[Federal Register Volume 85, Number 93 (Wednesday, May 13, 2020)]
[Proposed Rules]
[Pages 28564-28586]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-07202]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 86 and 600

[EPA-HQ-OAR-2016-0604; FRL-10007-47-OAR]
RIN 2060-AT21


Vehicle Test Procedure Adjustments for Tier 3 Certification Test 
Fuel

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to make 
adjustments to certain laboratory tailpipe emission testing procedures 
for automobiles, light trucks, and heavy-duty pickup trucks and vans as 
the result of a test fuel change that was finalized as a part of EPA's 
2014 Tier 3 vehicle emissions rule. In that rule, EPA changed its 
laboratory test fuel to be more similar to typical gasoline currently 
in use. In the Tier 3 Final Rulemaking, EPA required vehicle 
manufacturers to perform greenhouse gas (GHG) and CAFE fuel economy 
testing on the new Tier 3 test fuel, beginning for model year 2020 and 
later vehicles. Changes to the fuel used for emissions testing can 
result in a change in emission results on the tests. When we adopted 
the Tier 3 test fuel, we indicated that we intended to undertake 
rulemaking to re-align test results from GHG and CAFE fuel economy 
testing on the new Tier 3 test fuel so they are consistent with test 
results from testing on the original Tier 2 test fuel, in order to 
avoid an effective change in the stringency of the GHG and CAFE 
standards. Specifically, EPA is now proposing adjustment factors to 
apply to both vehicle GHG and fuel economy test results for the GHG and 
CAFE programs and the Fuel Economy and Environment Label. In addition, 
we propose that the shift to required use of the new fuel for all 
vehicle testing be phased in through Model Year 2024, but required in 
Model Year 2025. Because the purpose of the rule is simply to realign 
testing results in response to the test fuel change, there would be no 
significant costs associated with the proposed action.

DATES: 
    Comments: Comments must be received on or before August 11, 2020.
    Public Hearing: If anyone contacts us requesting a public hearing 
on or before May 20, 2020, we will hold a hearing and will publish 
additional information about the hearing in a subsequent Federal 
Register document.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2016-0604, at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. The EPA may publish any 
comment received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the 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). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Tad Wysor, Office of Transportation 
and Air Quality, Assessment and Standards Division, Environmental 
Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; 
telephone number: (734) 214-4332; email address: [email protected].

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. General Information
    A. Does this action apply to me?
    B. What action is the Agency taking?
    C. What is the Agency's authority for taking this action?
    D. What are the incremental costs and benefits of this action?
II. Background and Purpose of the Proposed Test Procedure 
Adjustments
III. Summary of EPA Vehicle Testing Program and Summary of Test 
Results
    A. Summary of the EPA Test Program and Technical Report
    B. Summary of EPA Test Results
IV. Proposed Test Procedure Adjustment Factors
    A. CO2 Adjustment Factor and Approach to Other GHG 
Exhaust Standards
    1. Methane and Nitrous Oxide Emissions Compliance
    B. Fuel Economy (CAFE) Adjustment Factor
    1. Analysis of Data and Development of the Proposed Fuel Economy 
Equation
    2. Proposed Fuel Economy Adjustment Factor
V. Proposed Implementation Schedule
VI. Projected Impacts
VII. Implications of Proposed Adjustments on the Fuel Economy and 
Environment Label
    A. Background
    B. City and Highway Fuel Economy Estimates Displayed on the 
Label
    C. CO2 Performance Estimates Displayed on the Label
    D. Litmus Test
VIII. Statutory Authority and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)

[[Page 28565]]

    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)
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. General Information

A. Does this action apply to me?

    This proposed action would affect companies that manufacture or 
sell new gasoline fueled light-duty vehicles, light-duty trucks, 
medium-duty passenger vehicles, or heavy-duty vehicles up to 14,000 
pounds GVWR, as defined under EPA's CAA regulations,\1\ and passenger 
automobiles (passenger cars), non-passenger automobiles (light trucks), 
and heavy-duty pickup trucks and vans as defined under National Highway 
Traffic Safety Administration's (NHTSA's) Corporate Average Fuel 
Economy (CAFE) regulations.\2\ Regulated categories and entities 
include the following:
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    \1\ ``Light-duty vehicle,'' ``light-duty truck,'' ``medium-duty 
passenger vehicle,'' and ``heavy-duty vehicle'' are defined in 40 
CFR 86.1803-01.
    \2\ ``Passenger automobile'' and ``non-passenger automobile'' 
are defined in 49 CFR parts 523.4 and 523.5, respectively. ``Heavy-
duty pickup trucks and vans'' are defined in 49 CFR part 523.7.

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                                                         Examples of
          Category               NAICS codes \A\         potentially
                                                     regulated entities
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Industry....................  336111, 336112......  Motor Vehicle
                                                     Manufacturers.
                              811111, 811112,       Commercial Importers
                               811198, 423110.       of Vehicles and
                                                     Vehicle Components.
                              335312, 811198......  Alternative Fuel
                                                     Vehicle Converters.
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\A\ North American Industry Classification System (NAICS)

    This list is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. 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.

B. What action is the Agency taking?

    EPA is proposing adjustments to certain laboratory emission testing 
procedures for gasoline fueled light-duty vehicles, light-duty trucks, 
and medium-duty passenger vehicles, and some gasoline fueled heavy-duty 
vehicles,\3\ and provisions for the implementation of these proposed 
adjustments. As a part of EPA's 2014 Tier 3 vehicle emissions rule, 
which applies to non-GHG emissions, EPA changed the laboratory gasoline 
test fuel to be more similar to typical fuels currently in use (79 FR 
23414, 23531, April 28, 2014). In the absence of the action proposed in 
this notice, this change in test fuel would apply to vehicles tested 
for compliance with the GHG and CAFE standards for Model Year (MY) 2020 
and later. Because testing on the new test fuel results in slightly 
different CO2 emissions measurements and fuel economy 
results than does testing on the current test fuel, rulemaking action 
is necessary to re-align test results from GHG and CAFE fuel economy 
testing on the new Tier 3 test fuel so they are consistent with test 
results from testing on the original Tier 2 test fuel, in order to 
avoid a change in the stringency of the GHG and CAFE standards.\4\ In 
addition, as described in detail in Section VII below, EPA is proposing 
to re-align test results from fuel economy testing on the new Tier 3 
test fuel such that the values on the Fuel Economy and Environment 
Label (i.e., the window sticker on new cars and light trucks) remain 
consistent with those generated under the current labeling program. The 
proposed action would also avoid unnecessary vehicle testing burdens as 
auto manufacturers transition to the Tier 3 E10 test fuel for GHG and 
fuel economy testing.
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    \3\ Specifically, vehicles subject to standards under 40 CFR 
part 86, subpart S.
    \4\ In Section IV below, we describe how in the absence of the 
proposed adjustments, the certification test fuel change would 
result in slightly lower CO2 emissions (due to the 
reduced fuel carbon content) and slightly lower fuel economy results 
(due to the overall reduction in fuel energy content due to 
differences in several fuel properties).
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    The regulatory changes that EPA is proposing in this notice would 
accomplish these objectives. Specifically, the proposed adjustments to 
vehicle testing results would avoid changes in the stringency of the 
GHG and CAFE standards as a result of the test fuel transition. Also, 
EPA is proposing to reduce the transitional testing burden on 
manufacturers in three steps, as follows: (1) By delaying the 
requirements to test with Tier 3 fuel for an additional model year, 
from MY 2020 until MY 2021); (2) by allowing optional certification on 
either fuel for model years 2021 and 2022, and allowing manufacturers 
that previously tested certification vehicles for compliance with the 
GHG and CAFE standards to ``carry over'' their existing data; and (3) 
by allowing carryover data for model years 2023 and 2024, but requiring 
new certification testing (for new models not eligible to use carryover 
data) to be done on Tier 3 fuel. Thus, testing of all vehicles on Tier 
3 certification test fuel would not be required until model year 2025. 
See Section V below for more discussion of this proposed phasing-in of 
the new testing requirements. Note that this proposed phase-in schedule 
for the use of Tier 3 fuel is for certification testing to GHG and CAFE 
standards only. All certification testing for non-GHG pollutants must 
continue to be done as required by the Tier 3 rule, using Tier 3 fuel 
as of MY 2020 for LDVs, LDTs, and MDPVs and as of MY 2022 for heavy-
duty pickup trucks and vans.

C. What is the Agency's authority for taking this action?

    Statutory authority for promulgating test procedures relating to 
fuel economy is found in 49 U.S.C. 32901 et seq. That authority 
originated in Title V of the Energy Policy and Conservation Act (Pub. 
L. 94-163, December 22, 1975), section 504(d)(1), and has been 
partially amended a few times, including in Title VII of the Energy 
Policy Act (Pub. L. 109-58, August 8, 2005) and Title I of the Energy 
Independence and Security Act (Pub. L. 110-140, December 19, 2007).
    Statutory authority for promulgating test procedures related to 
EPA's greenhouse gas standards is found in section 206 of the Clean Air 
Act (CAA), which governs EPA's issuances of certificates of conformity. 
Under section 203 of the CAA, sales of vehicles are prohibited unless 
the vehicle is covered by a certificate of conformity.

[[Page 28566]]

D. What are the incremental costs and benefits of this action?

    As discussed in Section II below, this proposed action is designed 
to ensure that the changes in vehicle test fuel characteristics 
occurring under existing regulations do not affect the stringency of 
the current GHG and fuel economy standards or unnecessarily add to 
manufacturer testing burdens. As a result, under our understanding of 
GHG and CAFE stringency, this proposed action by design should not on 
average result in any significant changes in the emissions or fuel 
consumption benefits originally projected for the GHG or CAFE programs, 
nor any changes in the projected technology costs of the standards to 
manufacturers.
    As we discuss in Section IV below, we derived the proposed test 
procedure adjustments on a fleetwide average basis. It is possible that 
vehicle manufacturers may find that for some individual vehicle models 
the proposed adjustments result in slightly different certification 
CO2 emissions or fuel economy calculations in one direction 
or the other. Overall, however, especially in light of the fleetwide 
averaging of the standards, we believe that the proposed adjustment 
factors would result in no significant net changes in certification 
results for manufacturers. We request comment on this conclusion, 
including any data or information indicating that the proposed fleet-
wide average approach would be problematic for any individual 
manufacturer's fleet.
    Regarding the additional certification vehicle testing that the 
transition from Tier 2 to Tier 3 test fuel now underway will 
temporarily require, we discuss in Section V below a proposed 
implementation schedule for the transition to required use of Tier 3 
test fuel (with the associated test procedure adjustments proposed 
here). We believe that the proposed phased implementation schedule will 
minimize any potential disruption of any manufacturer's current testing 
plans.\5\ Because the purpose of this rule is to align certification 
results before and after the transition in test fuels, the proposed 
gradual implementation, including the proposed delay until MY 2021 for 
the required use of Tier 3 fuel, should have no impact on the projected 
benefits and costs of the GHG and CAFE programs.\6\
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    \5\ See EPA Memorandum to Docket EPA-HQ-OAR-2016-0604: ``Listing 
of Technical Consultation Meetings between EPA Staff and Automobile 
Industry Technical Representatives Supporting the Vehicle Test 
Procedure Adjustments for Tier 3 Certification Test Fuel, NPRM.'' 
Among other topics, these meetings included discussions of 
manufacturer fuel economy test scheduling.
    \6\ See EPA Memorandum to Docket EPA-HQ-OAR-2016-0604: ``EPA/
OTAQ--Estimated Cost Savings from Required Certification Test Fuel 
Related Adjustments,'' estimating that the industry-wide savings 
once EPA finalizes these proposed certification fuel adjustments 
will likely be well under $2 million per year.
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II. Background and Purpose of the Proposed Test Procedure Adjustments

    The joint light-duty (LD) greenhouse gas (GHG) and fuel economy 
(FE) rules adopted by EPA and NHTSA (77 FR 62624, October 15, 2012) 
required that fuel economy and GHG emissions performance be measured in 
laboratory testing of vehicles using the long-standing regulatory 
gasoline and diesel test fuels.\7\ The Tier 2 gasoline test fuel that 
has long been used for fuel economy and GHG testing is significantly 
different from today's market gasoline used by consumers. Over time, 
refiners have changed the composition and characteristics of market 
gasoline. Since the last time EPA changed our gasoline test fuel in the 
1980s, market gasoline has become more distinct from Tier 2 test fuel, 
most notably in that Tier 2 fuel contains no ethanol (``E0 fuel'') and 
it has higher levels of aromatic compounds (or ``aromatics''). However, 
EPA did not pursue any changes to test fuel properties in the 2012 
rule.
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    \7\ Similarly, the 2016 heavy-duty (HD) ``Phase 2'' GHG and fuel 
consumption rules, as they apply to large pickup trucks and vans, 
did not take action to change the gasoline test fuel, deferring to 
the test fuel change specified for these vehicles in the earlier 
Tier 3 rule discussed below. (The HD Phase 2 final rule is at 81 FR 
73740, October 25, 2016). Note that the HD Phase 2 rule separately 
addressed test fuels for certifying heavy-duty gasoline engines.
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    In 2014, EPA's Tier 3 final rule focused on reductions in non-GHG 
emissions (79 FR 23414, April 28, 2014).\8\ As a part of the Tier 3 
rule, and in order to ensure the Tier 3 rule's reductions in non-GHG 
emissions were achieved, EPA acted to reduce the key differences in the 
properties between today's in-use fuel and the regulatory test fuel. In 
that rule, EPA introduced new test fuel specifications that are much 
more similar to the properties of typical fuels commercially available 
today, which on average contain about 10 percent ethanol (called ``E10 
fuel'') and lower levels of aromatics than did the earlier E0 test 
fuel. Both of these changes in fuel composition affect the amount of 
carbon and energy per unit of volume of the fuel. These differences 
result in small, but not insignificant, changes in the tailpipe 
emissions of CO2 and in the fuel economy values that are 
calculated based on those CO2 emissions,\9\ as the EPA 
vehicle test program (Section III below) clearly demonstrates.
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    \8\ The Tier 3 rule applied to LDVs, LDTs, and MDPVs, as well as 
to large pickup trucks and vans (i.e., heavy-duty Class 2b and 3 
vehicles), including establishing implementation schedules for 
implementing the change in test fuel for the light-duty and heavy-
duty vehicle categories.
    \9\ The change in test fuel that EPA established in the 2014 
Tier 3 rule phased in the required use of Tier 3 E10 test fuel for 
testing for the new Tier 3 ``criteria emissions'' standards over 
several years, through MY 2019 (LDVs) and MY 2021 (HDVs).
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    As discussed in Section III, EPA estimates that the impact on 
CO2 emissions is a 1.6% difference, and thus without the 
test procedure adjustment proposed in this notice, a change from the 
Tier 2 gasoline certification fuel to the Tier 3 gasoline certification 
fuel would reduce the stringency of the EPA CO2 standards by 
1.6%. Thus, this action is predicated on a view of GHG and CAFE 
stringency as relating to vehicle efficiency rather than tailpipe 
emissions in a market representative fuel mix. EPA requests comment on 
whether the Agency should consider a regulatory approach where we 
require the use of Tier 3 gasoline certification fuel without any test 
procedure adjustment for CO2. If the Agency were to consider 
such an approach, EPA also requests comment as to whether EPA would 
need to complete additional analysis, likely in the form of a 
Supplemental Notice of Proposed Rulemaking (SNPRM), or whether EPA 
could finalize a change in the gasoline certification fuel without any 
CO2 adjustment factor and without issuing a SNPRM.
    Instead of addressing the changes in test results caused by the 
change in test fuel by using the Administrator's authority to change 
the stringency of the standards under CAA 202(a), this rule proposes to 
maintain the existing stringency and use the Administrator's separate 
authority to modify the emission testing procedures under CAA 206(d). 
Under this authority, we have developed and are proposing to establish 
the numerical factors that will adjust emission test results and fuel 
economy calculations such that the test fuel changes do not on average 
increase or reduce the stringency of the existing CO2 and 
fuel economy standards.
    Beyond the CO2 and fuel economy adjustment factors that 
we are proposing in order to maintain the stringency of the current 
standards, an additional requirement comes into play with respect to 
fuel economy compliance testing. When EPA makes changes to the test 
procedures, including changes to test fuel, that apply to testing for 
fuel economy compliance, the statutory provisions governing the CAFE 
program

[[Page 28567]]

(see Section I.C above) require EPA to use ``procedures that give 
comparable results'' to earlier procedures (see 49 U.S.C. 32904(c)):
    It is important to distinguish that for testing for CO2 
emissions compliance under the Clean Air Act, the statute allows, but 
does not require, similar adjustments back to 1975 test procedures, 
including for changes in test fuel properties. Based upon our view of 
stringency means, we do not see any value to making such an additional 
adjustment for CO2 and instead are proposing a simple 
adjustment to CO2 certification emission test results.
    In the Tier 3 rule (at 79 FR 23531), EPA required refiners to make 
changes to market gasoline that were necessary to enable the stringent 
new standards for vehicle emissions of criteria pollutants and their 
precursors. In that same rule, EPA adopted changes to certification 
test fuel that would better represent in-use gasoline, including the 
new in-use gasoline changes.\10\ EPA recognized that these changes to 
the test fuel would likely have some effect on certification testing 
results for the GHG and CAFE standards that had been adopted a few 
years before. However, EPA lacked sufficient data at that time to 
determine the magnitude of any such effect. Accordingly, EPA committed 
to undertaking a study of the effect of the change in test fuel, and, 
if appropriate, to propose test procedure adjustments. Our intent was 
to ensure that the stringency of the GHG and CAFE programs would not be 
affected by the change in test fuel.
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    \10\ For example, market gasoline has gradually evolved over the 
past two decades from largely zero ethanol and higher aromatics 
(around 31%) to nearly universal 10% ethanol fuel and lower 
aromatics (about 23%), qualities that are represented in the current 
Tier 3 certification fuel. The Tier 3 rule (2014) also reduced fuel 
sulfur content, which is important for catalytic converter operation 
and criteria emissions control, but which does not affect 
CO2 or fuel economy and is not relevant to this proposed 
action.
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    These anticipated test procedure adjustments were to center around 
adjustments to the measured CO2 results and the fuel economy 
calculations used to quantify vehicle GHG emissions and fuel economy 
performance. During the Tier 3 rulemaking, EPA and manufacturers 
recognized that insufficient GHG emission and fuel economy data existed 
at the time to appropriately quantify the impact of the new test fuel, 
especially on more advanced vehicle technologies that have recently 
been introduced in the light-duty fleet. Thus, as mentioned above, we 
committed to conducting a vehicle and fuel testing program to develop 
emissions data on both fuels to support such test procedure 
adjustments. As discussed in Section III below, EPA has now completed 
such a test program.
    Also in the Tier 3 rule we recognized that prior to the 
implementation of any such adjustments and during any phase-in of new 
test fuel requirements, manufacturers might choose to perform parallel 
compliance testing on both fuels (i.e., to perform Tier 3 compliance 
testing on E10 fuel but also continuing to perform GHG and CAFE fuel 
economy testing on E0 fuel during the transition). To reduce this 
potential temporary regulatory burden, EPA put in place several interim 
provisions to provide testing flexibility and reduce the number of 
additional required tests during the transition from the previous Tier 
2 E0 test fuel to the new Tier 3 E10 test fuel.
    In the Tier 3 preamble (79 FR 23533), EPA stated our intention to 
complete a rulemaking establishing a cutoff date after which 
manufacturers would need to perform all compliance testing on Tier 3 
fuel, as well as establishing the related test procedure adjustments, 
in time for MY 2020 certification. EPA also noted in the Tier 3 
preamble that manufacturers suggested various approaches to when and 
how such a requirement might be implemented, including phased 
provisions and revised provisions for carryover of earlier test data. 
Manufacturers also requested that the implementation of the new fuel 
requirement and corresponding test procedure adjustments take into 
account the necessary lead time and the temporary added testing burden 
generally required by the industry during a transition between 
certification test fuels.
    In the sections below, EPA describes the steps we propose to take, 
as we anticipated in the 2014 Tier 3 rule. In Section III, we summarize 
the vehicle testing program that we have now conducted, designed to 
compare measured CO2 emissions and calculated fuel economy 
on both the Tier 2 and Tier 3 test fuels, on vehicles incorporating 
advanced fuel efficiency technologies. We then describe our analyses of 
those data, concluding with our proposed CO2 and fuel 
economy adjustment factors.\11\
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    \11\ Note that because EPA set the Tier 3 ``criteria emissions'' 
standards based on testing on Tier 3 E10 certification test fuel, 
there is no misalignment between those standards as the auto 
industry has transitioned to testing on Tier 3 fuel for Tier 3 
certification, and thus no test procedure adjustments are needed for 
criteria emissions testing.
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    As we discuss in detail in Section IV below, we needed to take two 
separate approaches to arriving at the proposed CO2 and fuel 
economy adjustment factors. The effect of the change in test fuel on 
CO2 is measured directly from the tailpipe emissions. For 
this reason, and as discussed below, we directly used the observed 
change in CO2 emissions between the two fuels from our test 
program as the proposed CO2 adjustment factor, in order to 
baseline stringency more clearly in line with vehicle efficiency.
    In contrast, fuel economy is derived indirectly using a formula 
that converts the measured mass of CO2 (and other carbon 
emissions), in grams per mile, into a volume of gasoline used (miles 
per gallon), incorporating assumed or measured properties for the 
gasoline such as its energy and carbon content, as discussed below.
    Because it relates the carbon content of the liquid fuel with the 
total carbon content of the gaseous emissions, fuel economy calculated 
in this way is often called the ``carbon-balance'' fuel economy. This 
method was devised in the 1970s to be a more practical and more 
accurate representation of the actual fuel economy than could be 
measured directly by attempting to precisely compare volumes of 
gasoline before and after the test.
    An additional analytical step is necessary to convert the 
calculated carbon-balance fuel economy result into ``CAFE'' results, as 
required for CAFE compliance by the EPCA statute (and subsequent 
amendments) referenced in Section I.C above. This additional step is 
needed because test fuel properties have changed over the years. The 
EPCA (and subsequent) statutes require that test results that are to be 
used for CAFE compliance be consistent with results that would have 
been calculated in 1975, when the law was passed.\12\ Because of this, 
in 1986 EPA adopted a modified carbon-balance fuel economy equation 
that was intended to align the calculated fuel economy values on 
average with 1975 test fuel and test conditions.\13\ EPA made this 
change to account for the change in test fuel properties related to the 
phase out of lead from market gasoline. The CAFE equation revised at 
that time remains in effect today. We present that equation and discuss 
it further in Section IV.B.1 below.
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    \12\ 49 U.S.C. 32904(c).
    \13\ FR volume 51, page 37844, October 24, 1986.
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    The CAFE equation combines a term that represents carbon-balance 
fuel economy and a term that compensates for changes in the test fuel's 
volumetric energy density (VED) relative to the baseline fuel. This 
additional factor recognizes that a difference in VED

[[Page 28568]]

between test fuels is the primary driver of differences in fuel economy 
test results. This term in the equation also includes the empirical 
``R'' factor, which EPA introduced in 1986 to reflect the sensitivity 
of fuel economy to a change in fuel energy content and set its value at 
0.6, as discussed further in Section IV.B.1 below.\14\
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    \14\ FR volume 51, page 37844, October 24, 1986.
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    We are proposing an updated CAFE equation for use with Tier 3 test 
fuel. In this proposed new equation, the original R-factor would be 
replaced by a new factor (Ra). In addition to accounting for 
the change in fuel energy content (the role of the original R-factor), 
the new empirically-derived Ra in effect incorporates that 
factor, but also other impacts that may result from the change in test 
fuel (e.g., from the change in aromatics content between Tier 2 and 
Tier 3 fuel). Ra also incorporates any effects due to the 
updated methodologies that we now use to measure fuel properties, as 
discussed in Section IV.B. below. For the purpose of this rule, there 
is no need to separately evaluate these different factors or their 
interactions (including determining a new value for the original fuel 
energy content related ``R-factor''), and we have not done so.
    We have determined Ra empirically such that the CAFE 
calculation from testing using Tier 3 test fuel would on average be 
numerically equivalent to the calculation that would have occurred 
using Tier 2 test fuel and the long-standing value of 0.6 assigned to 
the original R-factor. We are also proposing minor updates to the CAFE 
equation, as discussed in detail in Section IV.B.1 below. This proposed 
factor Ra would serve as the CAFE fuel economy adjustment 
factor for testing on Tier 3 test fuel. Section IV.B below describes 
how we developed the proposed value for Ra, which results in 
adjusted CAFE compliance values that account for all test procedure, 
test condition, and test fuel changes since 1975, including the current 
transition to Tier 3 test fuel. We invite comment on this adjustment, 
and on our approach generally to harmonizing the baseline between GHG 
and CAFE standards.
    Finally, as discussed in Section V below, we are proposing a delay 
in the existing requirement from the Tier 3 program for manufacturers 
to complete their transitions to performing all of their testing on 
Tier 3 E10 test fuel, which we believe would avoid excessive testing 
burden on the automotive industry.

III. Summary of EPA Vehicle Testing Program and Summary of Test Results

A. Summary of the EPA Test Program and Technical Report

    In order to respond to the need for test procedure adjustments due 
to the change to Tier 3 certification fuel, EPA conducted a test 
program at EPA's National Vehicle and Fuel Emissions Laboratory to 
quantify the differences in GHG emissions and fuel economy between Tier 
2 and Tier 3 certification test fuels. This effort required additional 
steps beyond conventional testing methodologies, with a focus on 
reducing test-to-test variability in order to discern relatively small 
emissions effects on the order of 1.5-2 percent. The peer-reviewed 
Technical Report titled ``Tier 3 Certification Fuel Impacts Program'' 
\15\ contains the details of the study design, how we conducted the 
testing, and our analysis of the results. EPA released this report to 
the public in January of 2018.
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    \15\ EPA Technical Report ``Tier 3 Certification Fuel Impacts 
Test Program'' January 2018, EPA-420-R-18-004 (https://www.epa.gov/moves/tier-3-certification-fuel-impacts-test-program). Docket EPA-
HQ-OAR-2016-0604.
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    EPA designed the study to test vehicles that incorporated a variety 
of advanced powertrain technologies that already have a significant and 
increasing presence in the market today and are expected to be among 
the primary technologies applied by manufacturers to meet future GHG 
and fuel economy standards. Our selection of vehicles for the test 
program was designed to address the narrow purpose of this rule: 
Quantifying appropriate CO2 and CAFE adjustments that on 
average would prevent the change in the stringency of those standards 
that would otherwise occur as the certification test fuel changed. We 
note that because it was necessary in this case for EPA to estimate 
test fuel effects into future years, we were not able to base our 
vehicle selection solely on the vehicle fleet as it currently exists. 
In other words, it was critical that the agency select vehicles 
equipped with technologies that represent how the fleet will look in 
the future (rather than how the fleet looks today). We invite comment 
upon this approach.
    To capture the emission and fuel economy effects with the 
technologies that are becoming widespread in the fleet, we concluded 
that it was important to cover a wide range of engine configurations 
and cylinder displacements, and related technologies. We intentionally 
focused on specific technologies that we expect manufacturers to widely 
use in future vehicles, instead of on specific vehicles, for two 
reasons: (1) Fuel effects on GHG emissions and fuel economy relate 
primarily to combustion characteristics of the engine, rather than to 
vehicle characteristics (e.g., mass and aerodynamics); (2) While we are 
reasonably certain that the technologies we selected and tested will 
dominate the light-duty fleet in coming years, the distribution of 
specific vehicles in which they will be used over the 2025 and later 
time period is much more difficult to anticipate. EPA believes that the 
appropriateness of focusing our test vehicle selection on key engine 
and powertrain technologies is further reinforced by the long-standing 
practice by most manufacturers of using a single engine type in several 
different models of passenger cars, cross-overs, SUVs, minivans, and/or 
pick-up trucks.
    Table III-2 below lists the powertrain technologies that EPA 
selected, after a series of technical consultation meetings with the 
Alliance and Global Automakers.\16\ The selected vehicles cover 4-, 6-, 
and 8-cylinder engines, and a wide range of displacements per cylinder 
(ranging from 0.375 to 0.75 liters of displacement per cylinder). In 
addition, EPA's selected engines included both naturally aspirated and 
turbocharged engines and both direct-injection and port-injection fuel 
delivery systems.\17\ Because these engine characteristics largely 
determine the dynamics of fuel combustion, they are closely related to 
emissions and efficiency when test fuel changes. We also included newer 
transmission technologies to reveal any potential effects beyond the 
engine. Several of these engine and transmission technologies are in 
widespread use today, and we expect the others to become more prevalent 
as future GHG, CAFE, and Tier 3 standards take effect.
---------------------------------------------------------------------------

    \16\ See EPA Memorandum to Docket EPA-HQ-OAR-2016-0604: 
``Listing of Technical Consultation Meetings between EPA Staff and 
Automobile Industry Technical Representatives Supporting the Vehicle 
Test Procedure Adjustments for Tier 3 Certification Test Fuel, NPRM. 
Among other topics, these meetings included detailed discussions of 
vehicle selection and test methodology issues for the EPA vehicle 
test program underway at the time.
    \17\ EPA did not include electric hybrid powertrains in the test 
program because the additional test variability caused by 
differences in battery state of charge and engine on/off operation 
would likely confound the small fuel effects.
---------------------------------------------------------------------------

    As illustrated in the 2018 EPA Automotive Trends Report, the use of 
the key technologies incorporated in the EPA test program is growing in 
a wide range of vehicle applications across the industry, at the same 
time that earlier

[[Page 28569]]

competing technologies are generally declining.\18\
---------------------------------------------------------------------------

    \18\ The 2018 EPA Automotive Trends Report describes in detail 
the most recent trends among powertrain technologies, beginning at 
P. 37: https://www.epa.gov/automotive-trends/download-automotive-trends-report#Full%20Report.
---------------------------------------------------------------------------

    We chose eleven vehicles that incorporated one or more of these 
relevant advanced technologies, including the following: Gasoline 
direct injection (GDI) (which enables higher compression ratios for 
improved fuel efficiency and emissions reductions); engine 
turbocharging, (generally in conjunction with smaller, more efficient 
engines, another growing approach to improved fuel efficiency and 
reduced emissions); naturally aspirated high compression engines 
(featuring a high degree of valve timing authority to allow operation 
as Atkinson-Cycle engines when required; cylinder deactivation 
technology (to allow one or more cylinders to be deactivate while the 
vehicle is cruising, reducing fuel consumption and emissions); 
automatic transmissions with higher numbers of gears, as well as 
Continuously Variable Transmissions (CVTs), to allow engines to stay in 
the most efficient engine speed range as much as possible, improving 
fuel use and emissions. The test program also included a large pickup 
truck, a ``Class 2b'' heavy-duty vehicle, to assess whether larger 
gasoline trucks with engine technology that is common today and is 
likely to continue into the future show similar effects to LDVs and 
LDTs.\19\
---------------------------------------------------------------------------

    \19\ As discussed above, EPA regulates Class 2b (and Class 3) 
heavy-duty vehicles, which have gross vehicle weight ratings greater 
than 14,000 pounds, separately from light-duty vehicles, but the 
2014 Tier 3 certification test fuel changes applied to testing for 
both of these vehicle categories.
---------------------------------------------------------------------------

    The use of these technologies has been growing, and we expect them 
to continue to grow. For example, between 2008 and 2018, in the new 
model year fleet:
     Gasoline direct injection (GDI) penetration has grown from 
2% to 51%.
     Gasoline engine turbocharging has grown from 3% to 31%.
     Cylinder deactivation has grown from 7% to 12%.
     8-speed transmissions have grown from 0.2% to 19%.
     Continuously Variable Transmissions (CVTs) have grown from 
6% to 20%.
    The vehicles we selected for the test program were production 
vehicles that had emission levels that were compliant or nearly 
compliant with the Tier 3 emission standards. All of the vehicles we 
tested for this program were certified by the manufacturers to operate 
appropriately on regular grade fuel, to avoid any potential octane 
effects from the test fuel change (i.e., from higher-octane Tier 2 test 
fuel to lower-octane Tier 3 test fuel).
    Some stakeholders have asked EPA to consider using the 
manufacturer-generated test data that they submit to the EPA vehicle 
certification database as an alternative data source for estimating the 
impact of the change in CO2 and fuel economy performance due 
to the test fuel change, rather than the data from the separate EPA 
vehicle test program.\20\ In fact, early in the development of this 
proposed action, EPA considered the potential value of using available 
manufacturer certification data for this purpose of quantifying the 
impact of the test fuel change. However, EPA concluded that the 
manufacturer certification data submitted to EPA could not be used for 
the purpose of the technical analysis needed for this rule. As shown in 
Table III-1 below, EPA recognizes that there are many sources of 
vehicle test-to-test variability, and we have developed methodologies 
to control for these sources of variability for this test program. 
EPA's testing methodologies were informed by our experience with the 
challenges of measuring fuel effects on vehicle emission performance. 
EPA concluded that it is not possible to use manufacturer certification 
data, as submitted to EPA, to quantify the effects of the Tier 3 fuel 
change on CO2 and fuel economy. This is why EPA instead 
designed a targeted, controlled test program for the particular 
purposes of this rule.
---------------------------------------------------------------------------

    \20\ See briefing document provided by the Alliance of 
Automobile Manufacturers for E.O. 12866 meeting May 28, 2019, EPA 
Docket EPA-HQ-OAR-2016-0604.
---------------------------------------------------------------------------

    In performing the testing of the selected vehicles, we took 
additional steps beyond those specified in the existing compliance 
testing regulations in order to reduce test-to-test variability to very 
low levels. This was necessary because we were working to discern very 
small changes in emissions and fuel economy between tests on the two 
fuels, requiring lower test-to-test variability than has been 
historically accepted for such testing, including compliance 
testing.\21\ We accomplished this goal in several ways, in general by 
reducing or eliminating potential sources of variability. These steps 
included completing testing of one vehicle on one fuel in a single work 
week; maintaining the same test site and vehicle driver throughout the 
program across all fuels and vehicles; thorough removal of the previous 
test fuel from the fuel system, with enough driving to allow for the 
engine to adapt to the new fuel properties; maintaining the same number 
and type of test, and the same sequence, during each day of testing; 
and ensuring a fully-charged battery by using a trickle-charger 
overnight, over weekends, and over extended periods between tests. By 
taking these actions like these, we were able to reduce test-to-test 
variability significantly as compared to most routine testing on these 
test cycles.
---------------------------------------------------------------------------

    \21\ For example, EPA historically allows up to a three percent 
difference in fuel economy from test to test when performing 
engineering evaluations. Guidance document VPCD-97-01 for testing 
vehicles with knock sensors highlights this existing variability 
allowance.
---------------------------------------------------------------------------

    Table III-1 lists several of the key features of vehicle testing 
that affect the variability of test results and that we specifically 
incorporated into the EPA vehicle test program. As shown, these 
methodological features are typically not present during manufacturer 
certification testing (nor are necessary for the accuracy required for 
that purpose).

               Table III-1--Test Variables Requiring Control for Accurate Fuel Effects Measurement
----------------------------------------------------------------------------------------------------------------
                                                                                        Available manufacturer
                 Methodological features                       EPA test program           certification data
----------------------------------------------------------------------------------------------------------------
Identical test fuels across all test vehicles...........                        Yes                          No
Appropriate methods for measuring Tier 3 (oxygenated)                           Yes                      Rarely
 test fuel properties...................................
Multiple measurements of test fuel properties across                            Yes                          No
 several labs/samples...................................
Comparative testing done in same test cell (to minimize                         Yes                      Rarely
 impacts from vehicle loading and coast-down simulation,
 etc.)..................................................
Testing using same driver...............................                        Yes                          No
Testing using exact same test vehicle for all testing of                        Yes                      Rarely
 a vehicle model........................................

[[Page 28570]]

 
Careful control of vehicle preparation to reduce                                Yes                          No
 variability (beyond CFR requirements)..................
Statistical assessment of number of test replicates                             Yes                          No
 needed.................................................
Monitoring driver performance metrics for consistency                           Yes                          No
 with comparative tests.................................
Highly controlled sequencing of test types (FTP, HFET,                          Yes                          No
 US06)..................................................
Fuel sequence order switched to avoid vehicle ``learning                        Yes                          No
 bias''.................................................
Repeat of test sequences when necessary for statistical                         Yes                          No
 confidence.............................................
----------------------------------------------------------------------------------------------------------------

    EPA requests comments on ways that manufacturer certification data 
submitted to EPA, or any other data, might be used as an appropriate 
supplemental or alternative source of data for the purpose of 
quantifying the small average impacts on CO2 and fuel 
economy due to the Tier 3 test fuel change. We request that commenters 
include any data or analysis that could mitigate the concerns we 
express above about the use of such data for the purpose of this 
proposed rule
    Table III-2 lists the test vehicles EPA used in this test program 
and the key technologies they incorporated. EPA requests comment on our 
decision to focus our test vehicle selection for this program on 
vehicles with certain engine and powertrain technologies, and on the 
specific technologies we selected (Table III-2). EPA also requests any 
data that would indicate that the fuel economy and/or CO2 
performance of vehicles with other technologies that are currently 
widespread or are likely to be in the near future would vary from the 
consistent patterns seen in the EPA vehicle test program.

  Table III-2--Summary of EPA Vehicle Testing Program & Summary of Test
                   Results: EPA Test Program Vehicles
------------------------------------------------------------------------
                     Vehicle Make/
    Model year           Model             Engine          Technologies
------------------------------------------------------------------------
2014..............  Ram 1500.......  3.6L V6 PFI.......  8 speed
                                                          automatic
                                                          transmission,
                                                          start-stop
                                                          disabled.
2016..............  Acura ILX......  2.4L I4 GDI.......  8 speed DCT
                                                          with a torque
                                                          converter.
2013..............  Nissan Altima..  2.5L I4 PFI.......  CVT.
2016..............  Honda Civic....  1.5L I4 GDI.......  CVT, downsized
                                                          turbocharged
                                                          engine.
2015..............  Ford F150 Eco-   2.7L V6 GDI.......  Downsized
                     Boost.                               turbocharged
                                                          engine, start-
                                                          stop disabled.
2013..............  Chevrolet        2.4L I4 GDI.......  Gasoline direct
                     Malibu                               injection
                     (``Malibu 1'').                      engine.
2016..............  Chevrolet        1.5L I4 GDI.......  Downsized
                     Malibu                               turbocharged
                     (``Malibu 2'').                      engine.
2014..............  Mazda 3........  2.0L I4 GDI.......  High
                                                          compression
                                                          ratio engine.
2014..............  Chevrolet        4.3L V6 GDI.......  Cylinder
                     Silverado 1500.                      deactivation.
2015..............  Volvo S60 T5...  2.0L I4 GDI.......  Downsized
                                                          turbocharged
                                                          engine.
2016..............  Chevrolet        6.0L V8 PFI.......  Class 2b truck.
                     Silverado 2500.
------------------------------------------------------------------------

    We note that the EPA test program and the associated Technical 
Report only evaluated the change in carbon-balance fuel economy between 
the two test fuels, not changes in CAFE calculations. However, these 
data serve as a basis for developing the proposed CAFE fuel economy 
adjustment factor described in Section IV below.

B. Summary of EPA Test Results

    The EPA test program described above generated a set of high-
quality vehicle emissions data, which then also served as inputs to the 
carbon-balance fuel-economy equation, on each of the two fuels of 
interest. The associated Technical Report referenced above includes a 
comprehensive summary and comparison of these data. We refer 
stakeholders interested in a fuller presentation of the entire program 
to the Technical Report.
    The Technical Report, as a comprehensive presentation of EPA test 
program and its results, is independent of this rule and will likely be 
valuable in other contexts. Much of the data collected in the test 
program and presented in the Technical Report is relevant to the 
development of the adjustment factors proposed in this rulemaking, as 
described in Section IV below. However, the report does not present the 
proposed adjustment factors or the analyses leading to them.
    In summary, Figure III-1 shows the average percent change in 
CO2 emissions by vehicle, calculated with respect to the 
Tier 2 fuel (or mathematically: % Difference = (T3-T2)/T2 x 100). The 
results indicate that for the Federal Test Procedure (FTP) and the 
Highway Fuel Economy Test (HFET) cycles, going from Tier 2 fuel to Tier 
3 fuel results in a reduction in CO2 per mile of 1.78 and 
1.02 percent, respectively, corresponding to absolute CO2 
emissions decreases of 6.37 and 2.16 g/mi, respectively.\22\ Vehicles 
which emitted comparatively large amounts of CO2 on Tier 2 
fuel generally showed larger reductions in absolute CO2 
emissions when moving from Tier 2 fuel to Tier 3 fuel. However, these 
vehicles produced similar reductions to the other vehicles in the test 
program when expressed as a percent reduction, indicating a consistent 
effect proportional to the base vehicle performance of the test 
vehicle. In our view, stringency under GHG and CAFE standards relates 
to this base performance, rather than absolute CO2 emissions 
levels. As market representative test fuel mixes become more efficient, 
it becomes comparatively easier for comparatively inefficient vehicles 
to comply with these standards. Under this view of stringency, then, it 
is necessary to realign test results to maintain efficiency controls at 
the vehicle manufacturer level. EPA invites comment on this approach.
---------------------------------------------------------------------------

    \22\ The FTP and HFET are EPA's standard dynamometer driving 
cycles, simulating city and highway driving, respectively.
---------------------------------------------------------------------------

    Similarly, Figure III-2 shows the average percent change in actual 
in carbon-balance fuel economy when moving from Tier 2 to Tier 3 fuels, 
calculated in the same way as the CO2 differences. We used 
the fuel-economy

[[Page 28571]]

values on each fuel calculated from measured CO2 and other 
carbon-containing emissions to generate the actual carbon-balance fuel 
economy, before the final conversion to CAFE compliance values. The 
results indicate that for the FTP and the HFET cycles, the average 
reduction in fuel economy when moving from Tier 2 fuel to Tier 3 fuel 
are 2.29 percent and 2.98 percent, respectively, corresponding to 
average reductions in fuel economy of 0.66 and 1.34 miles per gallon.
[GRAPHIC] [TIFF OMITTED] TP13MY20.002


[[Page 28572]]


[GRAPHIC] [TIFF OMITTED] TP13MY20.003

    The Acura showed a noticeably larger fuel economy difference than 
other vehicles on the highway cycle (HFET). To investigate this 
behavior, we performed a limited number of additional tests of this 
vehicle on both regular grade Tier 3 fuel and premium grade (higher 
octane) Tier 3 fuel. The results showed an unexpected level of fuel 
economy sensitivity to the test fuel's octane rating.\23\ So although 
we present the results for this vehicle here and in the Technical 
Report, we have excluded it from the analysis we used to determine the 
proposed test procedure adjustments in Section IV. Because this vehicle 
is not labeled by the manufacturer as requiring premium fuel, this 
behavior was unexpected on the recommended (lower octane) fuel. We thus 
did not want these results to inappropriately affect the proposed 
adjustments to CO2 and fuel economy.
---------------------------------------------------------------------------

    \23\ Emission certification fuel, including Tier 2 test fuel, 
has historically been high-octane grade as a matter of convenience 
to avoid having to maintain separate octane levels of test fuels for 
different vehicle requirements. Later, with the implementation of 
electronic ignition and knock sensors in the 1990s, it became 
possible for the engine controls to optimize combustion for a number 
of factors including the fuel octane level, with varying effects on 
emissions and fuel economy. Thus, EPA issued guidance to 
manufacturers in 1997 (VPCD-97-01) clarifying that, in order to 
ensure representativeness of FE test results to real-world driving, 
any difference in emissions or FE between high octane and regular 
octane market fuel must be declared if it exceeds a 3% allowance for 
normal test-to-test variability. This requirement did not apply if 
the vehicle was marketed as requiring higher octane fuel. Note that 
under the Tier 3 program, the default test fuel is now regular 
octane, which obviates the situation of undeclared octane impacts 
between certification tests ad in-use driving on market gasoline.
---------------------------------------------------------------------------

IV. Proposed Test Procedure Adjustment Factors

    In this section, we describe how we used relevant data from the EPA 
test program summarized in the previous section to develop the proposed 
test fuel related adjustment factors. We present below the separate 
analyses we conducted to determine these adjustment factors for 
CO2 and for CAFE fuel economy.
    We note that the EPA test program results described in the 
Technical Report and summarized above differ in perspective from our 
development of the proposed adjustment factors discussed in this 
section. The Technical Report described the change in emissions and 
fuel economy with the transition from the current Tier 2 fuel to Tier 3 
fuel, so those comparisons were formed as Tier 3 relative to Tier 2 
fuel. In contrast, this section describes how we used the test program 
results to determine adjustment factors that would maintain the 
stringency of the existing standards when testing is performed on Tier 
3 test fuel. Thus, the comparison in this section is formed as Tier 2 
relative to Tier 3 fuel. Another difference is the ASTM method \24\ 
used to determine the carbon mass fraction of the test fuel for 
calculation of fuel economy. In the Technical Report we used the 
average D5291 result from five laboratories, whereas here we use the 
D3343 method modified for ethanol as appropriate, consistent with the 
proposed regulatory CAFE equation.\25\
---------------------------------------------------------------------------

    \24\ ASTM International (previously known as American Society 
for Testing and Materials).
    \25\ See proposed regulations at 40 CFR 600.113 and memo 
``Distillation adjustment for ethanol blending in Tier 3 and LEVIII 
test fuels'' submitted by Aron Butler to docket EPA-HQ-OAR-2016-
0604.
---------------------------------------------------------------------------

    Most individual vehicle and powertrain combinations will react 
slightly differently to a change in test fuel. As a result, an approach 
to test fuel

[[Page 28573]]

related adjustment that attempted to recognize the unique responses of 
every vehicle would be very complicated and, we believe, difficult to 
implement in a practical manner for manufacturer testing. Therefore, we 
are proposing to derive the adjustments based on average values. Such 
an averaging approach is not new. Historically, when EPA has corrected 
new test results back to the results on a previous test fuel EPA 
required that differing vehicle responses be accounted for on average, 
as discussed in Section II above. We believe this approach continues to 
be sufficient and appropriate for compliance with fleet-average 
requirements for fuel economy and CO2.
    We developed the proposed CO2 and CAFE adjustment 
factors based on the Federal Test Procedure (FTP) and Highway Fuel 
Economy Test (HFET) results from the EPA test program, as described 
below for each of the two proposed adjustment factors. For consistency 
with the historical FTP/HFET weighting of 55 percent and 45 percent, 
respectively, which is used in the current regulations for compliance 
and other testing, we believe that this same 55 percent/45 percent 
weighting for FTP and HFET test results is appropriate for the 
adjustment factors proposed in this action.\26\
---------------------------------------------------------------------------

    \26\ The proposed test procedure adjustments would apply to 
testing on all federal Tier 3 gasoline certification fuels, 
including premium certification fuel and LEVIII fuels.
---------------------------------------------------------------------------

A. CO2 Adjustment Factor and Approach to Other GHG Exhaust 
Standards

    For purposes of this proposed action, we analyzed the data from the 
EPA test program (excluding the data from the Acura because of the 
octane sensitivity issue discussed above). Table IV-1 presents our 
calculation process. The data show that the impact of the fuel change 
varies slightly among the vehicles, but it is consistently in the same 
direction and in the range of 1-2.5 percent, with a mean value of 1.66 
percent.

     Table IV-1--CO2 Results of the EPA Test Program for the FTP and HFET Cycles, With Weighted Values for the Two Cycles, and Corresponding Percent
                                                                       Differences
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             FTP                      HFET                  Weighted \1\             Difference \2\
                                                 -------------------------------------------------------------------------------------------------------
                     Vehicle                       Tier 3 (g/   Tier 2 (g/   Tier 3 (g/   Tier 2 (g/   Tier 3 (g/   Tier 2 (g/
                                                      mi)          mi)          mi)          mi)          mi)          mi)         (g/mi)         %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Altima..........................................       270.60       276.19       163.37       165.49       222.35       226.38         4.03         1.81
Civic...........................................       213.37       216.98       143.16       144.75       181.77       184.47         2.70         1.49
F150............................................       376.87       380.61       241.92       244.79       316.14       319.49         3.35         1.06
Malibu 1........................................       307.37       314.53       184.01       189.15       251.86       258.11         6.25         2.48
Malibu 2........................................       268.64       274.00       163.58       166.02       221.36       225.41         4.05         1.83
Mazda...........................................       238.57       242.12       160.32       161.87       203.36       206.01         2.65         1.30
Ram.............................................       414.49       423.94       260.67       262.76       345.27       351.41         6.14         1.78
Silverado.......................................       419.88       427.69       281.05       281.37       357.41       361.84         4.44         1.24
Volvo...........................................       299.83       305.98       173.22       175.61       242.86       247.31         4.46         1.84
Silverado (2b)..................................       706.83       721.57       443.11       447.66       588.16       598.31        10.15         1.73
                                                 -------------------------------------------------------------------------------------------------------
    Mean........................................  ...........  ...........  ...........  ...........  ...........  ...........  ...........         1.66
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ As 0.55FTP + 0.45HFET.
\2\ As T2-T3, and as 100 (T2-T3)/T3.

    The formula for combining and weighting CO2 test results 
is straightforward:

CO2 = 0.55 x CO2city + 0.45 > 
CO2highway

Where:

CO2 = weighted CO2 in grams per mile
CO2city = CO2 as measured on the FTP test 
cycle
CO2highway = CO2 as measured on the HFET test 
cycle

    Based on the results of the analysis of test data in Table IV-1, 
EPA proposes that measured CO2 from FTP and HFET testing on 
Tier 3 test fuel, weighted as discussed above (55/45 percent), be 
adjusted by multiplying by a factor of 1.0166 to produce the expected 
CO2 performance had the vehicle been tested over the same 
test cycles while operating on Tier 2 fuel. In other words, the 
CO2 emissions test results from a vehicle being tested for 
GHG compliance using Tier 3 test fuel would be multiplied by this 
factor to arrive at the CO2 value used for compliance.\27\ 
For example, the compliance CO2 value would be computed as 
1.0166 x (0.55 x CO2,FTP + 0.45 x CO2,HFET). We 
welcome comment on the proposed value for this factor and on the 
approach we used to determine it.
---------------------------------------------------------------------------

    \27\ Compliance for the LD GHG standards is based on all carbon-
related exhaust emissions (CREE). The adjustment factor applies only 
to the CO2 emission aspect of the CREE equation. For 
discussion of CREE impacts in the EPA test program, see memo 
``Carbon-related Exhaust Emissions (CREE) Measured on Current and 
Proposed Certification Gasolines,'' submitted by Jim Warila to 
docket EPA-HQ-OAR-2016-0604.
---------------------------------------------------------------------------

1. Methane and Nitrous Oxide Emissions Compliance
    We also propose that, with the transition to Tier 3 test fuel for 
CAFE and CO2 requirements, compliance with the separate GHG 
standards for methane (CH4) and nitrous oxide 
(N2O) (or the related alternative standards optional program 
\28\) also be determined using only the results from testing with the 
Tier 3 test fuel, on the same proposed implementation schedule 
discussed in Section V below and synchronized with the parallel 
CO2 testing. Manufacturers test for these additional GHG 
emissions in conjunction with the primary CO2 testing, and 
this proposed parallel provision eliminates the need for redundant 
testing on both fuels for CH4 and N2O 
certification.
---------------------------------------------------------------------------

    \28\ 40 CFR 86.1818-12(f)(1) through (3).
---------------------------------------------------------------------------

    Unlike CO2, these emission components are overwhelmingly 
affected by catalytic converter performance. If there is a change in 
engine-out emissions (i.e., ahead of the catalyst), due to the change 
in certification fuel, that change will be small, and we likewise 
expect any change in post-catalyst tailpipe emissions from the change 
in certification fuel to also be small, if there is one at all. If 
there were any small changes in tailpipe emissions from the change in 
fuel, we do not

[[Page 28574]]

expect they would affect a vehicle's compliance with the standards for 
these pollutants, since these are ``cap'' standards set at specific 
levels to prevent future backsliding (rather than fleet-average 
standards intended to achieve reductions in the emission levels of the 
current and future vehicle fleet). For these reasons, we are not 
proposing any changes to these cap standards nor any other adjustments 
to the CH4 and N2O test results when using the 
Tier 3 test fuel. We welcome any comment and data relative to the 
CH4 and N2O cap standards.

B. Fuel Economy (CAFE) Adjustment Factor

1. Analysis of Data and Development of the Proposed Fuel Economy 
Equation
    As we did with the CO2 test data above, we used the EPA 
test program results (again, excluding the Acura) to determine an 
adjustment factor that would be applied to the FTP and HFET results for 
test vehicles operating on Tier 3 test fuel to produce CAFE fuel 
economy results equivalent to those from testing on Tier 2 test fuel. 
Tier 2 test fuel is the result of EPA's 1986 test fuel changes and the 
associated adjustment, designed to produce results that represent the 
CAFE fuel economy that would have been observed under 1975 test 
conditions (as required by the statutes governing the CAFE program and 
discussed in Section I.C above). The CAFE fuel economy adjustment 
proposed here would align Tier 3 test fuel testing with Tier 2 test 
fuel results, and, by extension, with results that would have been 
observed using 1975 test fuel.
    Note that the proposed adjustment factor would also be used for all 
other test cycles required for fuel economy labeling, as further 
discussed in Section VII below. This current section summarizes EPA's 
analysis and the resulting value we are proposing for the CAFE fuel 
economy adjustment factor. As discussed above in Section II, a 
vehicle's CAFE fuel economy is based primarily on the same measured 
CO2 emissions that determine its compliance with the GHG 
standards. For the reasons discussed in that section, the CAFE 
calculation is necessarily more complex than the direct CO2 
emissions measurement, and adjusting the calculation carries these 
complexities.
    To provide NHTSA with the fuel economy data it uses for CAFE 
compliance, EPA uses calculations that account for the difference in 
volumetric energy density (VED, e.g., Btu/gal) of the test fuel 
relative to the baseline test fuel on which NHTSA based the original 
CAFE standards in 1975. In the mid-1980s, when EPA last made such a 
test-fuel related adjustment, empirical data available to the Agency 
suggested that there was not a direct, 1-to-1 response of fuel economy 
to changes in test fuel VED. Because of this, EPA proposed and took 
final action to insert an additional factor, called the ``R-factor,'' 
into the equation. EPA defined this R-factor, established in the 
regulations with a value of 0.6, as the percent change in fuel economy 
per percent change in test fuel VED. For example, for R = 0.6, a 10 
percent decrease in test fuel VED would only produce a 6 percent 
decrease in fuel economy.
    Table IV-2 shows this R=0.6 adjusted fuel economy value alongside 
the carbon-balance fuel economy for both test fuels. The VED of the 
Tier 2 fuel was higher than the 1975 CAFE reference fuel, so the R-
factor adjustment reduces the fuel economy result slightly relative to 
the carbon-balance value. For Tier 3 test fuel, which has lower VED, 
the R-factor adjustment increases the fuel economy result slightly. If 
the adjustment were functioning optimally (i.e., if R=0.6 were exactly 
the right adjustment for both fuels), we'd expect the corrected value 
in the R=0.6 columns in Table IV-2 to be the same value for both test 
fuels. However, there is still 55a directionally consistent offset, 
with the Tier 3 test fuel values slightly lower than the Tier 2 values 
for all but one vehicle, suggesting that an R-factor of 0.6 is not 
optimal and should be higher for this test fleet operating on Tier 3 
fuel. A higher value is also supported by analyses of other recent 
datasets.\29\
---------------------------------------------------------------------------

    \29\ Sluder, C., West, B., Butler, A., Mitcham, A. et al., 
``Determination of the R Factor for Fuel Economy Calculations Using 
Ethanol-Blended Fuels over Two Test Cycles,'' SAE Int. J. Fuels 
Lubr. 7(2):551-562, 2014.

                                   Table IV-2--Carbon-Balance and R-Adjusted Fuel Economy Results by Vehicle and Fuel
                                                           [City/highway-weighted values, mpg]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Tier 2 test fuel \a\                              Tier 3 test fuel \b\
                                                     ---------------------------------------------------------------------------------------------------
                                                         C-balance equation         R=0.6 equation         C-balance equation         R=0.6 equation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Altima..............................................                    39.40                    39.26                    38.51                    39.10
Civic...............................................                    48.43                    48.26                    47.16                    47.88
F150................................................                    27.97                    27.87                    27.12                    27.53
Malibu 1............................................                    34.49                    34.37                    34.00                    34.52
Malibu 2............................................                    39.61                    39.48                    38.72                    39.31
Mazda...............................................                    43.38                    43.23                    42.16                    42.81
Ram.................................................                    25.42                    25.34                    24.83                    25.22
Silverado...........................................                    24.66                    24.58                    23.96                    24.32
Volvo...............................................                    36.08                    35.95                    35.24                    35.78
Silverado (2b)......................................                    14.90                    14.85                    14.56                    14.79
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ For the Tier 2 fuel, we calculated the adjusted fuel economy using ASTM methods D3343 and D3338, and lumped THC emission term, consistent with how
  fuel economy is calculated and reported under the current requirements.
\b\ For the Tier 3 fuel, we used modified methods D3343 and D3338, and separate NMOG and CH4 emission terms as specified in this proposal. The reason
  for the change in emission terms is explain in more detail below.

    Because of the remaining offset seen in Table IV-2, we are 
proposing an updated fuel economy equation for use with Tier 3 test 
fuel where the R-factor is replaced by a new factor (Ra), 
determined empirically so as to make the fleet-average fuel economy 
result using Tier 3 test fuel numerically equivalent to the fleet-
average result using Tier 2 test fuel and R=0.6. The goal is to have no 
change in stringency for compliance with fuel economy standards with 
the new test fuel. Note that this new factor not only updates the 
sensitivity of fuel economy to VED (the

[[Page 28575]]

main purpose of the original R-factor) but also accommodates other 
changes to the calculation discussed in more detail below. For 
reference, we show the current equation for Tier 2 test fuel (which we 
described in Section II above) here: \30\
---------------------------------------------------------------------------

    \30\ We present the equations below in a form that highlights 
the changes between the existing and proposed CAFE equations. These 
equations are functionally equivalent to those in the proposed 
regulatory language associated with this notice (Sec.  600.113-12), 
with the latter equations structured in form conventionally used for 
CAFE compliance purposes. This proposed regulatory language also 
defines each of the terms in these CAFE equations.
[GRAPHIC] [TIFF OMITTED] TP13MY20.004

    One of these proposed changes to the equation is an update from 
using THC emissions in the Tier 2 carbon-balance denominator to using 
NMOG and CH4 with Tier 3 test fuel, where NMOG is determined 
as specified in 40 CFR 1066.635. The inclusion of NMOG better accounts 
for the oxygenated emission products resulting from ethanol in the test 
fuel, and is consistent with the use of NMOG in the Tier 3 emission 
standards. With the very low emission levels of Tier 3 vehicles, we 
expect the difference between THC and the sum of NMOG + CH4 
to be negligible. We request comment and any data regarding this 
proposed change to the equation.
[GRAPHIC] [TIFF OMITTED] TP13MY20.005

    A second change we are proposing to the fuel economy calculation is 
to update the test methods used in determining specific gravity (SG), 
carbon mass fraction (CMF), and net heat of combustion (NHC). As 
indicated earlier, EPA designed the existing CAFE equation around the 
use of E0 test fuel, and specified that these fuel parameters be 
determined using ASTM methods D1298, D3343, and D3338, respectively. 
The latter two methods determine the unknown fuel property by 
mathematical correlation to other known properties, and these 
correlations are not suitable for ethanol blends as published. 
Therefore, we are proposing additional calculations to be used with 
D3343 and D3338 to determine CMF and NHC of E10 test fuel. These 
modified methods have been previously described in EPA guidance and 
other technical literature, and are specified in detail in the proposed 
regulations included as part of this notice.\31\ As a simplification, 
we request comment on omitting water and sulfur adjustments in these 
calculations because their impact is negligible (less than 0.05% of FE, 
combined) over the allowable ranges in test fuel. We are also proposing 
that method D4052 be adopted as equivalent to D1298 for determining SG. 
We request comment on the potential use of other methods for fuel 
property determination for fuel economy calculation, including the 
analytical methods D5291 for CMF and D4809 for NHC.
---------------------------------------------------------------------------

    \31\ EPA Guidance Letter CD-95-09 and SAE technical paper 930138 
describe adjustment of ASTM D3338 and D3343 results for oxygenates. 
More detail on accommodation of ethanol's volatility impact in the 
ASTM methods can be found in the memo ``Distillation adjustment for 
ethanol blending in Tier 3 and LEVIII test fuels,'' May 2, 2018, 
submitted by Aron Butler to docket EPA-HQ-OAR-2016-0604.
---------------------------------------------------------------------------

    In deriving the appropriate value to propose for Ra, 
i.e., the value that produces the equivalent fuel economy with Tier 3 
E10 test fuel, we used the current Tier 2 methods and R=0.6 when 
calculating the fuel economy using Tier 2 test fuel, and the proposed 
updated methods when using Tier 3 test fuel. Because of the proposed 
changes to the measurement methods discussed in the previous paragraph 
and the new Ra factor being specific to Tier 3 test fuel, 
this proposed new equation would not be valid for reporting fuel 
economy when testing using Tier 2 fuel. We are proposing to incorporate 
the small impacts of these calculation formula changes within the 
single new Ra factor. We request comment on the 
appropriateness of this approach, versus another approach such as 
requiring correction(s) for the fuel property test method(s) separate 
from a factor serving the purpose of the existing R-factor.
    As with the proposed CO2 adjustment factor, for the CAFE 
adjustment factor we weighted the results from city (FTP) and highway 
(HFET) testing in the EPA test program as follows:
[GRAPHIC] [TIFF OMITTED] TP13MY20.006

    Our analysis of the study data as described shows that a value of 
Ra=0.81 produces a fleet average fuel economy difference 
very close to zero between the two test fuels. Table IV-3 compares the 
adjusted city/highway weighted fuel economy for each study vehicle as 
it is currently calculated with Tier 2 fuel to the adjusted fuel 
economy on Tier 3 fuel using the updated calculations and an 
Ra value of 0.81. At the right-hand side of the table is the 
percent difference by vehicle, with the fleet average difference of 
near zero shown at the bottom.

       Table IV-3--Adjusted Fuel Economy Results by Vehicle and Fuel Showing Impact of Proposed Ra Factor
                                         [City/highway-weighted values]
----------------------------------------------------------------------------------------------------------------
                                           Tier 2 test fuel         Tier 3 test fuel
                                               (R=0.6)                 (Ra=0.81)          Tier 3 vs. Tier 2 (%)
----------------------------------------------------------------------------------------------------------------
Altima...............................                    39.26                    39.32                     0.16
Civic................................                    48.26                    48.15                    -0.23
F150.................................                    27.87                    27.69                    -0.65
Malibu 1.............................                    34.37                    34.72                     1.02
Malibu 2.............................                    39.48                    39.54                     0.15

[[Page 28576]]

 
Mazda................................                    43.23                    43.05                    -0.41
Ram..................................                    25.34                    25.36                     0.09
Silverado............................                    24.58                    24.46                    -0.46
Volvo................................                    35.95                    35.98                     0.08
Silverado (2b).......................                    14.85                    14.87                     0.14
                                      --------------------------------------------------------------------------
    Average difference...............  .......................  .......................                    -0.01
----------------------------------------------------------------------------------------------------------------

    Figure IV-1 shows the percent change in city/highway weighted fuel 
economy when moving from Tier 2 to Tier 3 test fuel using three 
computation methods. The bottom series (with square markers) shows the 
difference using the carbon-balance calculation, which makes no 
adjustment for VED and therefore is the best estimate of the actual, 
real-world effect. The middle series (with round markers) shows the 
difference calculated using the appropriate CAFE formula and fuel 
property measurements for each test fuel and R=0.6 for both (the values 
shown in Table IV-2). Finally, the top series (dashed with triangular 
markers) shows the effect of adjusting the R-factor in the Tier 3 
equation to a value of 0.81. The difference of approximately 0.6 
percent between the top and middle lines is the fuel economy reduction 
due to the test fuel change that would be mitigated by the proposed R-
factor update. The top line in this figure corresponds to the right-
hand column in Table IV-3.
[GRAPHIC] [TIFF OMITTED] TP13MY20.007

2. Proposed Fuel Economy Adjustment Factor
    As described above, the fuel economy difference between the fuels, 
as shown in the analysis presented in Figure IV-1is very near zero with 
an Ra factor of 0.81. Thus, we propose to adopt this value 
for adjustment of fuel economy values from testing on Tier 3 fuel to 
equivalent values under 1975 test conditions and test fuel. We also 
propose to use the same fuel economy equation form and Ra 
factor for any tests performed on LEVIII fuel (which

[[Page 28577]]

manufacturers sometimes choose to and are allowed to use), given that 
its carbon content and VED closely match those of Tier 3 test fuel. EPA 
requests comment on the methodology we used to determine the proposed 
value for Ra, and on the proposed value itself.

V. Proposed Implementation Schedule

    Testing required for compliance with light-duty vehicle GHG 
emission and CAFE standards, as well as for fuel economy labeling, is 
substantial, and comprises the majority of all necessary yearly vehicle 
emissions testing performed by manufacturers.\32\ This is also 
generally the case with compliance with standards for large pickup 
trucks and vans (i.e., the heavy-duty Class 2b and 3 vehicle GHG and 
fuel consumption standards. Because of the quantity of testing 
required, manufacturers typically plan testing with sufficient lead 
time to stagger the necessary testing among their limited testing 
facilities, often over several years. Key to this approach to managing 
testing is the ability of manufacturers to ``carry over'' the test 
results for some specific vehicle models, often for several years, thus 
avoiding the need to re-test the same vehicle model in sequential model 
years when little or no change to the vehicle model has occurred (see 
40 CFR 86.1839).
---------------------------------------------------------------------------

    \32\ Tier 3 (non-GHG) testing is done according to ``test 
groups,'' with testing on one worst-case vehicle normally covering a 
number of vehicle models within the test group. While the non-GHG 
emission characteristics are treated as the same across the models 
in the test group (using the worst case model), GHG and CAFE values 
typically vary significantly among the models in the test group, 
resulting in many times more required tests.
---------------------------------------------------------------------------

    At the time of the Tier 3 final rule in 2014 (discussed in Section 
I.B above), we anticipated that it would be possible for EPA to 
organize and complete the vehicle testing program undergirding this 
proposal (discussed in Section III above), and propose and finalize the 
necessary test procedure adjustments soon thereafter. In that final 
rule, at 79 FR 23532, EPA said that ``. . . [A]t the present time, EPA 
expects to have the needed data in early to mid 2015 and will then be 
in a position to conduct a thorough assessment of the impacts of 
different emission test fuels on Tier 3/LEV III vehicles and develop 
any appropriate adjustments and changes, in consultation and 
coordination with NHTSA.'' At the same time, we also recognized in that 
final rule, at page 23533, that timing projections leading to setting 
the mandatory use of Tier 3 fuel for MY 2020, along with the needed 
adjustments, ``are subject to revision based on timing of the 
completion of the future action and the data and record developed in 
that future rulemaking.''
    Thus, the expectation of EPA and the industry at the time was that 
if EPA took the necessary actions expeditiously, sufficient 
transitional time would be available to avoid disruption of 
manufacturer testing plans. Since the EPA actions are now well underway 
but final action on the adjustments is still some months away, the 
timing situation is now different. Today, necessary testing for MY 2020 
production has begun. For this reason, EPA now believes that additional 
time is warranted before manufacturers are required to do all of their 
necessary GHG and fuel economy testing on Tier 3 fuel and with the test 
procedure adjustments proposed in this notice. This would avoid the 
need for manufacturers to immediately test all of their vehicle models 
on Tier 3 fuel, instead of being able to continue to use carryover data 
developed using Tier 2 fuel and the existing factors for some of their 
vehicle models.
    Therefore, we are proposing a limited phased implementation of this 
requirement that we believe will avoid such disruption for 
manufacturers of light-duty vehicles, light-duty trucks, and MDPVs, 
allowing them to continue into the near future the widespread practice 
of using ``carry-over'' Tier 2 E0 test data for certification of later 
model year vehicles. Specifically, we propose to implement the required 
use of Tier 3 fuel and the proposed test procedure adjustment factors 
for GHG and fuel economy reporting in four phases. First, because EPA 
will likely now be issuing a final rule for this proposal later in 
2019, we propose to delay the start of Tier 3 test fuel testing for 
GHGs and fuel economy for one model year, until MY 2021. This proposed 
provision would have the simple effect of extending without change the 
current test-fuel related requirements for one model year, such that 
all GHG and fuel economy testing would continue to be performed on Tier 
2 E0 fuel. Second, for MYs 2021 through 2022, we propose that 
manufacturers have the option of testing vehicles for GHG and fuel 
economy on either Tier 2 or Tier 3 test fuel (with Tier 3 test fuel 
testing incorporating the associated adjustment factors proposed in 
this notice).
    Next, to ensure continued progress toward Tier 3 fuel testing, for 
MYs 2023 and 2024 we propose that manufacturers perform all GHG and 
fuel economy testing of new vehicle models (i.e., those that do not use 
carryover criteria emission data) on Tier 3 fuel. For vehicle models 
essentially unchanged from an earlier model year, we propose that 
manufacturers be able to use carryover GHG and fuel economy test data 
from testing on earlier model year vehicles using Tier 2 fuel, so long 
as the manufacturer and EPA consider that data to be appropriate for 
that vehicle model. Finally, beginning in MY 2025, we propose that all 
testing for GHG and fuel economy reporting (including carryover 
testing) would need to be performed on Tier 3 test fuel and use the 
proposed test procedure adjustment factors.
    We also propose to apply the same phased implementation schedule to 
heavy-duty Class 2b and 3 vehicles,\33\ with the exception that the 
option to test on Tier 3 fuel would begin with MY 2022 instead of MY 
2021 (MY 2022 is the first year of the Tier 3 test fuel requirement for 
those vehicles under the Tier 3 program).
---------------------------------------------------------------------------

    \33\ These vehicles, primarily pickups and large vans, are 
tested using similar test procedures and calculations to those that 
apply to light-duty vehicles.
---------------------------------------------------------------------------

    Finally, as stated above, we recognize that the time it has taken 
EPA to propose, and will take to finalize, these provisions will 
necessarily extend beyond the time that most manufacturers will need to 
begin testing for the 2020 model year, sales for which a manufacturer 
may choose to begin as early as January 2, 2019. Again, our intention 
is to avoid disruption of manufacturer testing plans during the 
transition to Tier 3 E10 test fuel. Therefore, until this proposal is 
finalized, a manufacturer may request in writing to perform fuel 
economy testing for 2020 MY vehicles on Tier 2 E0 test fuel, based on 
the ``special procedures'' provisions of 40 CFR 1066-10(c) and 40 CFR 
1065-10(c)(2). EPA would expect to approve such requests because a 
vehicle cannot be appropriately tested on Tier 3 E10 test fuel until 
EPA finalizes the adjustment factors proposed in this action. Test 
results produced in this way would be acceptable for all regulatory 
purposes, including compliance with fuel economy labeling requirements 
and compliance with CAFE and GHG emissions standards. Upon EPA's 
issuing of a final rule for this proposed rule, the phased 
implementation process proposed in this action (or as revised based on 
comments) would become effective and replace any interim use of special 
procedures.
    Because the fundamental purpose of the proposed test procedure 
adjustments is to maintain program stringency during the transition to 
Tier 3 fuel, we do not believe that this proposed phased delay in the 
requirement for

[[Page 28578]]

manufacturers to test on Tier 3 test fuel will result in any changes in 
overall emission levels from the fleet (or in vehicle technology costs) 
(See Section VI below). EPA requests comment on this proposed approach 
to implementing the transition to exclusive use of Tier 3 test fuel.

VI. Projected Impacts

    This proposed action is designed to ensure that the changes in 
vehicle test fuel characteristics occurring under existing regulations 
do not affect the stringency of the current GHG and fuel economy 
standards or unnecessarily add to manufacturer testing burdens. As a 
result, this proposed action by design should not result in any 
significant changes in the emissions or fuel consumption benefits 
originally projected for the EPA GHG or the DOT CAFE programs, nor any 
significant changes in the projected incremental technology costs of 
the standards to manufacturers.
    As we discuss in Section IV above, we derived the proposed test 
procedure adjustments on a fleetwide average basis. Thus, it is 
possible that vehicle manufacturers may find that for some individual 
vehicle models the proposed adjustments result slightly different 
certification CO2 emissions and fuel economy calculations in 
one direction or the other. Overall, because manufacturers also certify 
on a fleet-average basis, we believe that the proposed adjustment 
factors would result in no significant net changes in certification 
results for manufacturers. In addition, as noted above, adjustments to 
the test procedure are necessary to maintain the same level of 
stringency for the GHG and CAFE standards. As also noted above, we 
believe that model-by-model adjustment factors would be so unwieldly 
and burdensome on both EPA and manufacturers that an averaging approach 
is more appropriate. We request comment on this conclusion, including 
any data or information indicating that the proposed approach would be 
problematic for any individual manufacturer's fleet.
    Regarding the additional certification vehicle testing that the 
transition from Tier 2 to Tier 3 test fuel now underway will 
temporarily require, we discuss in Section V above a proposed 
implementation schedule for the transition to required use of Tier 3 
test fuel (with the associated test procedure adjustments proposed 
here). As discussed in Section V above, we believe that the proposed 
phased implementation schedule will minimize any potential disruption 
of any manufacturer's current testing plans. Because the purpose of 
this rule is to align certification results before and after the 
transition in test fuels, the proposed gradual implementation, 
including the proposed delay until MY 2021 for the required use of Tier 
3 fuel, should have no impact on the projected benefits and costs of 
the GHG and CAFE programs.

VII. Implications of Proposed Adjustments on the Fuel Economy and 
Environment Label

A. Background

    Prior to introducing a vehicle into commerce, manufacturers are 
required to perform testing to generate the fuel economy and GHG 
emission performance estimates that will be displayed on the Fuel 
Economy and Environment Label (window sticker on new cars and light 
trucks). This testing is performed by the manufacturer on one or more 
versions of a given vehicle model (e.g. Ford F150 Regular cab, Super 
cab, Supercrew cab). Testing for the label is based on EPA regulations 
and guidance, generally using an average of the projected highest 
volume versions of a vehicle model that they plan to build for that 
coming model year.\34\ The results are used to determine the city and 
highway fuel economy estimates, and the CO2 performance 
level that will be displayed on the window sticker to provide consumers 
important information when making purchasing decisions. Under the 
interim Tier 3 fuel economy requirements described in 40 CFR 600.117, 
the fuel economy and CO2 performance values are currently 
based on testing using Tier 2 E0 test fuel.
---------------------------------------------------------------------------

    \34\ The minimum data requirements for labeling are outlined in 
40 CFR 600.010(c) and EPA Advisory Circular 83A (https://iaspub.epa.gov/otaqpub/publist1.jsp).
---------------------------------------------------------------------------

    As described in 40 CFR 600.210-12, the fuel economy label city and 
highway ratings are calculated using one of two primary methods 
permitted under the labeling requirements. The first method is the 5-
cycle methodology where the FTP and HFET and three additional test 
cycles (US06, SC03, Cold FTP), are used in a set of formulas that 
weight the different portions of the five test cycles to produce the 
city and highway fuel economy rating for the label.\35\ The 5-cycle 
formulas result in city and highway fuel economy estimates displayed on 
the label that have been adjusted to more accurately represent the fuel 
economy that customers can expect to achieve in the real world.
---------------------------------------------------------------------------

    \35\ The three additional cycles account for more extreme 
driving conditions, like higher speeds and accelerations, air 
conditioning use, and cold ambient temperatures.
---------------------------------------------------------------------------

    The other method is the derived 5-cycle methodology, where the city 
and the highway label values are determined using a correlation from a 
large data set of 5-cycle results across different vehicle types. The 
derived 5-cycle methodology reduces the number of tests required to 
two, the FTP and HFET.\36\ However, the derived 5-cycle correlation 
method requires an initial check on the certification emission-data 
vehicle that is used to demonstrate compliance with criteria pollutant 
emission standards for the FTP (city), HFET (highway), US06, SC03 and 
Cold FTP tests. The fuel economy results of these five tests are used 
for the initial check to determine whether fuel economy label testing 
may be performed using the 5-cycle method or the derived 5-cycle 
method. This check is commonly called the ``litmus test'' and it 
determines whether or not the derived 5-cycle method is a reliable 
predictor of 5-cycle fuel economy performance for a given test group. 
Other flexibilities exist in the program if a vehicle meets the litmus 
test criteria for only the FTP test but doesn't meet the litmus test 
criteria for the HFET test. The ``litmus test'' criteria are outlined 
in 40 CFR 600.115-11.
---------------------------------------------------------------------------

    \36\ US06 testing is sometimes required for relatively few 
labels that use the derived 5-cycle method to determine the FE Label 
city estimate and use the modified 5-cycle method to determine the 
FE Label highway estimate. See 40 CFR 600.115-11(b)(2)(ii)(B). In 
the 2017 model year, 54 of 1404 labels (3.8%) used the modified 5-
cycle method to determine the highway fuel economy label estimates.
---------------------------------------------------------------------------

    The CO2 performance of a vehicle is also displayed on 
the label in different forms. The first way CO2 performance 
information is made available on the label is in the form of a 
numerical value in grams/mile determined by the 5-cycle or derived 5-
cycle methods, or, if actual test data was not collected, by an 
analytically derived equivalent value. The second way CO2 
performance is displayed is in the ``Fuel Economy and Greenhouse Gas 
Rating'' horizontal bar scaled from one (worst) to ten (best). The 
rating bar indicates the weighted city and highway CO2 
levels from testing, relative to other vehicles in the same model year. 
Note that similarly to the fuel economy estimates shown on the label, 
the CO2 estimates displayed on the label are also adjusted 
using the 5-cycle or derived 5-cycle formula to more accurately 
represent the (tailpipe) CO2 emissions that customers can 
expect to achieve in the real world.

[[Page 28579]]

B. City and Highway Fuel Economy Estimates Displayed on the Label

    EPA strives to provide accurate Fuel Economy and Environment Label 
estimates to consumers and endeavors to maintain as much consistency as 
possible among vehicles and across model years. The labeling 
methodology adjusts laboratory test results downward to reflect 
multiple real-world variables that are not incorporated into 
dynamometer test results, including roadway roughness, road grade 
(hills), wind, low tire pressure, heavier loads, snow/ice, effects of 
ethanol in gasoline, larger vehicle loads (e.g., trailers, cargo, 
multiple passengers), and others. (See 71 FR 77876). Real-world fuel 
ethanol content has increased since the development of the label 5-
cycle methodology established in 2008, but ethanol energy content is 
only one of many variables that affect fuel economy.
    If the isolated effect of increased ethanol in the new test fuel 
were to be reflected on the label, there could be a one MPG decrease on 
a significant number of vehicle labels as a result of the lower energy 
content of E10, relative to the current methodology. However, there are 
many variables that affect fuel economy, and EPA believes that a 
comprehensive assessment of real world fuel economy is the best process 
to ensure that all real-world effects are reflected. In the future, EPA 
may reassess the label adjustments to determine the overall effect of 
changes over time in real world driving conditions. EPA recognizes that 
individual vehicle mileage will always vary for a number of reasons, 
believes the EPA fuel economy values provide the best currently 
available estimates for typical U.S. drivers and average driving 
conditions, and finds that piecemeal changes to attempt to reflect 
changes due to E10 are not warranted. Therefore, for calculating Fuel 
Economy and Environment label values from testing on Tier 3 E10 test 
fuel, EPA is proposing to apply adjustment factors to the test results, 
such that the values remain consistent with those generated under the 
current program (that is, on Tier 2 E0 test fuel). We invite comment on 
this proposed approach.
    EPA proposes that for a given label, all emission test cycles 
should be performed using the same test fuel and test procedures for 
purposes of determining the fuel economy label estimates. We propose 
that the city and highway fuel economy estimates for labels be 
determined from test results on Tier 3 E10 test fuel, using the 
proposed new fuel economy equation, including the new Ra 
adjustment factor, to align with Tier 2 E0 test fuel results (as 
described in Section IV.B above), beginning with testing for the same 
model year that CAFE and GHG compliance for a vehicle becomes based on 
the new Tier 3 E10 test fuel. This would ensure that the Fuel Economy 
and Environment Label values remain consistent with the respective 
values generated from Tier 2 E0 results under the current program. Note 
that fuel economy label values based on Tier 2 E0 test fuel testing, 
whether the data are new or carried over, would continue to require the 
use of Tier 2 E0 fuel and the current test procedures across all test 
cycles.
    Because the city and highway fuel economy label values can be based 
on the sales-weighted results of different vehicle versions as 
described above, we propose that all the test results used for a sales-
weighted Fuel Economy and Environment Label be based on the same test 
fuel and test procedures. For example, if a manufacturer switches one 
version of a vehicle model used in a sales weighted fuel economy label 
to the new Tier 3 E10 test fuel and test procedures, the other versions 
used for that weighted label must also have results based on the Tier 3 
E10 test fuel. In this example, the fuel economy estimates displayed on 
the label would be calculated using the newly-proposed Tier 3 E10 
gasoline fuel economy equation to align the Tier 3 E10 test fuel 
testing with Tier 2 E0 test fuel results (and then adjusted using the 
5-cycle or derived 5-cycle formula to more accurately represent the 
fuel economy that customers can expect to achieve in the real world).

C. CO2 Performance Estimates Displayed on the Label

    As described above, the CO2 estimates displayed in both 
forms on the Fuel Economy and Environment Label (numerically and 
graphically) represent the same results, in CO2 form, as the 
results used to generate the city and highway fuel economy labels. 
Therefore, we propose that CO2 results from testing on Tier 
3 E10, adjusted by the factor of 1.0166 proposed in Section IV.A, be 
used as input CO2 values for the 5-cycle or derived 5-cycle 
equations used to determine the CO2 information shown on the 
label.\37\ As with the approach proposed for fuel economy label values 
above, this adjustment to the CO2 test results on Tier 3 E10 
fuel would ensure that CO2 label values remain consistent 
with Tier 2 E0 results generated under the current program. We invite 
comment on this approach.
---------------------------------------------------------------------------

    \37\ Consistent with Section VII.B. above, we propose that all 
the test results used for the CO2 estimates for the label 
be based on the same test fuel and test procedures. For example, if 
a manufacturer tests one version of a vehicle model used in a label 
on Tier 3 E10 test fuel and Tier 3 test procedures, the other test 
vehicle versions used for that label must also be tested using Tier 
3 E10 test fuel and test procedures.
---------------------------------------------------------------------------

D. Litmus Test

    As discussed in Section VII. A. above, the ``litmus test'' is 
performed on emission certification vehicles and is used as an initial 
check to determine whether fuel economy label testing may be performed 
using the derived 5-cycle method instead of the full 5-cycle method. 
Currently the provisions of 40 CFR 600.117(d) allow manufacturers to 
perform the litmus test using either Tier 2 E0 test fuel or Tier 3 E10 
test fuel (using the current fuel economy equation), provided all five 
tests use a test fuel with the same nominal ethanol content. Consistent 
with the test procedure changes proposed in this notice, we also 
propose that the ``litmus test'' requirements transition to using Tier 
3 E10 test fuel-based results on the same implementation schedule as 
the proposed GHG and CAFE test procedure adjustments discussed in 
Section IV above.\38\ We invite comment on this proposed approach.
---------------------------------------------------------------------------

    \38\ The litmus test is discussed in more detail in EPA Guidance 
letter CISD-2010-04, ``2011 Fuel Economy Label Implementation.''
---------------------------------------------------------------------------

VIII. Statutory Authority and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is a ``significant regulatory action'' that was 
submitted to the Office of Management and Budget (OMB) for review. Any 
changes made in response to OMB recommendations have been documented in 
the docket.
    This proposed action is designed to ensure that the changes in 
vehicle test fuel characteristics occurring under existing regulations 
do not affect the stringency of the current GHG and fuel economy 
standards or unnecessarily add to manufacturer testing burdens. As a 
result, this proposed action by design should not result in any 
significant changes in the emissions or fuel consumption benefits 
originally projected for the EPA GHG or the DOT CAFE programs, nor any 
significant changes in the projected incremental technology costs of 
the standards to manufacturers. Thus, a regulatory impact evaluation or 
analysis is unnecessary.

[[Page 28580]]

B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs

    This proposed rule is not expected to be subject to the 
requirements of EO13771 because this proposed rule is expected to 
result in no more than de minimis costs.

C. Paperwork Reduction Act (PRA)

    This proposed action would not impose any new information 
collection burden under the PRA, since the proposal would simply adjust 
the calculations already required under the existing CAFE and GHG 
emissions standards. OMB has previously approved the information 
collection activities contained in the existing regulations and has 
assigned OMB control number 2060-0104.

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 
RFA. In making this determination, the impact of concern is any 
significant adverse economic impact on small entities. An agency may 
certify that a rule will not have a significant economic impact on a 
substantial number of small entities if the rule relieves regulatory 
burden, has no net burden or otherwise has a positive economic effect 
on the small entities subject to the rule. This proposed action is 
designed to ensure that the changes in vehicle test fuel 
characteristics occurring under existing regulations do not affect the 
stringency of the current GHG and fuel economy standards or 
unnecessarily add to manufacturer testing burdens. We therefore 
anticipate no costs and therefore no regulatory burden associated with 
this proposed rule. Further, small entities are generally exempt from 
the light-duty vehicles greenhouse gas standards unless the small 
entity voluntarily opts into the program. See 40 CFR 86.1801-12(j). We 
have therefore concluded that this proposed action will have no net 
regulatory burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

    This proposed action does not contain any unfunded mandate as 
described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or 
uniquely affect small governments. The proposed action imposes no 
enforceable duty on any state, local or tribal governments. 
Requirements for the private sector do not exceed $100 million in any 
one year.

F. Executive Order 13132: Federalism

    This proposed action does not have federalism implications. It will 
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 does not have tribal implications as specified 
in Executive Order 13175. This rule only corrects and clarifies 
regulatory provisions that apply to light-duty vehicle manufacturers. 
Tribal governments would be affected only to the extent they purchase 
and use regulated vehicles. Thus, Executive Order 13175 does not apply 
to this action.

H. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    This proposed action is not subject to Executive Order 13045 
because it is not economically significant as defined in Executive 
Order 12866, and because there are no environmental health or safety 
risks created by this action that could present a disproportionate risk 
to children. This proposed rule merely maintains existing regulatory 
provisions.

I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution or Use

    This proposed action is not subject to Executive Order 13211, 
because it is not economically significant as defined in Executive 
Order 12866.

J. National Technology Transfer and Advancement Act (NTTAA)

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. NTTAA directs agencies to provide 
Congress, through OMB, explanations when the Agency decides not to use 
available and applicable voluntary consensus standards. This action 
involves technical standards.
    We are proposing to revise the test procedures as required for 
proper measurement of an ethanol-blended test fuel. Specifically, we 
propose to use the following voluntary consensus standards:
     The current regulation specifies ASTM D3338 for net heat 
of combustion (or net heating value). This method is appropriate for 
neat gasoline, but it is not valid for measuring net heat of combustion 
for gasoline blended with ethanol. We are instead specifying that 
manufacturers must use either ASTM D240 (January 2017) or ASTM D4809 
(May 2013), each of which provides a technically appropriate 
measurement method for net heat of combustion with ethanol-blended 
gasoline.
     The current regulation specifies ASTM D3343 for carbon 
mass fraction of gasoline test fuel. This method is appropriate for 
neat gasoline, but it is not valid for determining carbon mass fraction 
for gasoline blended with ethanol. We are instead specifying that 
manufacturers use ASTM D5291 (May 2010), which provides a technically 
appropriate measurement method for carbon mass fraction with ethanol-
blended gasoline. ASTM D5291 is already the method we specify for 
measuring criteria emissions in Sec.  1065.655.
     The current regulation specifies ASTM D1298 (June 2012, 
reapproved in July 2017) as the method for measuring specific gravity. 
This method is no longer commonly used. As a result, we are proposing 
to specify ASTM D4052 as an upgraded procedure, consistent with 
industry practice.
    If ASTM publishes new versions of these or other standards 
referenced in 40 CFR part 600 before the final rule is completed, we 
intend to reference those updated documents in the final rule.

K. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    The EPA believes that this action is not subject to Executive Order 
12898 (59 FR 7629, February 16, 1994) because it does not establish an 
environmental health or safety standard. This proposed regulatory 
action maintains the effect of a previously established regulatory 
action and as such does not have any impact on human health or the 
environment.

List of Subjects in 40 CFR Part 86

    Administrative practice and procedure, Confidential business 
information, Labeling, Motor vehicle

[[Page 28581]]

pollution, Reporting and recordkeeping requirements.

Andrew Wheeler,
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 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES 
AND ENGINES

0
1. The authority citation for part 86 continues to read as follows:

    Authority: 42 U.S.C. 7401-7671q.

0
2. Amend Sec.  86.1819-14 by revising paragraph (d)(4) to read as 
follows:


Sec.  86.1819-14  Greenhouse gas emission standards for heavy-duty 
vehicles.

* * * * *
    (d) * * *
    (4) Measure emissions using the procedures of subpart B of this 
part and 40 CFR part 1066. Determine separate emission results for the 
Federal Test Procedure (FTP) described in 40 CFR 1066.801(c)(1) and the 
Highway Fuel Economy Test (HFET) described in 40 CFR 1066.801(c)(3). 
Calculate composite emission results from these two test cycles for 
demonstrating compliance with the CO2, N2O, and 
CH4 standards based on a weighted average of the FTP (55%) 
and HFET (45%) emission results. Note that this differs from the way 
the criteria pollutant standards apply. Test fuel requirements apply as 
described in 40 CFR 600.101(c). Multiply measured CO2 
emission results by 1.0166 for vehicles tested with E10 for 
demonstrating compliance with the fleet average CO2 
standard.
* * * * *

PART 600--FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF 
MOTOR VEHICLES

0
3. The authority citation for part 600 continues to read as follows:

    Authority: 49 U.S.C. 32901-23919q, Pub. L. 109-58.

0
4. Amend Sec.  600.011 by revising paragraphs (a) and (b) to read as 
follows:


Sec.  600.011  Incorporation by reference.

    (a) Certain material is incorporated by reference into this part 
with the approval of the Director of the Federal Register under 5 
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that 
specified in this section, the Environmental Protection Agency must 
publish a notice of the change in the Federal Register and the material 
must be available to the public. All approved material is available for 
inspection at U.S. EPA, Air and Radiation Docket and Information 
Center, 1301 Constitution Ave. NW, Room B102, EPA West Building, 
Washington, DC 20460, (202) 202-1744, and is available from the sources 
listed below. It is also available for inspection at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. In addition, these materials are available from the 
sources listed below.
    (b) ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West 
Conshohocken, PA 19428-2959, (610) 832-9585, or http://www.astm.org/.
    (1) ASTM D240-17, Standard Test Method for Heat of Combustion of 
Liquid Hydrocarbon Fuels by Bomb Calorimeter, approved January 1, 2017, 
IBR approved for Sec.  600.113-12(f).
    (2) ASTM D975-13a, Standard Specification for Diesel Fuel Oils, 
approved December 1, 2013, IBR approved for Sec.  600.107-08(b).
    (3) ASTM D1298-12b (Reapproved 2017), Standard Test Method for 
Density, Relative Density, or API Gravity of Crude Petroleum and Liquid 
Petroleum Products by Hydrometer Method, approved July 15, 2017, IBR 
approved for Sec. Sec.  600.113-12(f) and 600.510-12(g).
    (4) ASTM D1945-03 (Reapproved 2010), Standard Test Method for 
Analysis of Natural Gas By Gas Chromatography, approved January 1, 
2010, IBR approved for Sec.  600.113-12(f) and (k).
    (5) ASTM D3338/D3338M-09 (Reapproved 2014), Standard Test Method 
for Estimation of Net Heat of Combustion of Aviation Fuels, approved 
May 1, 2014, IBR approved for Sec.  600.113-12(f).
    (6) ASTM D3343-05 (Reapproved 2010), Standard Test Method for 
Estimation of Hydrogen Content of Aviation Fuels, approved October 1, 
2010, IBR approved for Sec.  600.113-12(f).
    (7) ASTM D4052-16, Standard Test Method for Density, Relative 
Density, and API Gravity of Liquids by Digital Density Meter, approved 
December 1, 2016, IBR approved for Sec.  600.113-12(f).
    (8) ASTM D4809-13, Standard Test Method for Heat of Combustion of 
Liquid Hydrocarbon Fuels by Bomb Calorimeter (Precision Method), 
approved May 1, 2013, IBR approved for Sec.  600.113-12(f).
* * * * *
0
5. Add Sec.  600.101 to subpart B to read as follows:


Sec.  600.101  Testing overview.

Perform testing under this part as described in Sec.  600.111. This 
involves the following specific requirements:
    (a) Perform the following tests and calculations for LDV, LDT, and 
MDPV:
    (1) Testing to demonstrate compliance with Corporate Average Fuel 
Economy standards and greenhouse gas emission standards generally 
involves a combination of two cycles--the Federal Test Procedure and 
the Highway Fuel Economy Test (see 40 CFR 1066.801). Testing to 
determine values for fuel economy labeling under subpart D of this part 
generally involves testing with three additional test cycles; Sec.  
600.210 describes circumstances in which testing with these additional 
test cycles does not apply for labeling purposes.
    (2) Diesel-fueled vehicles are not subject to cold temperature 
emission standards; however, you must test at least one vehicle in each 
test group over the cold temperature FTP to comply with requirements of 
this part. You may omit PM measurements during the cold temperature FTP 
test.
    (3) Calculate fuel economy and CREE values for vehicle 
subconfigurations, configurations, base levels, model types as 
described in Sec. Sec.  600.206 and 600.208. Calculate fleet-average 
values for fuel economy and CREE as described in Sec.  600.510.
    (4) Determine fuel economy values for labeling as described in 
Sec.  600.210 using either the vehicle-specific 5-cycle method or the 
derived 5-cycle method as described in Sec.  600.115.
    (i) For vehicle-specific 5-cycle labels, the test vehicle 
(subconfiguration) data are adjusted to better represent in-use fuel 
economy and CO2 emissions based on the vehicle-specific 
equations in Sec.  600.114. Sections 600.207 and 600.209 describe how 
to use the ``adjusted'' city and highway subconfiguration values to 
calculate adjusted values for the vehicle configuration, base level, 
and the model type. These ``adjusted'' city, highway, and combined fuel 
economy estimates and the combined CO2 emissions for the 
model type are shown on the fuel economy label.
    (ii) For derived 5-cycle labels, calculate ``unadjusted'' fuel 
economy and CO2 values for vehicle subconfigurations, 
configurations, base levels, and model types as described in Sec. Sec.  
600.206 and 600.208. Section 600.210 describes how to use the 
unadjusted model type values to calculate ``adjusted'' model type 
values for city, highway, and combined fuel economy and CO2 
emissions using the derived 5-cycle equations for the fuel economy 
label.

[[Page 28582]]

    (b) Perform the following tests and calculations for chassis-tested 
HDV other than MDPV:
    (1) Test vehicles as described in 40 CFR 86.1816 and 86.1819. 
Testing to demonstrate compliance with CO2 emission 
standards generally involves a combination of two cycles for each test 
group--the Federal Test Procedure and the Highway Fuel Economy Test 
(see 40 CFR 1066.801). Fuel economy labeling requirements do not apply 
for heavy-duty vehicles (except MDPV).
    (2) Determine fleet-average CO2 emissions as described 
in 40 CFR 86.1819-14(d)(9).
    (3) These CO2 emission results are used to calculate 
corresponding fuel consumption values to demonstrate compliance with 
fleet average fuel consumption standards under 49 CFR part 535.
    (c) Manufacturers must use E10 gasoline test fuel as specified in 
40 CFR 1065.710(b) to demonstrate compliance with CO2, 
CH4, and N2O emission standards and determine 
fuel economy values. This requirement starts in model year 2023 for all 
fuel economy and certification testing in test groups that do not use 
carryover data for criteria emission standards, and starting in model 
year 2025 for all other vehicles. Any vehicle that relies on E10 
testing for fuel economy or any greenhouse gases must use the E10 
testing results for all these values. For testing with California ARB's 
E10 gasoline test fuel (LEV III gasoline), all the provisions of this 
part apply as specified for EPA's E10 test fuel. The following interim 
provisions apply:
    (1) Manufacturers may optionally use this E10 gasoline test fuel 
starting in model year 2021 for vehicles subject to standards under 40 
CFR 86.1818, and starting in model year 2022 for vehicles subject to 
standards under 40 CFR 86.1819.
    (2) Section 600.117 describes how to comply using E0 test fuel for 
greenhouse gas standards and fuel economy measurements, and using E10 
test fuel for criteria emission standards.
0
6. Amend Sec.  600.113-12 by revising paragraphs (f)(1) and (o) and 
adding paragraph (p) to read as follows:


Sec.  600.113-12  Fuel economy, CO2 emissions, and carbon-related 
exhaust emission calculations for FTP, HFET, US06, SC03 and cold 
temperature FTP tests.

* * * * *
    (f) * * *
    (1) Gasoline test fuel properties shall be determined by analysis 
of a fuel sample taken from the fuel supply. A sample shall be taken 
after each addition of fresh fuel to the fuel supply. Additionally, the 
fuel shall be resampled once a month to account for any fuel property 
changes during storage. Less frequent resampling may be permitted if 
EPA concludes, on the basis of manufacturer-supplied data, that the 
properties of test fuel in the manufacturer's storage facility will 
remain stable for a period longer than one month. The fuel samples 
shall be analyzed to determine fuel properties as follows for neat 
gasoline (E0) and for a low-level ethanol-gasoline blend (E10):
    (i) Specific gravity. Determine specific gravity using ASTM D4052 
(incorporated by reference in Sec.  600.011). Note that ASTM D4052 
refers to specific gravity as relative density.
    (ii) Carbon mass fraction. (A) For E0, determine hydrogen mass 
percent using ASTM D3343 (incorporated by reference in Sec.  600.011), 
then determine carbon mass fraction as CMF = 1 - 0.01 x hydrogen mass 
percent.
    (B) For E10, determine carbon mass fraction using the following 
equation, rounded to three decimal places.

    CMFf = carbon mass fraction of test fule = CMFh [middot] (1 - MFe) 
+ CMFe [middot] MFe.

Where:

MFe = mass fraction ethanol in the test fuel =
[GRAPHIC] [TIFF OMITTED] TP13MY20.008

VPe = volume percent ethanol in the test fuel as determined by ASTM 
D5599-00 or ASTM D4815-13 (incorporated by reference in Sec.  600.011).
SGe = specific gravity of pure ethanol. Use SGe = 0.7939.
SGf = specific gravity of the test fuel as determined by ASTM D1298-12b 
or ASTM D4052-11.
CMFe = carbon mass fraction of pure ethanol. Use CMFe = 0.5214.
CMFh = carbon mass fraction of the hydrocarbon fraction of the test 
fuel as determined using ASTM D3343 (incorporated by reference in Sec.  
600.011) with the following inputs, using VTier3 or VLEVIII as 
appropriate:
A = aromatics content of the hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.009

G = API gravity of the hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.010

VTier3 = average volatility of the Tier 3 hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.011

VLEVIII = average volatility of the LEV III hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.012

Where:

VParo,f = volume percent aromatics in the test fuel as determined by 
ASTM D1319-15 (incorporated by reference in Sec.  600.011). An 
acceptable alternative method is ASTM D5769-10 (incorporated by 
reference in Sec.  600.011), as long as the result is bias-corrected 
as described in ASTM D1319.
SGh = specific gravity of the hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.013

T10, T50, T90 = the 10, 50, and 90 percent distillation temperatures 
of the test fuel, respectively, in degrees Fahrenheit, as determined 
by D86 (incorporated by reference in Sec.  600.011).

    (iii) Net heat of combustion (MJ/kg). (A) For E0, determine net 
heat of combustion using ASTM D3338/D3338M (incorporated by reference 
in Sec.  600.011).
    (B) For E10, determine net heat of combustion using the following 
equation, rounding the result to the nearest whole number:

NHCf = net neat of combustion of test fule = NHGH [middot] (1 - MFe) + 
NHCe [middot] MFe.

Where:

MFe = mass fraction ethanol in the test fuel =
[GRAPHIC] [TIFF OMITTED] TP13MY20.014

VPe = volume percent ethanol in the test fuel as determined by ASTM 
D5599-00 or ASTM D4815-13 (incorporated by reference in Sec.  
600.011).
SGe = specific gravity of pure ethanol. Use 
SGe = 0.7939.
SGf = specific gravity of the test fuel as determined by 
ASTM D1298-12b or ASTM D4052-11 (incorporated by reference in Sec.  
600.011).
NHCe = net heat of combustion of pure ethanol. Use NHCe = 
11,530 Btu/lb.
NHCh = net heat of combustion of the hydrocarbon fraction of the 
test fuel as determined using ASTM D3338 (incorporated by reference 
in Sec.  600.011) with the following inputs, using VTier3 or VLEVIII 
as appropriate:
A = aromatics content of the hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.015


[[Page 28583]]


G = API gravity of the hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.016

VTier3 = average volatility of the Tier 3 hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.017

VLEVIII = average volatility of the LEV III hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.018

Where:

VParo,f = volume percent aromatics in the test fuel as determined by 
ASTM D1319-15 (incorporated by reference in Sec.  600.011). An 
acceptable alternative method is ASTM D5769-10 (incorporated by 
reference in Sec.  600.011), as long as the result is bias-corrected 
as described in ASTM D1319.
SGh = specific gravity of the hydrocarbon fraction =
[GRAPHIC] [TIFF OMITTED] TP13MY20.019

T10, T50, T90 = the 10, 50, and 90 percent distillation temperatures 
of the test fuel, respectively, in degrees Fahrenheit, as determined 
by D86 (incorporated by reference in Sec.  600.011).
* * * * *
    (o)(1) For testing with E10, calculate fuel economy in miles per 
gallon using the following equation, rounded to the nearest 0.1 
miles per gallon:
[GRAPHIC] [TIFF OMITTED] TP13MY20.020

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.
[rho]H2O = the density of pure water at 60 [deg]F. Use 
[rho]H2O = 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) Use one of the following methods to calculate the carbon-
related exhaust emissions for model year 2017 and later testing with 
the low-level ethanol-gasoline blend test fuel specified in 40 CFR 
1065.710(b):
    (i) For manufacturers not complying with the fleet averaging option 
for N2O and CH4 as allowed under Sec.  86.1818 of 
this chapter, calculate CREE in grams per mile using the following 
equation, rounded to the nearest whole gram per mile:

CREE = (CMF/0.273 x NMOG) + (1.571 x CO) + 1.0166 x CO2 + 
(0.749 x CH4)

Where:

CREE = carbon-related exhaust emissions.
NMOG = grams/mile NMOG as obtained in 40 CFR 1066.635.
CH4 = grams/mile CH4 as obtained in paragraph 
(g)(2) of this section.
CO = grams/mile CO as obtained in paragraph (g)(2) of this section.
CO2 = measured tailpipe grams/mile CO2 as 
obtained in paragraph (g)(2) of this section.
CMF = carbon mass fraction of test fuel as obtained in paragraph 
(f)(1) of this section and rounded according to paragraph (g)(3) of 
this section.

    (ii) For manufacturers complying with the fleet averaging option 
for N2O and CH4 as allowed under Sec.  86.1818 of 
this chapter, calculate CREE in grams per mile using the following 
equation, rounded to the nearest whole gram per mile:

CREE = [(CMF/0.273) x NMOG] + (1.571 x CO) + 1.0166 x CO2 + 
(298 x N2O) + (25 x CH4)

Where:

CREE means the carbon-related exhaust emissions as defined in Sec.  
600.002.
NMOG = Grams/mile NMOG as obtained in 40 CFR 1066.635.
CO = Grams/mile CO as obtained in paragraph (g)(2) of this section.
CO2 = Measured tailpipe grams/mile CO2 as 
obtained in paragraph (g)(2) of this section.
N2O = Grams/mile N2O as obtained in paragraph 
(g)(2) of this section.
CH4 = Grams/mile CH4 as obtained in paragraph 
(g)(2) of this section.
CMF = Carbon mass fraction of test fuel as obtained in paragraph 
(f)(1) of this section and rounded according to paragraph (g)(3) of 
this section.

    (p) Equations for fuels other than those specified in this section 
may be used with advance EPA approval. Alternate calculation methods 
for fuel economy and carbon-related exhaust emissions 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
7. Amend Sec.  600.114-12 by revising paragraphs (d)(2), (e)(3), 
(f)(1), (2), and (4) to read as follows:


Sec.  600.114-12  Vehicle-specific 5-cycle fuel economy and carbon-
related exhaust emission calculations.

* * * * *
    (d) * * *
    (2) To determine the City CO2 emissions, use the 
appropriate CO2 grams/mile values instead of CREE values in 
the equations in this paragraph (d). For fuel economy labels generated 
from E10 test data, use ``A166 CO2'' input values to the 
equations in paragraph (d)(1) of this section (instead of CREE input 
values), where ``A166 CO2'' emissions are equal to the 
measured tailpipe CO2 emissions for the test cycle 
multiplied by a factor of 1.0166 and rounded to the nearest 0.1 grams/
mile.
* * * * *
    (e) * * *
    (3) To determine the Highway CO2 emissions, use the 
appropriate CO2 grams/mile values instead of CREE values in 
the equations in this paragraph (e). For fuel economy labels generated 
from E10 test data, use ``A166 CO2'' input values to the 
equations in paragraphs (e)(1) and (2) of this section (instead of CREE 
input values), where ``A166 CO2'' emissions are equal to the 
measured tailpipe CO2 emissions for the test cycle 
multiplied by a factor of 1.0166 and rounded to the nearest 0.1 grams/
mile.
* * * * *
    (f) * * *
    (1) Four-bag FTP equations. If the 4-bag sampling method is used, 
manufacturers may use the equations in paragraphs (a) and (b) of this 
section to determine city and highway CO2 and carbon-related 
exhaust emissions values. For fuel economy labels generated from E10 
test data, use ``A166 CO2'' input values to the equation in 
paragraph (f)(1) of this section (instead of CREE input values), where 
``A166 CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the

[[Page 28584]]

test cycle multiplied by a factor of 1.0166 and rounded to the nearest 
0.1 grams/mile. If this method is chosen, it must be used to determine 
both city and highway CO2 emissions and carbon-related 
exhaust emissions. Optionally, the following calculations may be used, 
provided that they are used to determine both city and highway 
CO2 and carbon-related exhaust emissions values:
* * * * *
    (2) Two-bag FTP equations. If the 2-bag sampling method is used for 
the 75 [deg]F FTP test, it must be used to determine both city and 
highway CO2 emissions and carbon-related exhaust emissions. 
For fuel economy labels generated from E10 test data, use ``A166 
CO2'' input values to the equation in paragraph (f)(2) of 
this section (instead of CREE input values), where ``A166 
CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the test cycle multiplied by a factor of 
1.0166 and rounded to the nearest 0.1 grams/mile. The following 
calculations must be used to determine both city and highway 
CO2 emissions and carbon-related exhaust emissions:
* * * * *
    (4) To determine the City and Highway CO2 emissions, use 
the appropriate CO2 grams/mile values instead of CREE values 
in the equations in paragraphs (f)(1) through (3) of this section. For 
fuel economy labels generated from E10 test data, use ``A166 
CO2'' input values to the equations in paragraphs (f)(1) 
through (3) of this section (instead of CREE input values), where 
``A166 CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the test cycle multiplied by a factor of 
1.0166 and rounded to the nearest 0.1 grams/mile.
* * * * *
0
8. Revise Sec.  600.117 to read as follows:


Sec.  600.117  Interim provisions.

    The following provisions apply if manufacturers demonstrate 
compliance with greenhouse gas emission standards and determine fuel 
economy values using E0 gasoline test fuel as specified in 40 CFR 
86.113-04(a)(1):
    (a) [Reserved]
    (b) Manufacturers may demonstrate that vehicles comply with Tier 3 
emission standards as specified in 40 CFR part 86, subpart S, during 
fuel economy or greenhouse gas measurements using the E0 gasoline test 
fuel specified in 40 CFR 86.113-04(a)(1), as long as this test fuel is 
used in fuel economy or greenhouse gas testing for all applicable duty 
cycles specified in 40 CFR part 86, subpart S. If a vehicle fails to 
meet a Tier 3 emission standard using the E0 gasoline test fuel 
specified in 40 CFR 86.113-04(a)(1), the manufacturer must retest the 
vehicle using the Tier 3 test fuel specified in 40 CFR 1065.710(b) (or 
the equivalent LEV III test fuel for California) to demonstrate 
compliance with all applicable emission standards over that test cycle.
    (c) If a manufacturer demonstrates compliance with emission 
standards for criteria pollutants over all five test cycles using the 
Tier 3 test fuel specified in 40 CFR 1065.710(b) (or the equivalent LEV 
III test fuel for California), the manufacturer may use test data with 
the same test fuel to determine whether a test group meets the criteria 
described in Sec.  600.115 for derived 5-cycle testing for fuel economy 
labeling. Such vehicles may be tested over the FTP and HFET cycles with 
the E0 gasoline test fuel specified in 40 CFR 86.113-04(a)(1) under 
this paragraph (c); the vehicles must meet the Tier 3 emission 
standards over those test cycles as described in paragraph (b) of this 
section. This paragraph (c) applies only for LDV, LDT, and MDPV.
    (d) Manufacturers may perform testing with the appropriate gasoline 
test fuels specified in 40 CFR 86.113-04(a)(1), 40 CFR 86.213(a)(2), 
and in 40 CFR 1065.710(b) to evaluate whether their vehicles meet the 
criteria for derived 5-cycle testing under 40 CFR 600.115. All five 
tests must use test fuel with the same nominal ethanol concentration. 
This paragraph (d) applies only for LDV, LDT, and MDPV.
    (e) For IUVP testing under Sec.  86.1845, manufacturers may 
demonstrate compliance with greenhouse gas emission standards using a 
test fuel meeting specifications for demonstrating compliance with 
emission standards for criteria pollutants.
0
9. Amend Sec.  600.206-12 by revising paragraphs (a)(1), (2)(ii) and 
(iii) 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) * * *
    (1) If only one set of FTP-based city and HFET-based highway fuel 
economy values is accepted for a subconfiguration at which a vehicle 
configuration was tested, these values, rounded to the nearest tenth of 
a mile per gallon, comprise the city and highway fuel economy values 
for that subconfiguration. If only one set of FTP-based city and HFET-
based highway CO2 emissions and carbon-related exhaust 
emission values is accepted for a subconfiguration at which a vehicle 
configuration was tested, these values, rounded to the nearest gram per 
mile, comprise the city and highway CO2 emissions and 
carbon-related exhaust emission values for that subconfiguration. When 
calculating CO2 values for fuel economy labels generated 
from E10 test data, the FTP-based city and HFET-based highway 
CO2 emissions for a test vehicle (and for the 
subconfiguration), shall be the ``A166 CO2'' emission values 
for that test vehicle, where ``A166 CO2'' emissions are 
equal to the measured tailpipe CO2 emissions for the test 
cycle multiplied by a factor of 1.0166 and rounded to the nearest 0.1 
grams/mile.
    (2) If more than one set of FTP-based city and HFET-based highway 
fuel economy and/or carbon-related exhaust emission values are accepted 
for a vehicle configuration:
    (i) All data shall be grouped according to the subconfiguration for 
which the data were generated using sales projections supplied in 
accordance with Sec.  600.208-12(a)(3).
    (ii) Within each group of data, all fuel economy values are 
harmonically averaged and rounded to the nearest 0.0001 of a mile per 
gallon and all CO2 emissions and carbon-related exhaust 
emission values are arithmetically averaged and rounded to the nearest 
tenth of a gram per mile in order to determine FTP-based city and HFET-
based highway fuel economy, CO2 emissions, and carbon-
related exhaust emission values for each subconfiguration at which the 
vehicle configuration was tested. When calculating CO2 
values for fuel economy labels generated from E10 test data, the FTP-
based city and HFET-based highway CO2 emissions for a test 
vehicle shall be the ``A166 CO2'' emission values for that 
test vehicle, where ``A166 CO2'' emissions are equal to the 
measured tailpipe CO2 emissions for the test cycle 
multiplied by a factor of 1.0166 and rounded to the nearest 0.1 grams/
mile.
    (iii) All FTP-based city fuel economy, CO2 emissions, 
and carbon-related exhaust emission values and all HFET-based highway 
fuel economy and carbon-related exhaust emission values calculated in 
paragraph (a)(2)(ii) of this section are (separately for city and 
highway) averaged in proportion to the sales fraction (rounded to the 
nearest 0.0001) within the vehicle configuration (as provided to the 
Administrator by the manufacturer) of vehicles of each tested 
subconfiguration. Fuel economy values shall be harmonically averaged, 
and CO2 emissions and carbon-related exhaust

[[Page 28585]]

emission values shall be arithmetically averaged. The resultant fuel 
economy values, rounded to the nearest 0.0001 mile per gallon, are the 
FTP-based city and HFET-based highway fuel economy values for the 
vehicle configuration. The resultant CO2 emissions and 
carbon-related exhaust emission values, rounded to the nearest tenth of 
a gram per mile, are the FTP-based city and HFET-based highway 
CO2 emissions and carbon-related exhaust emission values for 
the vehicle configuration. Note that for fuel economy labels generated 
from E10 test data, the vehicle subconfiguration CO2 values 
calculated in paragraph (a)(1) or (a)(2)(ii) of this section as 
applicable (which are used to calculate the configuration 
CO2 values in this paragraph (a)(2)(iii)) are required to be 
``A166 CO2'' values, where ``A166 CO2'' emissions 
are equal to the measured tailpipe CO2 emissions for the 
test cycle multiplied by a factor of 1.0166 and rounded to the nearest 
0.1 grams/mile.
0
10. Amend Sec.  600.207-12 by revising the section heading and 
paragraphs (a)(1) and (2)(ii) 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 
configuration. Note that for fuel economy labels generated from E10 
test data, the vehicle specific 5-cycle based CO2 values 
calculated in paragraph Sec.  600.114-12 are based on ``A166 
CO2'' values, where ``A166 CO2'' emissions are 
equal to the measured tailpipe CO2 emissions for the test 
cycle multiplied by a factor of 1.0166 and rounded to the nearest 0.1 
grams/mile.
    (2) * * *
    (ii) Within each subconfiguration of data, all fuel economy values 
are harmonically averaged and rounded to the nearest 0.0001 of a mile 
per gallon in order to determine 5-cycle city and highway fuel economy 
values for each subconfiguration at which the vehicle configuration was 
tested, and all CO2 emissions values are arithmetically 
averaged and rounded to the nearest tenth of gram per mile to determine 
5-cycle city and highway CO2 emission values for each 
subconfiguration at which the vehicle configuration was tested. Note 
that for fuel economy labels generated from E10 test data, the vehicle 
specific 5-cycle based CO2 values calculated in Sec.  
600.114-12 are based on ``A166 CO2'' values, where ``A166 
CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the test cycle multiplied by a factor of 
1.0166 and rounded to the nearest 0.1 grams/mile.
* * * * *
0
11. Amend Sec.  600.208-12 by revising paragraphs (a)(4)(i) and (4)(ii) 
and adding a new paragraph (b)(3)(iii)(C) to read as follows:


Sec.  600.208-12  Calculation of FTP-based and HFET-based fuel economy, 
CO2 emissions, and carbon-related exhaust emissions for a model type.

    (a) * * *
    (4) Vehicle configuration fuel economy, CO2 emissions, 
and carbon-related exhaust emissions, as determined in Sec.  600.206-
12(a), (b) or (c), as applicable, are grouped according to base level.
    (i) If only one vehicle configuration within a base level has been 
tested, the fuel economy, CO2 emissions, and carbon-related 
exhaust emissions from that vehicle configuration will constitute the 
fuel economy, CO2 emissions, and carbon-related exhaust 
emissions for that base level. Note that for fuel economy labels 
generated from E10 test data, the vehicle configuration CO2 
values calculated in Sec.  600.206-12(a)(2)(iii) (which are used to 
calculate the base level CO2 values in this paragraph 
(a)(4)(i)) are required to be ``A166 CO2'' values, where 
``A166 CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the test cycle multiplied by a factor of 
1.0166 and rounded to the nearest 0.1 grams/mile.
    (ii) If more than one vehicle configuration within a base level has 
been tested, the vehicle configuration fuel economy values are 
harmonically averaged in proportion to the respective sales fraction 
(rounded to the nearest 0.0001) of each vehicle configuration and the 
resultant fuel economy value rounded to the nearest 0.0001 mile per 
gallon; and the vehicle configuration CO2 emissions and 
carbon-related exhaust emissions are arithmetically averaged in 
proportion to the respective sales fraction (rounded to the nearest 
0.0001) of each vehicle configuration and the resultant carbon-related 
exhaust emission value rounded to the nearest tenth of a gram per mile. 
Note that for fuel economy labels generated from E10 test data, the 
vehicle configuration CO2 values calculated in Sec.  
600.206-12(a)(2)(iii) (which are used to calculate the base level 
CO2 values in this paragraph (a)(4)(i)) are required to be 
``A166 CO2'' values, where ``A166 CO2'' emissions 
are equal to the measured tailpipe CO2 emissions for the 
test cycle multiplied by a factor of 1.0166 and rounded to the nearest 
0.1 grams/mile.
* * * * *
    (b) * * *
    (3) * * *
    (iii) * * *
    (C) Note that for fuel economy labels generated from E10 test data, 
the base level CO2 values determined in paragraphs (a)(4)(i) 
and (4)(ii) of this section, as applicable, (which are used to 
calculate the model type FTP-based city CO2 values in this 
paragraph (b)(3)(iii)) are required to be ``A166 CO2'' 
values, where ``A166 CO2'' emissions are equal to the 
measured tailpipe CO2 emissions for the test cycle 
multiplied by a factor of 1.0166 and rounded to the nearest 0.1 grams/
mile.
0
12. Amend Sec.  600.209-12 by revising paragraphs (a) and (b) to read 
as follows:


Sec.  600.209-12  Calculation of vehicle-specific 5-cycle fuel economy 
and CO2 emission values for a model type.

    (a) Base level. 5-cycle fuel economy and CO2 emission 
values for a base level are calculated from vehicle configuration 5-
cycle fuel economy and CO2 emission values as determined in 
Sec.  600.207 for low-altitude tests. Note that for fuel economy labels 
generated from E10 test data, the vehicle specific 5-cycle based 
CO2 values calculated in Sec.  600.114-12 are based on 
``A166 CO2'' values, where ``A166 CO2'' emissions 
are equal to the measured tailpipe CO2 emissions for the 
test cycle multiplied by a factor of 1.0166 and rounded to the nearest 
0.1 grams/mile.
* * * * *
    (b) Model type. For each model type, as determined by the 
Administrator, city and highway fuel economy and CO2 
emissions values will be calculated by using the projected sales and 
fuel economy and CO2 emission values for each base level 
within the model type. Separate model type calculations will be done 
based on the vehicle configuration fuel economy and CO2 
emission values as determined in Sec.  600.207, as applicable. Note 
that for fuel economy labels generated from E10 test data, the vehicle 
specific 5-cycle based CO2 values calculated in Sec.  
600.114-12 are based on ``A166 CO2'' values, where ``A166 
CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the test cycle multiplied by a factor of 
1.0166 and rounded to the nearest 0.1 grams/mile.
* * * * *

[[Page 28586]]

0
13. Amend Sec.  600.210-12 by revising paragraphs (a)(2)(i)(B), 
((ii)(B), (b)(2)(i)(B), and (ii)(B) to read as follows:


Sec.  600.210-12  Calculation of fuel economy and CO2 emission values 
for labeling.

    (a) * * *
    (2) * * *
    (i) * * * (B) For each model type, determine the derived five-cycle 
city CO2 emissions using the following equation and 
coefficients determined by the Administrator:

Derived 5-cycle City CO2 = ({City Intercept{time}  x A) + 
({City Slope{time}  x MT FTP CO2)

Where:

A = 8,887 for gasoline-fueled vehicles, 10,180 for diesel-fueled 
vehicles, or an appropriate value specified by the Administrator for 
other fuels.
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.
MT FTP CO2 = the model type FTP-based city CO2 
emissions determined under Sec.  600.208-12(b), rounded to the 
nearest 0.1 grams per mile. Note that for fuel economy labels 
generated from E10 test data, the MT FTP CO2 input value 
is required to be ``A166 CO2'' values for the model type, 
where ``A166 CO2'' emissions are equal to the measured 
tailpipe CO2 emissions for the test cycle multiplied by a 
factor of 1.0166, rounded to the nearest 0.1 grams per mile, as 
obtained in Sec.  600.208-12(b)(3)(iii).

* * * * *
    (ii) * * *
    (B) For each model type, determine the derived five-cycle highway 
CO2 emissions using the equation below and coefficients 
determined by the Administrator:

Derived 5-cycle Highway CO2 = ({Highway Intercept{time}  x 
A) + ({Highway Slope{time}  x MT HFET CO2)

Where:

A = 8,887 for gasoline-fueled vehicles, 10,180 for diesel-fueled 
vehicles, or an appropriate value specified by the Administrator for 
other fuels.
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.
MT HFET CO2 = the model type highway CO2 
emissions determined under Sec.  600.208-12(b), rounded to the 
nearest 0.1 grams per mile. Note that for fuel economy labels 
generated from E10 test data, the MT HFET CO2 input value 
is required to be ``A166 CO2'' values for the model type, 
where ``A166 CO2'' emissions are equal to the measured 
tailpipe CO2 emissions for the test cycle multiplied by a 
factor of 1.0166, rounded to the nearest 0.1 grams per mile, as 
obtained in Sec.  600.208-12(b)(3)(iii) and Sec.  600.208-12(b)(4).

* * * * *
    (b) * * *
    (2) * * *
    (i) * * * (B) Determine the derived five-cycle city CO2 
emissions of the configuration using the equation below and 
coefficients determined by the Administrator:

    Derived 5-cycle City CO2 = {City Intercept{time}  + 
{City Slope{time}  x 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 configuration FTP-based city 
CO2 emissions determined under Sec.  600.206, rounded to 
the nearest 0.1 grams per mile. Note that for specific labels 
generated from E10 test data, the Config FTP CO2 input 
value is required to be ``A166 CO2'' values for the 
configuration, where ``A166 CO2'' emissions are equal to 
the measured tailpipe CO2 emissions for the test cycle 
multiplied by a factor of 1.0166, rounded to the nearest 0.1 grams 
per mile, as obtained in Sec.  600.206-12(a)(2)(iii).

* * * * *
    (ii) * * * (B) Determine the derived five-cycle highway 
CO2 emissions of the configuration using the equation below 
and coefficients determined by the Administrator:

Derived 5-cycle city Highway CO2 = {Highway Intercept{time}  
+ {Highway Slope{time}  x 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 configuration highway fuel economy 
determined under Sec.  600.206, rounded to the nearest tenth. Note 
that for specific labels generated from E10 test data, the Config 
HFET CO2 input value is required to be ``A166 
CO2'' values for the configuration, where ``A166 
CO2'' emissions are equal to the measured tailpipe 
CO2 emissions for the test cycle multiplied by a factor 
of 1.0166, rounded to the nearest 0.1 grams per mile, as obtained in 
Sec.  600.206-12(a)(2)(iii).

* * * * *
[FR Doc. 2020-07202 Filed 5-12-20; 8:45 am]
BILLING CODE 6560-50-P