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In August, the National Highway Traffic Safety Administration (NHTSA) proposed to strengthen vehicle fuel-economy standards. Since then, the Environmental Protection Agency has finalized its update to the social cost of greenhouse gases and the Office of Management and Budget has finalized its revisions to Circular A-4. In light of these updates, we submitted a supplemental comment letter reasserting our call for NHTSA to assess regulatory impacts using the best available economics.

In August 2023, the National Highway Traffic Safety Administration (NHTSA) proposed a regulation to strengthen corporate average fuel economy standards for passenger cars, light trucks, and heavy-duty pickup trucks and vans. In a comment letter, we explain that while the Proposed Rule and its accompanying regulatory impact analysis offer useful starting points, NHTSA should take further steps to ensure the complete presentation of regulatory benefits and costs and should select a regulatory option that best promotes social welfare, consistent with the agency’s legal obligations. We also submitted joint comments with a coalition of other environmental groups on NHTSA’s use of the social cost of greenhouses gases in the Proposed Rule.

In May 2022, the National Highway Traffic Safety Administration (NHTSA) finalized a rule to increase its corporate average fuel economy (CAFE) standards for passenger cars and light trucks for model years 2024–2026. A group of fuel and petrochemical manufacturers and states challenged the standards in the U.S. Court of Appeals for the D.C. Circuit, arguing primarily that the Energy Policy and Conservation Act bars NHTSA from including electric vehicles in the analytical baseline for the new standards. Our amicus brief explains that longstanding administrative guidance and case law direct agencies to develop baselines that reflect their best assessment of the real world absent any new agency action. In the context of this rulemaking, that guidance and case law required NHTSA to project how many and what kinds of vehicles—including electric (and plug-in hybrid electric) vehicles—would be built and sold if it did not issue new CAFE standards, which is what NHTSA did here. Our amicus brief also explains that NHTSA has consistently prepared baselines for prior CAFE standards in this manner.

We submitted comments on NHTSA's proposed car standards, recommending ways that the agency could improve its modeling and address inconsistences between its and EPA's analyses. We also submitted joint comments on NHTSA's use of the social cost of carbon, recommending that the agency expand its justification of its discount rates and inclusion of global damages in the SCC.

The National Highway Traffic Safety Administration ("NHTSA") sets corporate average fuel economy ("CAFE") standards for light-duty vehicles, and penalizes automobile manufacturers who fail to meet applicable standards. In January 2021, NHTSA issued an Interim Final Rule repealing the inflation-adjusted penalty increase for Model Years 2019-2021, which we commented was untimely and disregarded critical environmental harms. 

In August 2021, NHTSA proposed to rescind the Interim Final Rule. We filed comments supporting the proposal for complying with inflation-adjustment obligations, driving fuel savings, and reducing pollution.

The National Highway Traffic Safety Administration's interim final rule delays the application of its 2016 inflation adjustment of the penalty for violating the corpoate average fuel-economy (CAFE) standards. We submitted comments explaining that the rule is untimely under the Inflation Adjustment Act, whose deadlines to amend the intial catch-up inflation adjustment expired years ago.

We filed an amicus brief explaining how NHTSA and EPA's decision to finalize a rule that, even under their own analysis, will be net-costly to society, is arbitrary and capricious. 

The Environmental Protection Agency and National Highway Traffic Safety Administration used several gimmicks and faulty assumptions to skew the analysis of the rollback rule, obscuring just how harmful it is to the American public. We published a series of reports examining several of the flaws.

The mistake of setting corporate fuel-economy penalties just a little too low can be magnified by automakers’ decisions to produce millions of cars with worse fuel-economy. And the Trump penalty appears to be way too low to motivate compliance. Here’s a breakdown of the reduced penalty and how it will likely affect cars, consumers, and our climate.

The National Highway Traffic Safety Administration (NHTSA) recently finalized a rule that significantly reduces the penalties that automakers pay for violating the corporate average fuel economy (CAFE) standards. In reducing the penalty, NHTSA rolled back an adjustment that had been made to the penalty under the Inflation Act, a statute requiring agencies to adjust civil monetary penalties to account for decades of inflation. We submitted an amicus brief in the Court of Appeals for the Second Circuit focusing on NHTSA’s faulty economic justifications for the rule, arguing that this repeal was unlawful.