[Federal Register Volume 91, Number 5 (Thursday, January 8, 2026)]
[Rules and Regulations]
[Pages 553-555]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-00154]
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DEPARTMENT OF ENERGY
10 CFR Part 474
[EERE-2025-VT-0073]
RIN 1904-AG09
Petroleum-Equivalent Fuel Economy Calculation
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Final rule, technical amendment.
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SUMMARY: The U.S. Department of Energy (DOE) is amending its
regulations in compliance with a United States Court of Appeals for the
Eighth Circuit court decision vacating the March 29, 2024 rule revising
procedures for calculating a value for the petroleum-equivalent fuel
economy of electric vehicles (EVs) used by the Environmental Protection
Agency (EPA)
[[Page 554]]
in calculating light-duty vehicle manufacturers' compliance with the
Department of Transportation's (DOT) Corporate Average Fuel Economy
(CAFE) standards.
DATES: This action is effective on January 8, 2026. However, the
opinion had legal effect on September 5, 2025.
FOR FURTHER INFORMATION CONTACT: Mr. Kevin Stork, U.S. Department of
Energy, U.S. Department of Energy, Vehicle Technologies Office, EE-3V,
1000 Independence Avenue SW, Washington, DC 20585. Telephone: (202)
586-8306. Email: [email protected].
SUPPLEMENTARY INFORMATION: The Energy Policy and Conservation Act
(EPCA) requires the Secretary of Transportation to set fuel economy
standards for automobiles produced in, or imported into, the United
States. 49 U.S.C. 32902. EPCA, as amended, requires the Secretary of
Energy to determine the equivalent petroleum-based fuel economy values
for various classes of electric vehicles for the purpose of determining
compliance with these fuel economy standards. 49 U.S.C. 32904(a)(2)(B).
On March 29, 2024, DOE issued a final rule that revised the
procedure for calculating a value for the petroleum-equivalent fuel
economy for EVs and revised the value for the petroleum-equivalency
factor (PEF). 89 FR 22041 (Mar. 29, 2024) (2024 Final Rule). In the
2024 Final Rule, DOE calculated the petroleum-equivalency factor by
multiplying four values: (1) a cumulative gasoline-equivalent energy
content of electricity; (2) a fuel content factor (FCF); (3) an
accessory factor (AF); and (4) a driving pattern factor (DPF). 89 FR
22041, 22053. DOE asserted that this methodology reflected the
Secretary's consideration of each statutory factor. The 2024 Final Rule
adopted the following PEF values for electric vehicles starting in
Model Year 2027: \1\
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\1\ The 2024 Final Rule did not revise the methodology or the
PEF value for MY 2024-2026 EVs, thus the PEF value for those model
years remain 82,049 Wh/gal.
Table 1--Revised PEF Values in the 2024 Final Rule for MY 2027-2030 EVs and Later
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Model year CEg FCF AF DPF PEF
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2027............................ 28,996 1/0.3625 1.0 1.0 79,989
2028............................ 28,996 1/0.575 1.0 1.0 50,427
2029............................ 28,996 1/0.7875 1.0 1.0 36,820
2030 and later.................. 28,996 1.0 1.0 1.0 28,996
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On April 5, 2024, the states of Iowa, Arkansas, Florida, Idaho,
Kansas, Mississippi, Missouri, Montana, Nebraska, Ohio, Oklahoma,
Texas, Utah, and the American Free Enterprise Chamber of Commerce filed
a petition for review in the United States Court of Appeals for the
Eighth Circuit. Iowa, et al. v. Wright (Case No. 24-1721 (8th Cir.)).
In a September 5, 2025, opinion, the Eighth Circuit granted the
petition for review, vacated the 2024 Final Rule, and remanded the
proceedings to DOE. Specifically, the court ruled, among other things,
that the fuel content factor was illegal or otherwise contrary to
statute. Because the court vacated the 2024 Final Rule, the previous
petroleum equivalency factor rule springs back into effect. Menorah
Med. Ctr. v. Heckler, 768 F.2d 292, 297 (8th Cir. 1985) (``Unless
special circumstances are present . . . prior regulations remain [in
place] until replaced by a valid regulation or invalidated by a
court.'').
In this final rule, DOE amends its regulations in compliance with
the September 5, 2025, court decision. It removes the revisions adopted
in the 2024 Final Rule and amends the regulatory text so that it reads
as it appeared before the 2024 Final Rule went into effect.
This final rule is not subject to the requirement to provide prior
notice and an opportunity for public comment pursuant to 5 U.S.C.
553(b)(B). DOE finds good cause to waive the requirement to provide
prior notice and an opportunity for public comment as such procedure is
unnecessary. DOE is complying with the order of a Federal court and has
no discretion to do otherwise. In implementation of that order, DOE is
removing 2024 Final Rule. Comments suggesting any other course would
serve no useful purpose.
Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this final
rule; technical amendment.
List of Subjects in 10 CFR Part 474
Corporate average fuel economy, Electric (motor) vehicle, Electric
power, Energy conservation, Fuel economy, Motor vehicles, Research.
Signing Authority
This document of the Department of Energy was signed on December
31, 2025, by Audrey Robertson, Assistant Secretary for Critical
Minerals and Energy Innovation, pursuant to delegated authority from
the Secretary of Energy. That document with the original signature and
date is maintained by DOE. For administrative purposes only, and in
compliance with requirements of the Office of the Federal Register, the
undersigned DOE Federal Register Liaison Officer has been authorized to
sign and submit the document in electronic format for publication, as
an official document of the Department of Energy. This administrative
process in no way alters the legal effect of this document upon
publication in the Federal Register.
Signed in Washington, DC, on January 6, 2026.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE amends part 474 of
Chapter II of Title 10 of the Code of Federal Regulations as set forth
below:
PART 474--ELECTRIC AND HYBRID VEHICLE RESEARCH, DEVELOPMENT, AND
DEMONSTRATION PROGRAM; PETROLEUM-EQUIVALENT FUEL ECONOMY
CALCULATION
0
1. The authority citation for part 474 continues to read as follows:
Authority: 49 U.S.C. 32901 et seq.
0
2. Amend Sec. 474.2 by revising the definition for ``Petroleum-
equivalency factor'' to read as follows:
Sec. 474.2 Definitions.
* * * * *
Petroleum equivalency factor means the value specified in Sec.
474.3(b) of this part, which incorporates the parameters listed in 49
U.S.C. 32904(a)(2)(B) and is used to calculate petroleum-equivalent
fuel economy.
* * * * *
0
3. Amend Sec. 474.3 by
[[Page 555]]
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a. Revising the introductory text of paragraph (b); and
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b. Removing paragraphs (c), (d), (e), and (f)
The revision reads as follows:
Sec. 474.3 Petroleum-equivalent fuel economy calculation.
* * * * *
(b) The petroleum-equivalency factors for electric vehicles are as
follows:
* * * * *
0
4. Add Sec. 474.5 to read as follows:
Sec. 474.5 Review and Update.
The Department will review part 474 five years after the date of
publication as a final rule to determine whether any updates and/or
revisions are necessary. DOE will publish a notice in the Federal
Register soliciting stakeholder input in this review. The Department
will publish the findings of the review and any resulting adjustments
to part 474 in the Federal Register.
0
5. Revise appendix A to part 474 to read as follows:
Appendix to Part 474--Sample Petroleum-Equivalent Fuel Economy
Calculations
Example 1: An electric vehicle is tested in accordance with
Environmental Protection Agency procedures and is found to have an
Urban Dynamometer Driving Schedule energy consumption value of 265
Watt-hours per mile and a Highway Fuel Economy Driving Schedule
energy consumption value of 220 Watt-hours per mile. The vehicle is
not equipped with any petroleum-powered accessories. The combined
electrical energy consumption value is determined by averaging the
Urban Dynamometer Driving Schedule energy consumption value and the
Highway Fuel Economy Driving Schedule energy consumption value using
weighting factors of 55 percent urban, and 45 percent highway:
combined electrical energy consumption value = (0.55 * urban) +
(0.45 * highway) = (0.55 * 265) + (0.45 * 220) = 244.75 Wh/mile
Since the vehicle does not have any petroleum-powered
accessories installed, the value of the petroleum equivalency factor
is 82,049 Watt-hours per gallon, and the petroleum-equivalent fuel
economy is:
[GRAPHIC] [TIFF OMITTED] TR08JA26.037
Example 2: The vehicle from Example 1 is equipped with an
optional diesel-fired cabin heater/defroster. For the purposes of
this example, it is assumed that the electrical efficiency of the
vehicle is unaffected.
Since the vehicle has a petroleum-powered accessory installed,
the value of the petroleum equivalency factor is 73,844 Watt-hours
per gallon, and the petroleum-equivalent fuel economy is:
[GRAPHIC] [TIFF OMITTED] TR08JA26.038
[FR Doc. 2026-00154 Filed 1-7-26; 8:45 am]
BILLING CODE 6450-01-P