The Trump administration on Monday finalized weaker Corporate Average Fuel Economy standards for new passenger cars and light trucks, scaling back Biden-era targets that were designed to push fleets toward higher mileage and more electric vehicles.

Under the revised NHTSA rule described by NPR (opens in new tab) and other outlets, automakers would need to improve fleet fuel economy by up to 1% a year, aiming for an average of roughly 34.9 miles per gallon in model year 2031. Biden-era rules had required faster annual gains and targeted about 50.4 mpg on average by 2031.

Transportation Secretary Sean Duffy cast the change as affordability relief, saying the administration was “delivering relief to families and reviving the beating heart of American manufacturing.” Officials estimate the rollback could cut new-vehicle sticker prices by about $1,300. President Donald Trump wrote on Truth Social that the standards would “take the waste out of building cars in America” and mean “LOWER PRICES.”

Environmental and public-health groups condemned the move. Dan Becker of the Center for Biological Diversity’s Safe Climate Transport Campaign told NPR (opens in new tab) the rollback would increase gasoline use and pollution. The American Lung Association’s Harold Wimmer said weaker standards would “create more air pollution, harm health and accelerate climate change.” The Alliance for Automotive Innovation’s John Bozzella said NHTSA’s final rule better aligned standards with “the law and current market conditions.”

Transportation is the largest U.S. source of greenhouse-gas emissions, about 28% of the national total according to EPA figures cited by The Guardian (opens in new tab). A December Trump proposal had estimated higher fuel use and emissions if standards were loosened; Monday’s final rule also ends automakers’ ability to trade EV-related CAFE credits among themselves, according to NPR (opens in new tab)’s account of the NHTSA package.

The final rule also reclassifies small crossover vehicles as passenger cars rather than light trucks, the Washington Examiner (opens in new tab) reported. The Transportation Department estimated the change would flip the mix of new vehicles from about 70% light trucks to 70% passenger cars, and the administration argues that classifying crossovers as trucks, which face lower fuel-economy requirements, had distorted the market.