamometer setup. Set the dynamometer to operate in speed-
control mode (or torque-control mode for hybrid engine testing at idle,
including idle portions of transient duty cycles). Record data as
described in 40 CFR 1065.202. Command and control the dynamometer speed
at a minimum of 5 Hz, or 10 Hz for testing hybrid engines. Run the
vehicle model to calculate the dynamometer setpoints at a rate of at
least 100 Hz. If the dynamometer's command frequency is less than the
vehicle model dynamometer setpoint frequency, subsample the calculated
setpoints for commanding the dynamometer setpoints.
(f) Driveline and vehicle model. Use the GEM HIL model's driveline
and vehicle submodels or the equations in this paragraph (f) to
calculate the dynamometer speed setpoint, fnref,dyno, based
on the torque measurement location. For all powertrains, configure GEM
with the accessory load set to zero. For hybrid engines, configure GEM
with the applicable accessory load as specified in Sec. Sec. 1036.514
and 1036.525. For all powertrains and hybrid engines, configure GEM
with the tire slip model disabled.
(1) Driveline model with a transmission in hardware. For testing
with torque measurement at the axle input shaft or wheel hubs,
calculate, fnref,dyno, using the GEM HIL model's driveline
submodel or the following equation:
[GRAPHIC] [TIFF OMITTED] TP01AU25.024
Eq. 1036.545-1
Where:
ka[speed] = drive axle ratio as determined in paragraph
(h) of this section. Set ka[speed] equal to 1.0 if torque
is measured at the wheel hubs.
vrefi = simulated vehicle reference speed as calculated
in paragraph (f)(3) of this section.
r[speed] = tire radius as determined in paragraph (h) of
this section.
(2) Driveline model with a simulated transmission. For testing with
the torque measurement at the engine's crankshaft,
fnref,dyno is the dynamometer target speed from the GEM HIL
model's transmission submodel. You may request our approval to change
the transmission submodel, as long as the changes do not affect the
gear selection logic. Before testing, initialize the transmission model
with the engine's measured torque curve and the applicable steady-state
fuel map from the GEM HIL model. Configure the torque converter to
simulate neutral idle when using this procedure to perform the
Supplemental Emission Test (SET) testing under Sec. 1036.510. You may
change engine commanded torque at idle to better represent CITT for
transient testing under Sec. 1036.512. You may change the simulated
engine inertia to match the inertia of the engine under test. We will
evaluate your requests under this paragraph (f)(2) based on your
demonstration that the adjusted testing better represents in-use
operation.
(i) The transmission submodel needs the following model inputs:
(A) Torque measured at the engine's crankshaft.
(B) Engine estimated torque determined from the electronic control
module or by converting the instantaneous operator demand to an
instantaneous torque in N[middot]m.
(C) Dynamometer mode when idling (speed-control or torque-control).
(D) Measured engine speed when idling.
(E) Transmission output angular speed, fni,transmission,
calculated as follows:
[GRAPHIC] [TIFF OMITTED] TP01AU25.021
Eq. 1036.545-2
Where:
ka[speed] = drive axle ratio as determined in paragraph
(h) of this section.
vrefi = simulated vehicle reference speed as calculated
in paragraph (f)(3) of this section.
r[speed] = tire radius as determined in paragraph (h) of
this section.
(ii) The transmission submodel generates the following model
outputs:
(A) Dynamometer target speed.
(B) Dynamometer idle load.
(C) Transmission engine load limit.
(D) Engine speed target.
(3) Vehicle model. Calculate the simulated vehicle reference speed,
[nu]refi, using the GEM HIL model's vehicle submodel or the
equations in this paragraph (f)(3):
[GRAPHIC] [TIFF OMITTED] TP01AU25.022
Eq. 1036.545-3
Where:
i = a time-based counter corresponding to each measurement during
the sampling period. Let vref1 = 0; start calculations at
[[Page 36352]]
i = 2. A 10-minute sampling period will generally involve 60,000
measurements.
T = instantaneous measured torque at the axle input, measured at the
wheel hubs, or simulated by the GEM HIL model's transmission
submodel. For configurations with multiple torque measurements, such
as when measuring torque at the wheel hubs, T is the sum of all
torque measurements.
Effaxle = axle efficiency. Use Effaxle = 0.955
for T >= 0, and use Effaxle = 1/0.955 for T < 0. Use
Effaxle = 1.0 if torque is measured at the wheel hubs.
M = vehicle mass for a vehicle class as determined in paragraph (h)
of this section.
g = gravitational constant = 9.80665 m/s\2\.
Crr = coefficient of rolling resistance for a vehicle
class as determined in paragraph (h) of this section.
Gi-1 = the percent grade interpolated at distance,
Di-1, from the duty cycle in Sec. 1036.510 and appendix
B to this part, corresponding to measurement (i-1).
[GRAPHIC] [TIFF OMITTED] TP01AU25.023
Eq. 1036.545-4
r = air density at reference conditions. Use r = 1.1845 kg/m\3\.
CdA = drag area for a vehicle class as determined in
paragraph (h) of this section.
Fbrake,i-1 = instantaneous braking force applied by
the driver model.
Fgrade,i-1 = M [middot] g [middot]
sin(atan(Gi-1))
Eq. 1036.545-5
[Delta]t = the time interval between measurements. For example, at
100 Hz, [Delta]t = 0.0100 seconds.
Mrotating = inertial mass of rotating components. Let
Mrotating = 340 kg for Light HDE or Medium HDE, and 1,021
kg for Heavy HDE.
(g) Driver model. Use the GEM HIL model's driver submodel or design
a driver model to simulate a human driver modulating the throttle and
brake pedals. In either case, tune the model to follow the test cycle
as closely as possible meeting the following specifications:
(1) The driver model must meet the following speed requirements:
(i) [Reserved]
(ii) For operation over the SET as defined Sec. 1036.510, the
Federal Test Procedure (FTP) as defined in Sec. 1036.512, and the Low
Load Cycle (LLC) as defined in Sec. 1036.514, the speed requirements
described in 40 CFR 1066.425(b) and (c).
(iii) The exceptions in 40 CFR 1066.425(b)(4) apply to the SET,
FTP, and LLC.
(iv) If the speeds do not conform to these criteria, the test is
not valid and must be repeated.
(2) Send a brake signal when operator demand is zero and vehicle
speed is greater than the reference vehicle speed from the test cycle.
Include a delay before changing the brake signal to prevent dithering,
consistent with good engineering judgment.
(3) Allow braking only if operator demand is zero.
(h)-(i) [Reserved]
(j) Duty cycles to evaluate. Operate the powertrain over each of
the duty cycles specified in Sec. Sec. 1036.510, 1036.512, and
1036.514 as applicable.
(k)-(l) [Reserved]
(m) Measured output speed validation. For each test point, validate
the measured output speed with the corresponding reference values. If
speed is measured at more than one location, the measurements at each
location must meet validation requirements. If the range of reference
speed is less than 10 percent of the mean reference speed, you need to
meet only the standard error of the estimate in table 4 to this
paragraph (m). You may delete points when the vehicle is stopped. If
your speed measurement is not at the location of fnref,
correct your measured speed using the constant speed ratio between the
two locations. Apply cycle-validation criteria for each separate
transient or highway cruise cycle based on the following parameters:
Table 4 to Paragraph (m) of Sec. 1036.545--Cycle-Validation Criteria
------------------------------------------------------------------------
Parameter \a\ Speed control
------------------------------------------------------------------------
Slope, a1.............................. 0.990 <= a1 <= 1.010.
Absolute value of intercept, <= 2.0% of maximum fnref speed.
[verbar]a0[verbar].
Standard error of the estimate, SEE.... <= 2.0% of maximum fnref speed.
Coefficient of determination, r \2\.... >= 0.990.
------------------------------------------------------------------------
\a\ Determine values for specified parameters as described in 40 CFR
1065.514(e) by comparing measured and reference values for fnref,dyno.
Sec. 1036.550 [Removed]
0
96. Remove Sec. 1036.550.
0
97. Amend Sec. 1036.580 by revising the introductory text and
paragraph (c) to read as follows:
Sec. 1036.580 Infrequently regenerating aftertreatment devices.
For engines using aftertreatment technology with infrequent
regeneration events that may occur during testing, take one of the
following approaches to account for the emission impact of regeneration
on criteria pollutant emissions:
* * * * *
(c) You may choose to make no adjustments to measured emission
results if you determine that regeneration does not significantly
affect emission levels for an engine family (or configuration) or if it
is not practical to identify when regeneration occurs. You may omit
adjustment factors under this paragraph (c) individual pollutants under
this paragraph (c) as appropriate. If you choose not to make
adjustments under paragraph (a) or (b) of this section, your engines
must meet emission standards for all testing, without regard to
regeneration.
* * * * *
0
98. Amend Sec. 1036.605 by revising paragraphs (b) and (g) to read as
follows:
Sec. 1036.605 Alternate emission standards for engines used in
specialty vehicles.
* * * * *
(b) Compression-ignition engines must be of a configuration that is
identical to one that is certified under 40 CFR part 1039, and must be
certified with a family emission limit for PM of 0.020 g/kW-hr using
the same duty cycles that apply under 40 CFR part 1039.
* * * * *
(g) Engines certified under this section may not generate or use
emission credits under this part or under 40 CFR part 1039.
Sec. Sec. 1036.610, 1036.615, 1036.620, 1036.625, 1036.630, and
1036.635 [Removed]
0
99. Remove Sec. Sec. 1036.610, 1036.615, 1036.620, 1036.625, 1036.630,
1036.635.
0
100. Revise and republish Sec. 1036.701 to read as follows:
Sec. 1036.701 General provisions.
(a) You may average, bank, and trade (ABT) emission credits for
purposes of certification as described in this subpart and in subpart B
of this part to show compliance with the standards of Sec. Sec.
1036.104. Participation in this
[[Page 36353]]
program is voluntary. Note that certification to NOX
standards in Sec. 1036.104 is based on a family emission limit (FEL).
(b) The definitions of subpart I of this part apply to this subpart
in addition to the following definitions:
(1) Actual emission credits means emission credits you have
generated that we have verified by reviewing your final report.
(2) Averaging set means a set of engines in which emission credits
may be exchanged. See Sec. 1036.740.
(3) Broker means any entity that facilitates a trade of emission
credits between a buyer and seller.
(4) Buyer means the entity that receives emission credits as a
result of a trade.
(5) Reserved emission credits means emission credits you have
generated that we have not yet verified by reviewing your final report.
(6) Seller means the entity that provides emission credits during a
trade.
(7) Standard means the emission standard that applies under subpart
B of this part for engines not participating in the ABT program of this
subpart.
(8) Trade means to exchange emission credits, either as a buyer or
seller.
(c) Emission credits may be exchanged only within an averaging set,
except as specified in Sec. 1036.740.
(d) You may not use emission credits generated under this subpart
to offset any emissions that exceed an FEL or standard. This paragraph
(d) applies for all testing, including certification testing, in-use
testing, selective enforcement audits, and other production-line
testing. However, if emissions from an engine exceed an FEL or standard
(for example, during a selective enforcement audit), you may use
emission credits to recertify the engine family with a higher FEL that
applies only to future production.
(e) You may use either of the following approaches to retire or
forego emission credits:
(1) You may retire emission credits generated from any number of
your engines. This may be considered donating emission credits to the
environment. Identify any such credits in the reports described in
Sec. 1036.730. Engines must comply with the applicable FELs even if
you donate or sell the corresponding emission credits. Donated credits
may no longer be used by anyone to demonstrate compliance with any EPA
emission standards.
(2) You may certify an engine family using an FEL below the
emission standard as described in this part and choose not to generate
emission credits for that family. If you do this, you do not need to
calculate emission credits for those engine families, and you do not
need to submit or keep the associated records described in this subpart
for that family.
(f) Emission credits may be used in the model year they are
generated. Surplus emission credits may be banked for future model
years.
(g) You may increase or decrease an FEL during the model year by
amending your application for certification under Sec. 1036.225. The
new FEL may apply only to engines you have not already introduced into
commerce.
(h)-(j) [Reserved]
(k) Engine families you certify with a nonconformance penalty under
40 CFR part 86, subpart L, may not generate emission credits.
0
101. Revise and republish Sec. 1036.705 to read as follows:
Sec. 1036.705 Generating and calculating emission credits.
(a) The provisions of this section apply separately for calculating
NOX emission credits.
(b) For each participating family, calculate positive or negative
emission credits relative to the otherwise applicable emission
standard. Calculate positive emission credits for a family that has an
FEL below the standard. Calculate negative emission credits for a
family that has an FEL above the standard. Sum your positive and
negative credits for the model year before rounding. Calculate emission
credits to the nearest megagram (Mg) for each family using the
following equation:
Emission credits (Mg) = (Std-FL) [middot] CF [middot] Volume [middot]
UL [middot] c
Eq. 1036.705-1
Where:
Std = the emission standard, in (mg NOX)/hp[middot]hr
that applies under subpart B of this part for engines not
participating in the ABT program of this subpart (the ``otherwise
applicable standard'').
FL = the engine family's FEL, in mg/hp[middot]hr, rounded to the
same number of decimal places as the emission standard.
CF = a transient cycle conversion factor (hp[middot]hr/mile),
calculated by dividing the total (integrated) horsepower-hour over
the applicable duty cycle by 6.3 miles for engines subject to spark-
ignition standards and 6.5 miles for engines subject to compression-
ignition standards. This represents the average work performed over
the duty cycle.
Volume = the number of engines eligible to participate in the
averaging, banking, and trading program within the given engine
family during the model year, as described in paragraph (c) of this
section.
UL = the useful life for the standard that applies for a given
primary intended service class, in miles.
c = 10-9.
Example for Model Year 2028 Heavy HDE Generating NOX credits
Std = 35 mg/hp[middot]hr
FEL = 20 mg/hp[middot]hr
CF = 9.78 hp[middot]hr/mile
Volume = 15,342
UL = 650,000 miles
c = 10-6
Emission credits = (35-20) [middot] 9.78 [middot] 15,342 [middot]
650,000 [middot] 10-9
Emission credits = 1,463 Mg
(c) Compliance with the requirements of this subpart is determined
at the end of the model year by calculating emission credits based on
actual production volumes, excluding the following engines:
(1) Engines that you do not certify to the standards of this part
because they are permanently exempted under subpart G of this part or
under 40 CFR part 1068.
(2) Exported engines.
(3) Engines not subject to the requirements of this part, such as
those excluded under Sec. 1036.5.
(4) Engines certified to state emission standards that are
different than the emission standards referenced in this section, and
intended for sale in a state that has adopted those emission standards.
(5) Any other engines if we indicate elsewhere in this part that
they are not to be included in the calculations of this subpart.
0
102. Revise Sec. 1036.710 to read as follows:
Sec. 1036.710 Averaging.
(a) Averaging is the exchange of emission credits among your engine
families. You may average emission credits only within the same
averaging set, except as specified in Sec. 1036.740.
(b) You may certify one or more engine families to an FEL above the
applicable standard, subject to any applicable FEL caps and other the
provisions in subpart B of this part, if you show in your application
for certification that your projected balance of all emission-credit
transactions in that model year is greater than or equal to zero.
(c) If you certify an engine family to an FEL that exceeds the
otherwise applicable standard, you must obtain enough emission credits
to offset the engine family's deficit by the due date for the final
report required in Sec. 1036.730. The emission credits used to address
the deficit may come from your other engine families that generate
emission credits in the same model
[[Page 36354]]
year, from emission credits you have banked, or from emission credits
you obtain through trading.
0
103. Amend Sec. 1036.720 by revising paragraph (c) to read as follows:
Sec. 1036.720 Trading.
* * * * *
(c) If a negative emission credit balance results from a
transaction, both the buyer and seller are liable, except in cases we
deem to involve fraud. See Sec. 1036.255(e) for cases involving fraud.
We may void the certificates of all engine families participating in a
trade that results in a manufacturer having a negative balance of
emission credits.
0
104. Revise Sec. 1036.725 to read as follows:
Sec. 1036.725 Required information for certification.
(a) You must declare in your application for certification your
intent to use the provisions of this subpart for each engine family
that will be certified using the ABT program. You must also declare the
FEL you select for the engine family for each pollutant for which you
are using the ABT program. Your FELs must comply with the
specifications of subpart B of this part, including the FEL caps.
(b) Include the following in your application for certification:
(1) A statement that, to the best of your belief, you will not have
a negative balance of emission credits for any averaging set when all
emission credits are calculated at the end of the year.
(2) Calculations of projected emission credits (positive or
negative) based on projected production volumes as described in Sec.
1036.705(c). We may require you to include similar calculations from
your other engine families to project your net credit balances for the
model year. If you project negative emission credits for a family,
state the source of positive emission credits you expect to use to
offset the negative emission credits.
0
105. Amend Sec. 1036.730 by revising paragraphs (b)(3) and (4),
(c)(1), and (f)(1) to read as follows:
Sec. 1036.730 ABT reports.
* * * * *
(b) * * *
(3) The FEL for each pollutant. If you change the FEL after the
start of production, identify the date that you started using the new
FEL and/or give the engine identification number for the first engine
covered by the new FEL. In this case, identify each applicable FEL and
calculate the positive or negative emission credits as specified in
Sec. 1036.225(f).
(4) The projected and actual production volumes for calculating
emission credits for the model year. If you changed an FEL during the
model year, identify the actual production volume associated with each
FEL.
* * * * *
(c) * * *
(1) Show that your net balance of emission credits from all your
participating engine families in each averaging set in the applicable
model year is not negative. Your credit tracking must account for the
limitation on credit life under Sec. 1036.740(d).
* * * * *
(f) * * *
(1) If you notify us by the deadline for submitting the final
report that errors mistakenly decreased your balance of emission
credits, you may correct the errors and recalculate the balance of
emission credits.
* * * * *
0
106. Amend Sec. 1036.735 by revising paragraph (d) to read as follows:
Sec. 1036.735 Recordkeeping.
* * * * *
(d) Keep appropriate records to document production volumes of
engines that generate or use emission credits under the ABT program.
For example, keep available records of the engine identification number
(usually the serial number) for each engine you produce that generates
or uses emission credits. You may identify these numbers as a range. If
you change the FEL after the start of production, identify the date you
started using each FEL and the range of engine identification numbers
associated with each FEL. You must also identify the purchaser and
destination for each engine you produce to the extent this information
is available.
* * * * *
0
107. Amend Sec. 1036.740 by removing and reserving paragraphs (b) and
(c) and revising paragraph (d) to read as follows:
Sec. 1036.740 Restrictions for using emission credits.
* * * * *
(d) NOX credit life. NOX credits may be used only for
five model years after the year in which they are generated. For
example, credits you generate in model year 2027 may be used to
demonstrate compliance with emission standards only through model year
2032.
* * * * *
Sec. 1036.745 [Removed]
0
108. Remove Sec. 1036.745.
0
109. Amend Sec. 1036.750 by revising paragraph (b) to read as follows:
Sec. 1036.750 Consequences for noncompliance.
* * * * *
(b) You may certify your engine family to an FEL above an
applicable standard based on a projection that you will have enough
emission credits to offset the deficit for the engine family.
* * * * *
Sec. 1036.755 [Removed]
0
110. Remove Sec. 1036.755.
0
111. Revise and republish Sec. 1036.801 to read as follows:
Sec. 1036.801 Definitions.
The following definitions apply to this part. The definitions apply
to all subparts unless we note otherwise. All undefined terms have the
meaning the Act gives to them. The definitions follow:
Act means the Clean Air Act, as amended, 42 U.S.C. 7401-7671q.
Adjustable parameter has the meaning given in 40 CFR 1068.50.
Aftertreatment means relating to a catalytic converter, particulate
filter, or any other system, component, or technology mounted
downstream of the exhaust valve (or exhaust port) whose design function
is to decrease emissions in the engine exhaust before it is exhausted
to the environment. Exhaust gas recirculation (EGR) and turbochargers
are not aftertreatment.
Aircraft means any vehicle capable of sustained air travel more
than 100 feet above the ground.
Alcohol-fueled engine mean an engine that is designed to run using
an alcohol fuel. For purposes of this definition, alcohol fuels do not
include fuels with a nominal alcohol content below 25 percent by
volume.
Automated manual transmission (AMT) means a transmission that
operates mechanically similar to a manual transmission, except that an
automated clutch actuator controlled by the onboard computer disengages
and engages the drivetrain instead of a human driver. An automated
manual transmission does not include a torque converter or a clutch
pedal controllable by the driver.
Automatic transmission (AT) means a transmission with a torque
converter (or equivalent) that uses computerize or other internal
controls to shift gears in response to a single driver input for
controlling vehicle speed. Note that automatic manual transmissions are
not automatic transmissions because they do not include torque
converters.
Auxiliary emission control device means any element of design that
senses
[[Page 36355]]
temperature, motive speed, engine speed (r/min), transmission gear, or
any other parameter for the purpose of activating, modulating,
delaying, or deactivating the operation of any part of the emission
control system.
Averaging set has the meaning given in Sec. 1036.740.
Axle ratio or Drive axle ratio, ka, means the
dimensionless number representing the angular speed of the transmission
output shaft divided by the angular speed of the drive axle.
Calibration means the set of specifications and tolerances specific
to a particular design, version, or application of a component or
assembly capable of functionally describing its operation over its
working range.
Carbon-containing fuel has the meaning given in 40 CFR 1065.1001.
Carryover means relating to certification based on emission data
generated from an earlier model year as described in Sec. 1036.235(d).
Certification means relating to the process of obtaining a
certificate of conformity for an engine family that complies with the
emission standards and requirements in this part.
Certified emission level means the highest deteriorated emission
level in an engine family for a given pollutant from the applicable
transient and/or steady-state testing, rounded to the same number of
decimal places as the applicable standard.
Charge-depleting has the meaning given in 40 CFR 1066.1001.
Charge-sustaining has the meaning given in 40 CFR 1066.1001.
Complete vehicle means a vehicle meeting the definition of complete
vehicle in 40 CFR 1037.801 when it is first sold as a vehicle. For
example, where a vehicle manufacturer sells an incomplete vehicle to a
secondary vehicle manufacturer, the vehicle is not a complete vehicle
under this part, even after its final assembly.
Compression-ignition means relating to a type of reciprocating,
internal-combustion engine that is not a spark-ignition engine. Note
that Sec. 1036.1 also deems gas turbine engines and other engines to
be compression-ignition engines.
Crankcase emissions means airborne substances emitted to the
atmosphere from any part of the engine crankcase's ventilation or
lubrication systems. The crankcase is the housing for the crankshaft
and other related internal parts.
Critical emission-related component has the meaning given in 40 CFR
1068.30.
Defeat device has the meaning given in Sec. 1036.115(h).
Designated Compliance Officer means one of the following:
(1) For engines subject to compression-ignition standards,
Designated Compliance Officer means Director, Diesel Engine Compliance
Center, U.S. Environmental Protection Agency, 2000 Traverwood Drive,
Ann Arbor, MI 48105; [email protected]; www.epa.gov/ve-certification.
(2) For engines subject to spark-ignition standards, Designated
Compliance Officer means Director, Gasoline Engine Compliance Center,
U.S. Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor,
MI 48105; [email protected]; www.epa.gov/ve-certification.
Deteriorated emission level means the emission level that results
from applying the appropriate deterioration factor to the official
emission result of the emission-data engine. Note that where no
deterioration factor applies, references in this part to the
deteriorated emission level mean the official emission result.
Deterioration factor means the relationship between emissions at
the end of useful life (or point of highest emissions if it occurs
before the end of useful life) and emissions at the low-hour/low-
mileage point, expressed in one of the following ways:
(1) For multiplicative deterioration factors, the ratio of
emissions at the end of useful life (or point of highest emissions) to
emissions at the low-hour point.
(2) For additive deterioration factors, the difference between
emissions at the end of useful life (or point of highest emissions) and
emissions at the low-hour point.
Diesel exhaust fluid (DEF) means a liquid reducing agent (other
than the engine fuel) used in conjunction with selective catalytic
reduction to reduce NOX emissions. Diesel exhaust fluid is
generally understood to be an aqueous solution of urea conforming to
the specifications of ISO 22241.
Drive idle means idle operation during which the vehicle operator
remains in the vehicle cab, as evidenced by engaging the brake or
clutch pedals, or by other indicators we approve.
Dual-fuel means relating to an engine designed for operation on two
different types of fuel but not on a continuous mixture of those fuels
(see Sec. 1036.601(d)). For purposes of this part, such an engine
remains a dual-fuel engine even if it is designed for operation on
three or more different fuels.
Electronic control module (ECM) means an engine's electronic device
that uses data from engine sensors to control engine parameters.
Emergency vehicle means a vehicle that meets one of the following
criteria:
(1) It is an ambulance or a fire truck.
(2) It is a vehicle that we have determined will likely be used in
emergency situations where emission control function or malfunction may
cause a significant risk to human life. For example, we would consider
a truck that is certain to be retrofitted with a slip-on firefighting
module to become an emergency vehicle, even though it was not initially
designed to be a fire truck. Also, a mobile command center that is
unable to manually regenerate its DPF while on duty could be an
emergency vehicle. In making this determination, we may consider any
factor that has an effect on the totality of the actual risk to human
life. For example, we may consider how frequently a vehicle will be
used in emergency situations or how likely it is that the emission
controls will cause a significant risk to human life when the vehicle
is used in emergency situations. We would not consider the truck in the
example above to be an emergency vehicle if there is merely a
possibility (rather than a certainty) that it will be retrofitted with
a slip-on firefighting module.
Emission control system means any device, system, or element of
design that controls or reduces the emissions of regulated pollutants
from an engine.
Emission-data engine means an engine that is tested for
certification. This includes engines tested to establish deterioration
factors.
Emission-related component has the meaning given in 40 CFR part
1068, appendix A.
Emission-related maintenance means maintenance that substantially
affects emissions or is likely to substantially affect emission
deterioration.
Engine configuration means a unique combination of engine hardware
and calibration (related to the emission standards) within an engine
family, which would include hybrid components for engines certified as
hybrid engines and hybrid powertrains. Engines within a single engine
configuration differ only with respect to normal production variability
or factors unrelated to compliance with emission standards.
Engine family has the meaning given in Sec. 1036.230.
Excluded means relating to engines that are not subject to some or
all of the requirements of this part as follows:
(1) An engine that has been determined not to be a heavy-duty
engine is excluded from this part.
[[Page 36356]]
(2) Certain heavy-duty engines are excluded from the requirements
of this part under Sec. 1036.5.
(3) Specific regulatory provisions of this part may exclude a
heavy-duty engine generally subject to this part from one or more
specific standards or requirements of this part.
Exempted has the meaning given in 40 CFR 1068.30.
Exhaust gas recirculation means a technology that reduces emissions
by routing exhaust gases that had been exhausted from the combustion
chamber(s) back into the engine to be mixed with incoming air before or
during combustion. The use of valve timing to increase the amount of
residual exhaust gas in the combustion chamber(s) that is mixed with
incoming air before or during combustion is not considered exhaust gas
recirculation for the purposes of this part.
Family emission limit (FEL) means a NOX emission level
declared by the manufacturer to serve in place of an otherwise
applicable emission standard under the ABT program in subpart H of this
part. The FEL serves as the emission standard for the engine family
with respect to all required testing.
Federal Test Procedure (FTP) means the applicable transient duty
cycle described in Sec. 1036.512 designed to measure exhaust emissions
during urban driving.
Final drive ratio, kd, means the dimensionless number
representing the angular speed of the transmission input shaft divided
by the angular speed of the drive axle when the vehicle is operating in
its highest available gear. The final drive ratio is the transmission
gear ratio (in the highest available gear) multiplied by the drive axle
ratio.
Flexible-fuel means relating to an engine designed for operation on
any mixture of two or more different types of fuels (see Sec.
1036.601(d)).
Fuel type means a general category of fuels such as diesel fuel,
gasoline, or natural gas. There can be multiple grades within a single
fuel type, such as premium gasoline, regular gasoline, or gasoline with
10 percent ethanol.
Gear ratio or Transmission gear ratio, kg, means the
dimensionless number representing the angular speed of the
transmission's input shaft divided by the angular speed of the
transmission's output shaft when the transmission is operating in a
specific gear.
Good engineering judgment has the meaning given in 40 CFR 1068.30.
See 40 CFR 1068.5 for the administrative process we use to evaluate
good engineering judgment.
Greenhouse gas Emissions Model (GEM) means the GEM simulation tool
referenced in Sec. 1036.810.
Gross vehicle weight rating (GVWR) means the value specified by the
vehicle manufacturer as the maximum design loaded weight of a single
vehicle, consistent with good engineering judgment.
Heavy-duty engine means any engine which the engine manufacturer
could reasonably expect to be used for motive power in a heavy-duty
vehicle. For purposes of this definition in this part, the term
``engine'' includes internal combustion engines and other devices that
convert chemical fuel into motive power. For example, a gas turbine
used in a heavy-duty vehicle is a heavy-duty engine.
Heavy-duty vehicle means any motor vehicle above 8,500 pounds GVWR.
An incomplete vehicle is also a heavy-duty vehicle if it has a curb
weight above 6,000 pounds or a basic vehicle frontal area greater than
45 square feet. Curb weight and basic vehicle frontal area have the
meaning given in 40 CFR 86.1803-01.
Hybrid means relating to an engine or powertrain that includes a
Rechargeable Energy Storage System. Hybrid engines store and recover
energy in a way that is integral to the engine or otherwise upstream of
the vehicle's transmission. Examples of hybrid engines include engines
with hybrid components connected to the front end of the engine (P0),
connected to the crankshaft before the clutch (P1), or connected
between the clutch and the transmission where the clutch upstream of
the hybrid feature is in addition to the transmission clutch or
clutches (P2). Engine-based systems that recover kinetic energy to
power an electric heater in the aftertreatment are themselves not
sufficient to qualify as a hybrid engine. The provisions in this part
that apply for hybrid powertrains apply equally for hybrid engines,
except as specified. Note that certain provisions in this part treat
hybrid powertrains intended for vehicles that include regenerative
braking different than those intended for vehicles that do not include
regenerative braking. The definition of hybrid includes plug-in hybrid
electric powertrains.
Hydrocarbon (HC) has the meaning given in 40 CFR 1065.1001.
Identification number means a unique specification (for example, a
model number/serial number combination) that allows someone to
distinguish a particular engine from other similar engines.
Incomplete vehicle means a vehicle meeting the definition of
incomplete vehicle in 40 CFR 1037.801 when it is first sold (or
otherwise delivered to another entity) as a vehicle.
Liquefied petroleum gas (LPG) means a liquid hydrocarbon fuel that
is stored under pressure and is composed primarily of nonmethane
compounds that are gases at atmospheric conditions. Note that, although
this commercial term includes the word ``petroleum'', LPG is not
considered to be a petroleum fuel under the definitions of this
section.
Low-hour means relating to an engine that has stabilized emissions
and represents the undeteriorated emission level. This would generally
involve less than 300 hours of operation for engines with
NOX aftertreatment and 125 hours of operation for other
engines.
Manual transmission (MT) means a transmission that requires the
driver to shift the gears and manually engage and disengage the clutch.
Manufacture means the physical and engineering process of
designing, constructing, and/or assembling a heavy-duty engine or a
heavy-duty vehicle.
Manufacturer has the meaning given in 40 CFR 1068.30.
Medium-duty passenger vehicle has the meaning given in 40 CFR
86.1803.
Model year means the manufacturer's annual new model production
period, except as restricted under this definition. It must include
January 1 of the calendar year for which the model year is named, may
not begin before January 2 of the previous calendar year, and it must
end by December 31 of the named calendar year. Manufacturers may not
adjust model years to circumvent or delay compliance with emission
standards or to avoid the obligation to certify annually.
Motorcoach means a heavy-duty vehicle designed for carrying 30 or
more passengers over long distances. Such vehicles are characterized by
row seating, rest rooms, and large luggage compartments, and facilities
for stowing carry-on luggage.
Motor vehicle has the meaning given in 40 CFR 85.1703.
Natural gas means a fuel whose primary constituent is methane.
Neat has the meaning given in 40 CFR 1065.1001.
New motor vehicle engine has the meaning given in the Act. This
generally means a motor vehicle engine meeting any of the following:
(1) A motor vehicle engine for which the ultimate purchaser has
never received the equitable or legal title is a new motor vehicle
engine. This kind of engine might commonly be thought of as ``brand
new'' although a new motor
[[Page 36357]]
vehicle engine may include previously used parts. Under this
definition, the engine is new from the time it is produced until the
ultimate purchaser receives the title or places it into service,
whichever comes first.
(2) An imported motor vehicle engine is a new motor vehicle engine
if it was originally built on or after January 1, 1970.
(3) Any motor vehicle engine installed in a new motor vehicle.
Noncompliant engine means an engine that was originally covered by
a certificate of conformity, but is not in the certified configuration
or otherwise does not comply with the conditions of the certificate.
Nonconforming engine means an engine not covered by a certificate
of conformity that would otherwise be subject to emission standards.
Nonmethane hydrocarbon (NMHC) means the sum of all hydrocarbon
species except methane, as measured according to 40 CFR part 1065.
Nonmethane hydrocarbon equivalent (NMHCE) has the meaning given in
40 CFR 1065.1001.
Nonmethane nonethane hydrocarbon equivalent (NMNEHC) has the
meaning given in 40 CFR 1065.1001.
Official emission result means the measured emission rate for an
emission-data engine on a given duty cycle before the application of
any deterioration factor, but after the applicability of any required
regeneration or other adjustment factors.
Owners manual means a document or collection of documents prepared
by the engine or vehicle manufacturer for the owner or operator to
describe appropriate engine maintenance, applicable warranties, and any
other information related to operating or keeping the engine. The
owners manual is typically provided to the ultimate purchaser at the
time of sale. The owners manual may be in paper or electronic format.
Oxides of nitrogen has the meaning given in 40 CFR 1065.1001.
Percent has the meaning given in 40 CFR 1065.1001. Note that this
means percentages identified in this part are assumed to be infinitely
precise without regard to the number of significant figures. For
example, one percent of 1,493 is 14.93.
Placed into service means put into initial use for its intended
purpose, excluding incidental use by the manufacturer or a dealer.
Preliminary approval means approval granted by an authorized EPA
representative prior to submission of an application for certification,
consistent with the provisions of Sec. 1036.210.
Primary intended service class has the meaning given in Sec.
1036.140.
Rechargeable Energy Storage System (RESS) has the meaning given in
40 CFR 1065.1001.
Relating to as used in this section means relating to something in
a specific, direct manner. This expression is used in this section only
to define terms as adjectives and not to broaden the meaning of the
terms.
Revoke has the meaning given in 40 CFR 1068.30.
Round has the meaning given in 40 CFR 1065.1001.
Sample means the collection of engines selected from the population
of an engine family for emission testing. This may include testing for
certification, production-line testing, or in-use testing.
Scheduled maintenance means adjusting, removing, disassembling,
cleaning, or replacing components or systems periodically to keep a
part or system from failing, malfunctioning, or wearing prematurely.
Small manufacturer means a manufacturer meeting the criteria
specified in 13 CFR 121.201. The employee and revenue limits apply to
the total number of employees and total revenue together for all
affiliated companies (as defined in 40 CFR 1068.30). Note that
manufacturers with low production volumes may or may not be ``small
manufacturers''.
Spark-ignition means relating to a gasoline-fueled engine or any
other type of engine with a spark plug (or other sparking device) and
with operating characteristics significantly similar to the theoretical
Otto combustion cycle. Spark-ignition engines usually use a throttle to
regulate intake air flow to control power during normal operation.
Stop-start means a vehicle technology that automatically turns the
engine off when the vehicle is stopped.
Steady-state has the meaning given in 40 CFR 1065.1001. This
includes idle testing where engine speed and load are held at a finite
set of nominally constant values.
Suspend has the meaning given in 40 CFR 1068.30.
Test engine means an engine in a sample.
Ultimate purchaser means, with respect to any new engine or
vehicle, the first person who in good faith purchases such new engine
or vehicle for purposes other than resale.
United States has the meaning given in 40 CFR 1068.30.
Upcoming model year means for an engine family the model year after
the one currently in production.
U.S.-directed production volume means the number of engines,
subject to the requirements of this part, produced by a manufacturer
for which the manufacturer has a reasonable assurance that sale was or
will be made to ultimate purchasers in the United States.
Vehicle has the meaning given in 40 CFR 1037.801.
Void has the meaning given in 40 CFR 1068.30.
We (us, our) means the Administrator of the Environmental
Protection Agency and any authorized representatives.
Sec. 1036.805 [Amended]
0
112. Amend Sec. 1036.805 by revising Table 5 to Paragraph (e) to
remove entries for ``FCL'', ``Heavy HDV'', ``Light HDV'', and ``Medium
HDV''.
Sec. 1036.810 [Amended]
0
113. Amend Sec. 1036.810 by removing and reserving paragraphs (a)(2)
and (3).
0
114. Amend Sec. 1036.815 by revising paragraph (b) to read as follows:
Sec. 1036.815 Confidential information.
* * * * *
(b) Emission data or information that is publicly available cannot
be treated as confidential business information as described in 40 CFR
1068.11.
Appendix C to Part 1036 [Removed]
0
115. Remove appendix C to part 1036.
PART 1037--CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES
0
116. The authority citation for part 1036 continues to read as follows:
Authority: 42 U.S.C. 7401-7671q.
Sec. 1037.5 [Amended]
0
117. Amend Sec. 1037.5 by removing and reserving paragraphs (c) and
(d).
0
118. Amend Sec. 1037.10 by revising paragraph (b) and removing and
reserving paragraphs (d) through (f) and (h). The revision reads as
follows:
Sec. 1037.10 How is this part organized?
* * * * *
(b) Subpart B of this part describes the emission standards and
other requirements that must be met to certify vehicles under this
part.
* * * * *
0
119. Amend Sec. 1037.15 by revising paragraph (a) to read as follows:
Sec. 1037.15 Do any other regulation parts apply to me?
(a) Parts 1065 and 1066 of this chapter describe procedures and
equipment specifications for testing engines and vehicles to measure
exhaust emissions.
* * * * *
[[Page 36358]]
Sec. 1037.101 [Amended]
0
120. Amend Sec. 1037.101 by removing and reserving paragraphs (a)(2)
and (b)(2).
0
121. Revise and republish Sec. 1037.102 to read as follows:
Sec. 1037.102 Criteria pollutant exhaust emission standards--NOX, HC,
PM, and CO.
(a) Engines installed in heavy-duty vehicles are subject to
criteria pollutant standards for NOX, HC, PM, and CO under
40 CFR part 86 through model year 2026 and 40 CFR part 1036 for model
years 2027 and later.
(1) The following vehicles are deemed to meet the criteria
pollutant exhaust emission standards of this part and you may state in
the application for certification that your vehicles comply with all
the requirements of this part related to criteria pollutant exhaust
emission standards instead of submitting test data:
(i) Model year 2026 and earlier vehicles with installed engines
certified to the standards specified in 40 CFR 86.007-11 or 86.008-10.
(ii) Model year 2027 and later vehicles with installed engines
certified to the standards specified in 40 CFR part 1036.
(iii) Specialty vehicles with installed engines certified as
specified in Sec. 1037.605.
(iv) Glider kits and glider vehicles with installed engines
certified as specified in Sec. 1037.635.
(2) This part includes additional specific requirements for the
following types of vehicles:
(i) New tractors that include auxiliary power units. See paragraph
(c) of this section.
(ii) Vehicles subject to evaporative or refueling standards under
Sec. 1037.103.
(b) Heavy-duty vehicles with no installed propulsion engine, such
as battery electric vehicles, are subject to criteria pollutant
standards under this part. The emission standards that apply are the
same as the standards that apply for compression-ignition engines under
40 CFR 86.007-11 or 1036.104 for a given model year.
(1) You may state in the application for certification that
vehicles with no installed propulsion engine comply with all the
requirements of this part related to criteria emission standards
instead of submitting test data. Tailpipe emissions of criteria
pollutants from vehicles with no installed propulsion engine are deemed
to be zero.
(2) Vehicles with no installed propulsion engines may not generate
NOX credits.
(c) Starting in model year 2024, auxiliary power units installed on
new tractors, including tractors that are glider vehicles or tractors
with no installed propulsion engine, must be certified to the PM
emission standard specified in 40 CFR 1039.699. For model years 2021
through 2023, the APU engine must be certified under 40 CFR part 1039
with a deteriorated emission level for PM at or below 0.15 g/kW-hr.
Selling, offering for sale, or introducing or delivering into commerce
in the United States or importing into the United States a new tractor
subject to this standard is a violation of 40 CFR 1068.101(a)(1) unless
the auxiliary power unit has a valid certificate of conformity and the
required label showing that it meets the PM standard specified in 40
CFR 1039.699 as described in this paragraph (c).
Sec. Sec. 1037.105 and 1037.106 [Removed]
0
122. Remove Sec. Sec. 1037.105 and 1037.106.
Sec. 1037.115 [Amended]
0
123. Amend Sec. 1037.115 by removing paragraphs (e) and (f).
0
124. Amend Sec. 1037.120 by revising paragraphs (a), (b), and (c) to
read as follows:
Sec. 1037.120 Emission-related warranty requirements.
(a) General requirements. You must warrant to the ultimate
purchaser and each subsequent purchaser that each new vehicle,
including all parts of its emission control system, meets two
conditions:
(1) It is designed, built, and equipped so it conforms at the time
of sale to the ultimate purchaser with the requirements of this part.
(2) It is free from defects in materials and workmanship that cause
the vehicle to fail to conform to the requirements of this part during
the applicable warranty period.
(b) Warranty period. (1) Your emission-related warranty must be
valid for at least:
(i) 5 years or 50,000 miles for heavy-duty vehicles at or below
19,500 pounds GVWR.
(ii) 5 years or 100,000 miles for heavy-duty vehicles above 19,500
pounds GVWR.
(2) You may offer an emission-related warranty more generous than
we require. The emission-related warranty for the vehicle may not be
shorter than any basic mechanical warranty you provide to that owner
without charge for the vehicle. Similarly, the emission-related
warranty for any component may not be shorter than any warranty you
provide to that owner without charge for that component. This means
that your warranty for a given vehicle may not treat emission-related
and nonemission-related defects differently for any component. The
warranty period begins when the vehicle is placed into service.
(c) Components covered. The emission-related warranty covers fuel
cell stacks, RESS, and other components used with battery electric
vehicles and fuel cell electric vehicles. The emission-related warranty
covers all components whose failure would increase a vehicle's
evaporative and refueling emissions (for vehicles subject to
evaporative and refueling emission standards). The emission-related
warranty covers components that are part of your certified
configuration even if another company produces the component.
* * * * *
0
125. Revise Sec. 1037.125 to read as follows:
Sec. 1037.125 Maintenance instructions and allowable maintenance.
Give the ultimate purchaser of each new vehicle written
instructions for properly maintaining and using the vehicle with
respect to evaporative and refueling emission control system, as
applicable.
0
126. Amend Sec. 1037.135 by removing and reserving paragraphs (c)(6)
and (7) and revising paragraph (e). The revision reads as follows:
Sec. 1037.135 Labeling.
* * * * *
(e) You may ask us to approve modified labeling requirements in
this part 1037 if you show that it is necessary or appropriate. For
example, if you certify both the engine and vehicle, you may ask for
approval to comply with labeling requirements with a single emission
control information label. We will approve your request if your
alternate label is consistent with the requirements of this part.
Sec. Sec. 1037.140 and 1037.150 [Removed]
0
127. Remove Sec. Sec. 1037.140 and 1037.150.
0
128. Amend Sec. 1037.201 by removing and reserving paragraph (g) and
revising paragraph (i). The revision reads as follows:
Sec. 1037.201 General requirements for obtaining a certificate of
conformity.
* * * * *
(i) Vehicles and installed engines must meet exhaust, evaporative,
and refueling emission standards and certification requirements as
described in Sec. Sec. 1037.102 and 1037.103, as applicable. Include
the information described in 40 CFR part 86, subpart S, or 40 CFR
1036.205 in your application
[[Page 36359]]
for certification in addition to what we specify in Sec. 1037.205 so
we can issue a single certificate of conformity for all the
requirements that apply for your vehicle and the installed engine.
0
129. Revise Sec. 1037.205 to read as follows:
Sec. 1037.205 What must I include in my application?
This section specifies the information that must be in your
application, unless we ask you to include less information under Sec.
1037.201(c). We may require you to provide additional information to
evaluate your application.
(a) List the fuel type on which your vehicles are designed to
operate (for example, diesel fuel or gasoline).
(b) For vehicles with propulsion engines, name all the engine
families associated with the vehicle family.
(c) For any new tractors with auxiliary power units, name all the
engine families associated with those auxiliary power units.
(d) For any vehicle using RESS (such as hybrid vehicles, fuel cell
electric vehicles and battery electric vehicles), describe in detail
all components needed to charge the system, store energy, and transmit
power to move the vehicle.
(e) For vehicles subject to evaporative and refueling emission
standards, include the following information:
(1) Describe the vehicle family's specifications and other basic
parameters of the vehicle's design and emission controls. Explain how
the emission control system operates. As applicable, describe in detail
all system components for controlling emissions, including all
auxiliary emission control devices (AECDs) and all fuel-system
components you will install on any production vehicle. Identify the
part number of each component you describe. For this paragraph (e),
treat as separate AECDs any devices that modulate or activate
differently from each other.
(2) Where applicable, describe all adjustable operating parameters
(see Sec. 1037.115), including production tolerances. For any
operating parameters that do not qualify as adjustable parameters,
include a description supporting your conclusion (see 40 CFR
1068.50(c)). Include the following in your description of each
adjustable parameter:
(i) The nominal or recommended setting.
(ii) The intended practically adjustable range.
(iii) The limits or stops used to establish adjustable ranges.
(iv) Information showing why the limits, stops, or other means of
inhibiting adjustment are effective in preventing adjustment of
parameters on in-use engines to settings outside your intended
practically adjustable ranges.
(3) Identify the vehicle family's useful life.
(4) Describe your engineering analysis to demonstrate compliance
with standards as described in Sec. 1037.103(c), or include the
following testing information:
(i) Describe any vehicles or components you selected for testing
and the reasons for selecting them.
(ii) Describe any test equipment and procedures that you used,
including any special or alternate test procedures you used.
(iii) Describe how you operated any emission-data vehicle before
testing, including the duty cycle and the number of vehicle operating
miles used to stabilize emission-related performance. Explain why you
selected the method of service accumulation. Describe any scheduled
maintenance you did, and any practices or specifications that should
apply for our testing.
(iv) List the specifications of any test fuel to show that it falls
within the required ranges we specify in 40 CFR part 1065.
(v) Identify the emission standards or FELs to which you are
certifying vehicles in the vehicle family.
(vi) Where applicable, identify the vehicle family's deterioration
factors and describe how you developed them. Present any emission test
data you used for this.
(vii) Where applicable, state that you operated your emission-data
vehicles as described in the application (including the test
procedures, test parameters, and test fuels) to show you meet the
requirements of this part.
(f) Include any maintenance instructions and warranty statements
you will give to the ultimate purchaser of each new vehicle (see
Sec. Sec. 1037.120 and 1037.125).
(g) Describe your emission control information label (see Sec.
1037.135).
(h) Unconditionally certify that all the vehicles in the vehicle
family comply with the requirements of this part, other referenced
parts of the CFR, and the Clean Air Act.
(i) Include good-faith estimates of U.S.-directed production
volumes. We may require you to describe the basis of your estimates.
(j) Include other applicable information, such as information
specified in this part or 40 CFR part 1068 related to requests for
exemptions.
(k) Name an agent for service located in the United States. Service
on this agent constitutes service on you or any of your officers or
employees for any action by EPA or otherwise by the United States
related to the requirements of this part.
0
130. Amend Sec. 1037.225 by revising paragraphs (a)(1) and (f) to read
as follows:
Sec. 1037.225 Amending applications for certification.
* * * * *
(a) * * *
(1) Add any vehicle configurations to a vehicle family that are not
already covered by your application. For example, if your application
identifies three possible engine models, and you plan to produce
vehicles using an additional engine model, then you must amend your
application before producing vehicles with the fourth engine model.
* * * * *
(f) You may ask us to approve a change to your FEL in certain cases
after the start of production. The changed FEL may not apply to
vehicles you have already introduced into U.S. commerce, except as
described in this paragraph (f). You may ask us to approve a change to
your FEL in the following cases:
(1) You may ask to raise your FEL for your vehicle family at any
time. In your request, you must show that you will still be able to
meet the emission standards as specified in subparts B and H of this
part. Use the appropriate FELs with corresponding production volumes to
calculate emission credits for the model year, as described in subpart
H of this part.
(2) Where testing applies, you may ask to lower the FEL for your
vehicle family only if you have test data from production vehicles
showing that emissions are below the proposed lower FEL. Otherwise, you
may ask to lower your FEL for your vehicle family at any time. The
lower FEL applies only to vehicles you produce after we approve the new
FEL. Use the appropriate FELs with corresponding production volumes to
calculate emission credits for the model year, as described in subpart
H of this part.
(3) You may ask to add an FEL for your vehicle family at any time.
* * * * *
0
131. Revise Sec. 1037.230 to read as follows:
Sec. 1037.230 Vehicle families.
For purposes of certifying your vehicles, divide your product line
into vehicle families as follows:
(a) All vehicles identified in Sec. 1037.102(a)(1)(i) and (ii) for
a given
[[Page 36360]]
model year may be in a single vehicle family, except as follows:
(1) New tractors with auxiliary power units need to be in a
separate vehicle family.
(2) Divide vehicles subject to evaporative or refueling standards
into vehicle families as described in 40 CFR 86.1821.
(b) All specialty vehicles identified in Sec. 1037.102(a)(1)(iii)
for a given model year may be in a single vehicle family.
(c) All glider kits and glider vehicles in Sec. 1037.102(a)(1)(iv)
for a given model year may be in a single vehicle family.
(d) All vehicles with no installed propulsion engine for a given
model year may be in a single vehicle family, except that new tractors
with auxiliary power units must be in a separate vehicle family.
Sec. Sec. 1037.231 and 1036.232 [Removed]
0
132. Remove Sec. Sec. 1037.231 and 1037.232.
0
133. Revise and republish Sec. 1037.235 to read as follows:
Sec. 1037.235 Testing requirements for certification.
This section describes the emission testing you must perform to
show compliance with respect to the standards in subpart B of this
part, and to determine any input values.
(a) Select emission-data vehicles that represent production
vehicles and components for the vehicle family. Where the test results
will represent multiple vehicles or components with different emission
performance, use good engineering judgment to select worst-case
emission data vehicles or components.
(b) Test your emission-data vehicles (including emission-data
components) using the procedures and equipment referenced in subpart B
of this part. Measure emissions (or other parameters, as applicable)
using the specified procedures.
(c) We may perform confirmatory testing by measuring emissions (or
other parameters, as applicable) from any of your emission-data
vehicles.
(1) We may decide to do the testing at your plant or any other
facility. If we do this, you must deliver the vehicle or component to a
test facility we designate. The vehicle or component you provide must
be in a configuration that is suitable for testing. If we do the
testing at your plant, you must schedule it as soon as possible and
make available the instruments, personnel, and equipment we need (see
paragraph (g) of this section for provisions that apply specifically
for testing a tractor's aerodynamic performance).
(2) If we measure emissions (or other parameters, as applicable)
from your vehicle or component, the results of that testing become the
official emission results for the vehicle or component. Note that
changing the official emission result does not necessarily require a
change in the declared modeling input value. Unless we later invalidate
these data, we may decide not to consider your data in determining if
your vehicle family meets applicable requirements in this part.
(3) Before we test one of your vehicles or components, we may set
its adjustable parameters to any point within the practically
adjustable ranges, if applicable.
(4) Before we test one of your vehicles or components, we may
calibrate it within normal production tolerances for anything we do not
consider an adjustable parameter. For example, this would apply for a
vehicle parameter that is subject to production variability because it
is adjustable during production, but is not considered an adjustable
parameter (as defined in Sec. 1037.801) because it is permanently
sealed. For parameters that relate to a level of performance that is
itself subject to a specified range (such as maximum power output), we
will generally perform any calibration under this paragraph (c)(4) in a
way that keeps performance within the specified range. Note that this
paragraph (c)(4) does not allow us to test your vehicles in a condition
that would be unrepresentative of production vehicles.
(d) You may ask to use carryover data for a vehicle or component
from a previous model year instead of doing new tests if the applicable
emission-data vehicle from the previous model year remains the
appropriate emission-data vehicle under paragraph (b) of this section.
(e) We may require you to test a second vehicle or component of the
same configuration in addition to the vehicle or component tested under
paragraph (a) of this section.
(f) If you use an alternate test procedure under 40 CFR 1065.10 and
later testing shows that such testing does not produce results that are
equivalent to the procedures referenced in subpart B of this part, we
may reject data you generated using the alternate procedure.
Sec. 1037.241 [Removed]
0
134. Remove Sec. 1037.241.
0
135. Amend Sec. 1037.250 by revising paragraph (a) to read as follows:
Sec. 1037.250 Reporting and recordkeeping.
(a) By September 30 following the end of the model year, send the
Designated Compliance Officer a report including the total U.S.-
directed production volume of vehicles you produced in each vehicle
family during the model year (based on information available at the
time of the report) by engine family. Report uncertified vehicles sold
to secondary vehicle manufacturers. We may waive the reporting
requirements of this paragraph (a) for small manufacturers.
* * * * *
Subparts D through F [Reserved]
0
136. Remove and reserve:
0
a. Subpart D, consisting of Sec. Sec. 1037.301 through 1037.320;
0
b. Subpart E, consisting of Sec. 1037.401; and
0
c. Subpart F, consisting of Sec. Sec. 1037.501 through 1037.570.
0
137. Amend Sec. 1037.601 by revising paragraph (a)(1) to read as
follows:
Sec. 1037.601 General compliance provisions.
(a) * * *
(1) Except as specifically allowed by this part or 40 CFR part
1068, it is a violation of 40 CFR 1068.101(a)(1) to introduce into U.S.
commerce a vehicle containing an engine that is not certified to the
applicable requirements of 40 CFR part 86 or 1036.
* * * * *
0
138. Amend Sec. 1037.605 by revising paragraph (d) to read as follows:
Sec. 1037.605 Installing engines certified to alternate standards for
specialty vehicles.
* * * * *
(d) Vehicle standards. Vehicles qualifying under this section are
subject to evaporative emission standards as specified in Sec.
1037.103, but are exempt from the other requirements of this part,
except as specified in this section and in Sec. 1037.601. These
vehicles must include a label as specified in Sec. 1037.135.
Sec. Sec. 1037.610 and 1037.615 [Removed]
0
139. Remove Sec. Sec. 1037.610 and 1037.615.
0
140. Amend Sec. 1037.620 by revising paragraph (c) introductory text
to read as follows:
Sec. 1037.620 Responsibilities for multiple manufacturers.
* * * * *
(c) Component manufacturers providing test data to certifying
vehicle manufacturers are responsible as follows for test components
and emission test results provided to vehicle
[[Page 36361]]
manufacturers for the purpose of certification under this part:
* * * * *
0
141. Amend Sec. 1037.621 by revising paragraphs (b) and (d)
introductory text and removing paragraph (g). The revisions read as
follows:
Sec. 1037.621 Delegated assembly.
* * * * *
(b) You do not need an exemption to ship a vehicle that does not
include installation or assembly of certain emission-related components
if those components are shipped along with the vehicle. For example,
you may generally ship fuel tanks along with vehicles rather than
installing them on the vehicle before shipment. We may require you to
describe how you plan to use this provision.
* * * * *
(d) Delegated-assembly provisions apply as specified in this
paragraph (d) if the certifying vehicle manufacturer relies on a
secondary vehicle manufacturer to procure and install auxiliary power
units or natural gas fuel tanks. Apply the provisions of 40 CFR
1068.261, with the following exceptions and clarifications:
* * * * *
0
142. Amend Sec. 1037.622 by revising the introductory text and
paragraph (a) and removing paragraph (d). The revisions read as
follows:
Sec. 1037.622 Shipment of partially complete vehicles to secondary
vehicle manufacturers.
This section specifies how manufacturers may introduce partially
complete vehicles into U.S. commerce (or in the case of certain custom
vehicles, introduce complete vehicles into U.S. commerce for
modification by a small manufacturer). The provisions of this section
are intended to accommodate normal business practices without
compromising the effectiveness of certified emission controls. You may
not use the provisions of this section to circumvent the intent of this
part.
(a) The provisions of this section allow manufacturers to ship
partially complete vehicles to secondary vehicle manufacturers or
otherwise introduce them into U.S. commerce in the following
circumstances:
(1) Certified vehicles. Manufacturers may introduce partially
complete tractors into U.S. commerce if they are covered by
certificates of conformity and are in certified configurations. See
Sec. 1037.621 for vehicles not yet in a certified configuration when
introduced into U.S. commerce.
(2) Uncertified vehicles that will be certified by secondary
vehicle manufacturers. Manufacturers may introduce into U.S. commerce
partially complete vehicles for which they do not hold the required
certificate of conformity only as allowed by paragraph (b) of this
section.
(3) Exempted vehicles. Manufacturers may introduce into U.S.
commerce partially complete vehicles without a certificate of
conformity if the vehicles are exempt under this part or under 40 CFR
part 1068. This may involve the secondary vehicle manufacturer
qualifying for the exemption.
* * * * *
Sec. Sec. 1037.630 and 1037.631 [Removed]
0
143. Remove Sec. Sec. 1037.630 and 1037.631.
0
144. Amend Sec. 1037.635 by removing the introductory text and
revising paragraphs (a) and (b). The revision reads as follows:
Sec. 1037.635 Glider kits and glider vehicles.
(a) Vehicles produced from glider kits and other glider vehicles
are subject to the same standards as other new vehicles. For example,
APUs installed on new glider tractors are subject to the certification
requirement described in Sec. 1037.102.
(b) Section 1037.601(a)(1) disallows the introduction into U.S.
commerce of a new vehicle (including a vehicle assembled from a glider
kit) unless it has an engine that is certified to the applicable
standards in 40 CFR parts 86 and 1036. Except as specified otherwise in
this part, the standards apply for engines used in glider vehicles as
follows:
(1) [Reserved]
(2) The engine must meet the criteria pollutant standards of 40 CFR
part 86 or 1036 that apply for the engine model year corresponding to
the vehicle's date of manufacture.
(3) The engine may be from an earlier model year if the standards
were identical to the currently applicable engine standards.
* * * * *
Sec. Sec. 1037.640, 1037.645, 1037.655, 1037.660, 1037.665, and
1037.670 [Removed]
0
145. Remove Sec. Sec. 1037.640, 1037.645, 1037.655, 1037.660,
1037.665, and 1037.670.
Subpart H [Reserved]
0
146. Remove and reserve subpart H, consisting of Sec. Sec. 1037.701
through 1037.755.
0
147. Revise and republish Sec. 1037.801 to read as follows:
Sec. 1037.801 Definitions.
The following definitions apply to this part. The definitions apply
to all subparts unless we note otherwise. All undefined terms have the
meaning the Act gives to them. The definitions follow:
Act means the Clean Air Act, as amended, 42 U.S.C. 7401-7671q.
Adjustable parameter has the meaning given in 40 CFR 1068.30.
Adjusted Loaded Vehicle Weight means the numerical average of
vehicle curb weight and GVWR.
Aftertreatment means relating to a catalytic converter, particulate
filter, or any other system, component, or technology mounted
downstream of the exhaust valve (or exhaust port) whose design function
is to decrease emissions in the vehicle exhaust before it is exhausted
to the environment. Exhaust gas recirculation (EGR) and turbochargers
are not aftertreatment.
Aircraft means any vehicle capable of sustained air travel more
than 100 feet off the ground.
Alcohol-fueled vehicle means a vehicle that is designed to run
using an alcohol fuel. For purposes of this definition, alcohol fuels
do not include fuels with a nominal alcohol content below 25 percent by
volume.
Alternative fuel conversion has the meaning given for clean
alternative fuel conversion in 40 CFR 85.502.
Amphibious vehicle means a motor vehicle that is also designed for
operation on water. Note that high ground clearance that enables a
vehicle to drive through water rather than floating on the water does
not make a vehicle amphibious.
Auxiliary emission control device means any element of design that
senses temperature, motive speed, engine speed (r/min), transmission
gear, or any other parameter for the purpose of activating, modulating,
delaying, or deactivating the operation of any part of the emission
control system.
Auxiliary power unit means a device installed on a vehicle that
uses an engine to provide power for purposes other than to (directly or
indirectly) propel the vehicle.
Battery electric vehicle means a motor vehicle powered solely by an
electric motor where energy for the motor is supplied by one or more
batteries that receive power from an external source of electricity.
Note that this definition does not include hybrid vehicles or plug-in
hybrid electric vehicles.
Calibration means the set of specifications and tolerances specific
to a particular design, version, or application of a component or
assembly
[[Page 36362]]
capable of functionally describing its operation over its working
range.
Carryover means relating to certification based on emission data
generated from an earlier model year.
Certification means relating to the process of obtaining a
certificate of conformity for a vehicle family that complies with the
emission standards and requirements in this part.
Certified emission level means the highest deteriorated emission
level in a vehicle family for a given pollutant from either transient
or steady-state testing.
Class means relating to GVWR classes, as follows:
(1) Class 2b means relating to heavy-duty motor vehicles at or
below 10,000 pounds GVWR.
(2) Class 3 means relating to heavy-duty motor vehicles above
10,000 pounds GVWR but at or below 14,000 pounds GVWR.
(3) Class 4 means relating to heavy-duty motor vehicles above
14,000 pounds GVWR but at or below 16,000 pounds GVWR.
(4) Class 5 means relating to heavy-duty motor vehicles above
16,000 pounds GVWR but at or below 19,500 pounds GVWR.
(5) Class 6 means relating to heavy-duty motor vehicles above
19,500 pounds GVWR but at or below 26,000 pounds GVWR.
(6) Class 7 means relating to heavy-duty motor vehicles above
26,000 pounds GVWR but at or below 33,000 pounds GVWR.
(7) Class 8 means relating to heavy-duty motor vehicles above
33,000 pounds GVWR.
Complete vehicle has the meaning given in the definition for
vehicle in this section.
Compression-ignition has the meaning given in Sec. 1037.101.
Date of manufacture means the date on which the certifying vehicle
manufacturer completes its manufacturing operations, except as follows:
(1) Where the certificate holder is an engine manufacturer that
does not manufacture the chassis, the date of manufacture of the
vehicle is based on the date assembly of the vehicle is completed.
(2) We may approve an alternate date of manufacture based on the
date on which the certifying (or primary) manufacturer completes
assembly at the place of main assembly, consistent with the provisions
of Sec. 1037.601 and 49 CFR 567.4.
Designated Compliance Officer means one of the following:
(1) For compression-ignition engines, Designated Compliance Officer
means Director, Diesel Engine Compliance Center, U.S. Environmental
Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105;
[email protected]; www.epa.gov/ve-certification.
(2) For spark-ignition engines, Designated Compliance Officer means
Director, Gasoline Engine Compliance Center, U.S. Environmental
Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105;
[email protected]; www.epa.gov/ve-certification.
Deteriorated emission level means the emission level that results
from applying the appropriate deterioration factor to the official
emission result of the emission-data vehicle. Note that where no
deterioration factor applies, references in this part to the
deteriorated emission level mean the official emission result.
Deterioration factor means the relationship between the highest
emissions during the useful life and emissions at the low-hour test
point, expressed in one of the following ways:
(1) For multiplicative deterioration factors, the ratio of the
highest emissions to emissions at the low-hour test point.
(2) For additive deterioration factors, the difference between the
highest emissions and emissions at the low-hour test point.
Diesel exhaust fluid (DEF) means a liquid reducing agent (other
than the engine fuel) used in conjunction with selective catalytic
reduction to reduce NOX emissions. Diesel exhaust fluid is
generally understood to be an aqueous solution of urea conforming to
the specifications of ISO 22241.
Dual-fuel means relating to a vehicle or engine designed for
operation on two different fuels but not on a continuous mixture of
those fuels. For purposes of this part, such a vehicle or engine
remains a dual-fuel vehicle or engine even if it is designed for
operation on three or more different fuels.
Electronic control module has the meaning given in 40 CFR
1065.1001.
Emission control system means any device, system, or element of
design that controls or reduces the emissions of regulated pollutants
from a vehicle.
Emission-data component means a vehicle component that is tested
for certification. This includes vehicle components tested to establish
deterioration factors.
Emission-data vehicle means a vehicle (or vehicle component) that
is tested for certification. This includes vehicles tested to establish
deterioration factors.
Emission-related component has the meaning given in 40 CFR part
1068, appendix A.
Emission-related maintenance means maintenance that substantially
affects emissions or is likely to substantially affect emission
deterioration.
Excluded means relating to vehicles that are not subject to some or
all of the requirements of this part as follows:
(1) A vehicle that has been determined not to be a ``motor
vehicle'' is excluded from this part.
(2) Certain vehicles are excluded from the requirements of this
part under Sec. 1037.5.
(3) Specific regulatory provisions of this part may exclude a
vehicle generally subject to this part from one or more specific
standards or requirements of this part.
Exempted has the meaning given in 40 CFR 1068.30. Note that
exempted vehicles are not considered to be excluded.
Extended idle means tractor idle operation during which the engine
is operating to power accessories for a sleeper compartment or other
passenger compartment. Although the vehicle is generally parked during
extended idle, the term ``parked idle'' generally refers to something
different than extended idle.
Family emission limit (FEL) means an emission level declared by the
manufacturer to serve in place of an otherwise applicable emission
standard under the ABT program in subpart H of this part. The family
emission limit must be expressed to the same number of decimal places
as the emission standard it replaces.
Flexible-fuel means relating to an engine designed for operation on
any mixture of two or more different fuels.
Fuel cell electric vehicle means a motor vehicle powered solely by
an electric motor where energy for the motor is supplied by hydrogen
fuel cells. Fuel cell electric vehicles may include energy storage from
the fuel cells or from regenerative braking in a battery.
Fuel system means all components involved in transporting,
metering, and mixing the fuel from the fuel tank to the combustion
chamber(s), including the fuel tank, fuel pump, fuel filters, fuel
lines, carburetor or fuel-injection components, and all fuel-system
vents. It also includes components for controlling evaporative
emissions, such as fuel caps, purge valves, and carbon canisters.
Fuel type means a general category of fuels such as diesel fuel or
natural gas. There can be multiple grades within a single fuel type,
such as high-sulfur or low-sulfur diesel fuel.
Gaseous fuel means a fuel that has a boiling point below 20 [deg]C.
[[Page 36363]]
Glider kit means either of the following:
(1) A new vehicle that is incomplete because it lacks an engine,
transmission, and/or axle(s).
(2) Any other new equipment that is substantially similar to a
complete motor vehicle and is intended to become a complete motor
vehicle with a previously used engine (including a rebuilt or
remanufactured engine). For example, incomplete heavy-duty tractor
assemblies that are produced on the same assembly lines as complete
tractors and that are made available to secondary vehicle manufacturers
to complete assembly by installing used/remanufactured engines,
transmissions and axles are glider kits.
Glider vehicle means a new motor vehicle produced from a glider
kit, or otherwise produced as a new motor vehicle with a with a used/
remanufactured engine.
Good engineering judgment has the meaning given in 40 CFR 1068.30.
See 40 CFR 1068.5 for the administrative process we use to evaluate
good engineering judgment.
Gross combination weight rating (GCWR) means the value specified by
the vehicle manufacturer as the maximum weight of a loaded vehicle and
trailer, consistent with good engineering judgment. For example,
compliance with SAE J2807 is generally considered to be consistent with
good engineering judgment, especially for Class 3 and smaller vehicles.
Gross vehicle weight rating (GVWR) means the value specified by the
vehicle manufacturer as the maximum design loaded weight of a single
vehicle, consistent with good engineering judgment.
Heavy-duty engine means any engine used for (or for which the
engine manufacturer could reasonably expect to be used for) motive
power in a heavy-duty vehicle.
Heavy-duty vehicle means any motor vehicle that has a GVWR above
8,500 pounds. An incomplete vehicle is also a heavy-duty vehicle if it
has a curb weight above 6,000 pounds or a basic vehicle frontal area
greater than 45 square feet.
Hybrid has the meaning given in 40 CFR 1036.801. Note that a hybrid
vehicle is a vehicle with a hybrid engine or other hybrid powertrain.
This includes plug-in hybrid electric vehicles.
Hydrocarbon (HC) means the hydrocarbon group on which the emission
standards are based for each fuel type. For alcohol-fueled vehicles, HC
means nonmethane hydrocarbon equivalent (NMHCE) for exhaust emissions
and total hydrocarbon equivalent (THCE) for evaporative emissions. For
all other vehicles, HC means nonmethane hydrocarbon (NMHC) for exhaust
emissions and total hydrocarbon (THC) for evaporative emissions.
Identification number means a unique specification (for example, a
model number/serial number combination) that allows someone to
distinguish a particular vehicle from other similar vehicles.
Incomplete vehicle has the meaning given in the definition of
vehicle in this section.
Light-duty truck has the meaning given in 40 CFR 86.1803-01.
Light-duty vehicle has the meaning given in 40 CFR 86.1803-01.
Low-mileage means relating to a vehicle with stabilized emissions
and represents the undeteriorated emission level. This would generally
involve approximately 4000 miles of operation.
Manufacture means the physical and engineering process of
designing, constructing, and/or assembling a vehicle.
Manufacturer has the meaning given in section 216(1) of the Act. In
general, this term includes any person who manufactures or assembles a
vehicle (including an incomplete vehicle) for sale in the United States
or otherwise introduces a new motor vehicle into commerce in the United
States. This includes importers who import vehicles for resale,
entities that manufacture glider kits, and entities that assemble
glider vehicles.
Medium-duty passenger vehicle (MDPV) has the meaning given in 40
CFR 86.1803.
Model year means one of the following for compliance with this
part. Note that manufacturers may have other model year designations
for the same vehicle for compliance with other requirements or for
other purposes:
(1) For vehicles with a date of manufacture on or after January 1,
2021, model year means the manufacturer's annual new model production
period based on the vehicle's date of manufacture, where the model year
is the calendar year corresponding to the date of manufacture, except
as follows:
(i) The vehicle's model year may be designated as the year before
the calendar year corresponding to the date of manufacture if the
engine's model year is also from an earlier year. You may ask us to
extend your prior model year certificate to include such vehicles. Note
that Sec. 1037.601(a)(2) limits the extent to which vehicle
manufacturers may install engines built in earlier calendar years.
(ii) The vehicle's model year may be designated as the year after
the calendar year corresponding to the vehicle's date of manufacture.
For example, a manufacturer may produce a new vehicle by installing the
engine in December 2023 and designating it as a model year 2024
vehicle.
(2) For Phase 1 vehicles with a date of manufacture before January
1, 2021, model year means the manufacturer's annual new model
production period, except as restricted under this definition and 40
CFR part 85, subpart X. It must include January 1 of the calendar year
for which the model year is named, may not begin before January 2 of
the previous calendar year, and it must end by December 31 of the named
calendar year. The model year may be set to match the calendar year
corresponding to the date of manufacture.
(i) The manufacturer who holds the certificate of conformity for
the vehicle must assign the model year based on the date when its
manufacturing operations are completed relative to its annual model
year period. In unusual circumstances where completion of your assembly
is delayed, we may allow you to assign a model year one year earlier,
provided it does not affect which regulatory requirements will apply.
(ii) Unless a vehicle is being shipped to a secondary vehicle
manufacturer that will hold the certificate of conformity, the model
year must be assigned prior to introduction of the vehicle into U.S.
commerce. The certifying manufacturer must redesignate the model year
if it does not complete its manufacturing operations within the
originally identified model year. A vehicle introduced into U.S.
commerce without a model year is deemed to have a model year equal to
the calendar year of its introduction into U.S. commerce unless the
certifying manufacturer assigns a later date.
Motor vehicle has the meaning given in 40 CFR 85.1703.
New motor vehicle has the meaning given in the Act. It generally
means a motor vehicle meeting the criteria of either paragraph (1) or
(2) of this definition. New motor vehicles may be complete or
incomplete.
(1) A motor vehicle for which the ultimate purchaser has never
received the equitable or legal title is a new motor vehicle. This kind
of vehicle might commonly be thought of as ``brand new'' although a new
motor vehicle may include previously used parts. For example, vehicles
commonly known as ``glider kits,'' ``glider vehicles,'' or ``gliders''
are new motor vehicles. Under this definition, the vehicle is new from
[[Page 36364]]
the time it is produced until the ultimate purchaser receives the title
or places it into service, whichever comes first.
(2) An imported heavy-duty motor vehicle originally produced after
the 1969 model year is a new motor vehicle.
Noncompliant vehicle means a vehicle that was originally covered by
a certificate of conformity, but is not in the certified configuration
or otherwise does not comply with the conditions of the certificate.
Nonconforming vehicle means a vehicle not covered by a certificate
of conformity that would otherwise be subject to emission standards.
Nonmethane hydrocarbon (NMHC) means the sum of all hydrocarbon
species except methane, as measured according to 40 CFR part 1065.
Nonmethane hydrocarbon equivalent (NMHCE) has the meaning given in
40 CFR 1065.1001.
Official emission result means the measured emission rate for an
emission-data vehicle on a given duty cycle before the application of
any required deterioration factor, but after the applicability of
regeneration adjustment factors.
Owners manual means a document or collection of documents prepared
by the vehicle manufacturer for the owners or operators to describe
appropriate vehicle maintenance, applicable warranties, and any other
information related to operating or keeping the vehicle. The owners
manual is typically provided to the ultimate purchaser at the time of
sale. The owners manual may be in paper or electronic format.
Oxides of nitrogen has the meaning given in 40 CFR 1065.1001.
Particulate trap means a filtering device that is designed to
physically trap all particulate matter above a certain size.
Percent (%) has the meaning given in 40 CFR 1065.1001. Note that
this means percentages identified in this part are assumed to be
infinitely precise without regard to the number of significant figures.
For example, one percent of 1,493 is 14.93.
Petroleum means gasoline or diesel fuel or other fuels normally
derived from crude oil. This does not include methane or liquefied
petroleum gas.
Placed into service means put into initial use for its intended
purpose, excluding incidental use by the manufacturer or a dealer.
Plug-in hybrid electric vehicle means a hybrid vehicle that has the
capability to charge one or more batteries from an external source of
electricity while the vehicle is parked.
Preliminary approval means approval granted by an authorized EPA
representative prior to submission of an application for certification,
consistent with the provisions of Sec. 1037.210.
Rechargeable Energy Storage System (RESS) has the meaning given in
40 CFR 1065.1001.
Relating to as used in this section means relating to something in
a specific, direct manner. This expression is used in this section only
to define terms as adjectives and not to broaden the meaning of the
terms.
Revoke has the meaning given in 40 CFR 1068.30.
Round has the meaning given in 40 CFR 1065.1001.
Scheduled maintenance means adjusting, repairing, removing,
disassembling, cleaning, or replacing components or systems
periodically to keep a part or system from failing, malfunctioning, or
wearing prematurely. It also may mean actions you expect are necessary
to correct an overt indication of failure or malfunction for which
periodic maintenance is not appropriate.
Secondary vehicle manufacturer anyone that produces a vehicle by
modifying a complete vehicle or completing the assembly of a partially
complete vehicle. For the purpose of this definition, ``modifying''
generally does not include making changes that do not remove a vehicle
from its original certified configuration. However, custom sleeper
modifications and alternative fuel conversions that change actual
vehicle aerodynamics are considered to be modifications, even if they
are permitted without recertification. This definition applies whether
the production involves a complete or partially complete vehicle and
whether the vehicle was previously certified to emission standards or
not. Manufacturers controlled by the manufacturer of the base vehicle
(or by an entity that also controls the manufacturer of the base
vehicle) are not secondary vehicle manufacturers; rather, both entities
are considered to be one manufacturer for purposes of this part.
Spark-ignition has the meaning given in Sec. 1037.101.
Suspend has the meaning given in 40 CFR 1068.30.
Test sample means the collection of vehicles or components selected
from the population of a vehicle family for emission testing. This may
include testing for certification, production-line testing, or in-use
testing.
Test vehicle means a vehicle in a test sample.
Test weight means the vehicle weight used or represented during
testing.
Total hydrocarbon has the meaning given in 40 CFR 1065.1001. This
generally means the combined mass of organic compounds measured by the
specified procedure for measuring total hydrocarbon, expressed as a
hydrocarbon with an atomic hydrogen-to-carbon ratio of 1.85:1.
Total hydrocarbon equivalent has the meaning given in 40 CFR
1065.1001. This generally means the sum of the carbon mass
contributions of non-oxygenated hydrocarbon, alcohols and aldehydes, or
other organic compounds that are measured separately as contained in a
gas sample, expressed as exhaust hydrocarbon from petroleum-fueled
vehicles. The atomic hydrogen-to-carbon ratio of the equivalent
hydrocarbon is 1.85:1.
Tractor means a truck designed primarily for drawing other motor
vehicles and not so constructed as to carry a load other than a part of
the weight of the vehicle and the load so drawn. This includes most
heavy-duty vehicles specifically designed for the primary purpose of
pulling trailers, but does not include vehicles designed to carry other
loads. For purposes of this definition ``other loads'' would not
include loads carried in the cab, sleeper compartment, or toolboxes.
Examples of vehicles that are similar to tractors but that are not
tractors under this part include dromedary tractors, automobile
haulers, straight trucks with trailers hitches, and tow trucks.
Ultimate purchaser means, with respect to any new vehicle, the first
person who in good faith purchases such new vehicle for purposes other
than resale.
United States has the meaning given in 40 CFR 1068.30.
Upcoming model year means for a vehicle family the model year after
the one currently in production.
U.S.-directed production volume means the number of vehicle units,
subject to the requirements of this part, produced by a manufacturer
for which the manufacturer has a reasonable assurance that sale was or
will be made to ultimate purchasers in the United States.
Useful life means the period during which a vehicle is required to
comply with all applicable emission standards.
Vehicle means equipment intended for use on highways that meets at
least one of the criteria of paragraph (1) of this definition, as
follows:
(1) The following equipment are vehicles:
(i) A piece of equipment that is intended for self-propelled use on
highways becomes a vehicle when it
[[Page 36365]]
includes at least an engine, a transmission, and a frame. (Note: For
purposes of this definition, any electrical, mechanical, and/or
hydraulic devices attached to engines for the purpose of powering
wheels are considered to be transmissions.)
(ii) A piece of equipment that is intended for self-propelled use
on highways becomes a vehicle when it includes a passenger compartment
attached to a frame with one or more axles.
(2) Vehicles may be complete or incomplete vehicles as follows:
(i) A complete vehicle is a functioning vehicle that has the
primary load carrying device or container (or equivalent equipment)
attached when it is first sold as a vehicle. Examples of equivalent
equipment would include fifth wheel trailer hitches, firefighting
equipment, and utility booms.
(ii) An incomplete vehicle is a vehicle that is not a complete
vehicle. Incomplete vehicles may also be cab-complete vehicles. This
may include vehicles sold to secondary vehicle manufacturers.
(iii) You may ask us to allow you to certify a vehicle as
incomplete if you manufacture the engines and sell the unassembled
chassis components, as long as you do not produce and sell the body
components necessary to complete the vehicle.
Vehicle configuration means a unique combination of vehicle
hardware and calibration (related to measured or modeled emissions)
within a vehicle family. Vehicles with hardware or software
differences, but that have no hardware or software differences related
to measured or modeled emissions may be included in the same vehicle
configuration. Vehicles within a vehicle configuration differ only with
respect to normal production variability or factors unrelated to
measured or modeled emissions.
Vehicle family has the meaning given in Sec. 1037.230.
Void has the meaning given in 40 CFR 1068.30.
Volatile liquid fuel means any fuel other than diesel or biodiesel
that is a liquid at atmospheric pressure and has a Reid Vapor Pressure
higher than 2.0 pounds per square inch.
We (us, our) means the Administrator of the Environmental
Protection Agency and any authorized representatives.
0
148. Amend Sec. 1037.805 by removing ``CO2DEF'' and ``CO2PTO'' from
table 4 to paragraph (d) and revise paragraph (e). The revision reads
as follows:
Sec. 1037.805 Symbols, abbreviations, and acronyms.
* * * * *
(e) Other acronyms and abbreviations. This part uses the following
additional abbreviations and acronyms:
Table 5 to Paragraph (e) of Sec. 1037.805--Other Acronyms and
Abbreviations
------------------------------------------------------------------------
Acronym Meaning
------------------------------------------------------------------------
AECD......................... auxiliary emission control device.
AES.......................... automatic engine shutdown.
APU.......................... auxiliary power unit.
CD........................... charge-depleting.
CFR.......................... Code of Federal Regulations.
CITT......................... curb idle transmission torque.
CS........................... charge-sustaining.
DOT.......................... Department of Transportation.
EPA.......................... Environmental Protection Agency.
FEL.......................... Family Emission Limit.
GAWR......................... gross axle weight rating.
GCWR......................... gross combination weight rating.
GVWR......................... gross vehicle weight rating.
HVAC......................... heating, ventilating, and air
conditioning.
ISO.......................... International Organization for
Standardization.
NARA......................... National Archives and Records
Administration.
NHTSA........................ National Highway Traffic Safety
Administration.
RESS......................... rechargeable energy storage system.
SAE.......................... SAE International.
SEE.......................... standard error of the estimate.
SKU.......................... stock-keeping unit.
U.S.C........................ United States Code.
------------------------------------------------------------------------
* * * * *
Sec. 1037.810 [Removed]
0
149. Remove Sec. 1037.810.
Sec. 1037.825 [Amended]
0
150. Amend Sec. 1037.825 by removing and reserving paragraph (e)(1)(i)
and removing paragraph (e)(1)(iv).
Appendices A Through E to Part 1037 [Removed]
0
151. Remove appendices A through E to part 1037.
PART 1039--CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD
COMPRESSION-IGNITION ENGINES
0
152. The authority citation for part 1039 continues to read as follows:
Authority: 42 U.S.C. 7401-7671q.
0
153. Amend Sec. 1039.699 by revising paragraphs (a) and (n) to read as
follows:
Sec. 1039.699 Emission standards and certification requirements for
auxiliary power units for highway tractors.
(a) This section describes emission standards and certification
requirements for auxiliary power units (APU) installed on highway
tractors subject to standards under 40 CFR 1037.102 starting in model
year 2024.
* * * * *
(n) If a highway tractor manufacturer violates 40 CFR 1037.102 by
installing an APU from you that is not properly certified and labeled,
you are presumed to have caused the violation (see 40 CFR 1068.101(c)).
[FR Doc. 2025-14572 Filed 7-31-25; 8:45 am]
BILLING CODE 6560-50-P