US NHTSA proposes to relax MY 2022-2031 CAFE fuel economy standards
4 December 2025
US National Highway Traffic Safety Administration (NHTSA) issued a notice of proposed rulemaking (NPRM) that would relax the existing Corporate Average Fuel Economy (CAFE) standards for light duty vehicles (passenger cars and light trucks). The proposal—which covers vehicle model years (MY) 2022 through 2031—would amend the NHTSA CAFE regulations for MY 2022-2026 and for MY 2027-2031.
The NHTSA proposal follows the Trump administration policy goal to eliminate the “electric vehicle (EV) mandate” that was established by the prior administration. If the existing CAFE standards were enforced, they would require that an increasing proportion of new vehicles be zero tailpipe emission vehicles—the standards are too stringent to be met by improvements of combustion engine technology alone. CAFE enforcement for MY 2025 has already been suspended by the One Big Beautiful Bill Act, which reduced the 2025 CAFE penalty rate applicable to manufacturers that fail to meet CAFE standards to zero.
Under the NHTSA proposal:
- For passenger cars, the fuel economy standards would increase by 0.5% per year for model years 2023 through 2026, followed by 0.35% in model year 2027, and 0.25% from model year 2029 to 2031.
- For light trucks, NHTSA is proposing an increase of 0.5% for model year 2023 through 2026, followed by 0.7% in model year 2027, and 0.25% from model year 2029 to 2031.
- In terms of miles per gallon, NHTSA estimates that the proposed standards would achieve a fleet average fuel economy of 34.5 mpg by model year 2031.
For comparison, the CAFE standards issued in June 2024 require an industry-wide fleet average of approximately 50.4 mpg for passenger cars and light trucks in MY 2031. (The above fuel economy figures are CAFE values, which are significantly different from EPA fuel efficiency labels and the real world fuel economy.)
The proposed standards would also eliminate the CAFE credit trading program starting in model year 2028. The CAFE credit trading “artificially propped up the EV industry at the expense of traditional automakers,” said the Department of Transportation (DOT) in a press release.
A 45-day public comment period will begin when the proposal is published in the Federal Register, and a public hearing will be held at a later date.
The parallel greenhouse gas emission standards by the Environmental Protection Agency (EPA) that also (indirectly) regulate fuel economy by setting GHG emission limits still remain in power. However, the EPA has proposed to rescind the GHG Endangerment Finding—a 2009 determination that greenhouse gases are a threat to the public health and welfare. If finalized, this action would repeal all GHG emission standards for light-duty, medium-duty, and heavy-duty vehicles and engines.
Source: NHTSA | Reuters