California-led coalition asks appeals court to review NHTSA fuel economy rule

OAKLAND, Oct 2 — California Attorney General Rob Bonta on Friday led a coalition of 26 states, counties and cities in asking the U.S. Court of Appeals for the First Circuit to review a National Highway Traffic Safety Administration (NHTSA) final rule on fuel economy standards for new passenger cars and light trucks, Bonta's office said.²

The petition for review, dated October 2, 2026, challenges the rule titled "Safer Affordable Fuel-Efficient Vehicles Rule III for Model Years 2022 to 2031 Passenger Cars and Light Trucks," published at 91 Fed.¹ Reg.¹ 61,988 on Sept 30.¹

The coalition alleges the rule is arbitrary and capricious and violates the Administrative Procedure Act and the Energy Policy and Conservation Act, according to the press release from Bonta's office.²

The release said the coalition alleges NHTSA contravenes its mandate from Congress to set fuel-economy standards at their "maximum feasible" level.² It said the standards for the next five years require less efficiency than what the U.S. fleet achieved in 2021.²

"California will not stand idly by, we will defend fuel economy standards that keep costs down, protect public health, and build a better, sustainable future," Bonta said.²

The release also said the rule will end the corporate average fuel economy (CAFE) credit trading program in 2028, and that NHTSA tries to paper over nearly $220 billion in lost fuel savings.²

The petition names NHTSA, Administrator Jonathan Morrison and Transportation Secretary Sean Duffy as respondents.¹ It lists the City of Los Angeles among the petitioners, which the release's list of coalition members does not name.²

The petition said it is related to California v.¹ NHTSA, the consolidated challenges to NHTSA's rule "Resetting the Corporate Average Fuel Economy Program," published June 11, 2025.¹ That rule set out NHTSA's reinterpretation of the statutes governing the federal fuel-economy program, which the petition said is the foundation for the new rule.¹

By consent of the parties, that case was placed in abeyance to await the finalization of the new rule, according to the petition.¹