DETROIT – Environmental groups sued the Trump administration on Friday, challenging its decision to weaken federal vehicle fuel-economy requirements. The organizations say the rollback will lead to less-efficient vehicles, higher gasoline use and increased pollution.
The administration announced Monday that it was reducing Corporate Average Fuel Economy, or CAFE, standards, which determine how many miles new vehicles must travel on a gallon of gasoline. The move came as the administration negotiated with Iran over reopening the Strait of Hormuz.
Roughly one-fifth of the world’s oil typically moves through the strait each day. The dispute over control of the critical shipping route has driven energy prices sharply higher around the world.
The environmental groups filed a petition for review Friday with the U.S. Court of Appeals. The case names Transportation Secretary Sean Duffy and Jonathan Morrison, administrator of the National Highway Traffic Safety Administration, the agency responsible for setting the standards.
“We’re taking the Trump administration to court for this reckless rollback that prioritizes Big Oil and automaker profits over American families,” Katherine Garcia, director of the Sierra Club’s Clean Transportation for All program, said in a statement. “It is unlawful for Trump to turn back the clock on fuel-efficient cars, forcing drivers to waste more money on gas and communities to breathe toxic air.”
The Sierra Club filed the lawsuit alongside the Center for Biological Diversity, the Conservation Law Foundation, the Environmental Defense Fund and Public Citizen.
Under the revised rule announced by the Transportation Department and NHTSA, the industrywide fleet average for passenger cars and light trucks would be about 34.9 miles per gallon for the 2031 model year. That is down from the projected 50.4 mpg required under standards established by the Biden administration.
The administration said easing the requirements would give consumers more vehicle choices and encourage them to purchase newer, safer models. Experts, however, say weaker fuel-economy rules would not necessarily make vehicles cheaper or automatically lead to stronger sales of new cars and trucks.
Duffy said the rule also eliminates what he called an “illegal mandate” that required automakers to produce more expensive electric vehicles that American families did not want.
Manufacturers have never been required to sell EVs, nor have Americans been forced to buy them. Instead, fuel-economy rules and other clean-vehicle standards encouraged automakers to offer a combination of electric, hybrid-electric and increasingly efficient gasoline-powered vehicles.
The Department of Transportation and NHTSA did not immediately respond to The Associated Press’ request for comment.
Automakers and industry groups largely applauded Monday’s decision, arguing that the Biden-era requirements were overly strict and offered little benefit to consumers.
Environmental organizations, by contrast, condemned the rollback.
“With gas prices at historic highs, Trump picked the worst possible time to roll back federal mileage standards,” David Pettit, an attorney with the Center for Biological Diversity’s Climate Law Institute, said in a statement. “Oil companies will profit from less efficient cars, but drivers will take a hit to their wallets and our kids will breathe dirtier air. We’ll all pay the price for more tailpipe pollutants spewing everywhere from playgrounds to wild places. We’re asking the courts to put a stop to this callous giveaway to Big Oil and Big Auto.”
Gasoline prices have remained near $4.50, while diesel prices have reached unprecedented levels in recent weeks, according to AAA.
The Transportation Department said Monday that the revised rule would reduce annual oil consumption in 2050 by about 1.3 billion barrels compared with 2024 levels. NHTSA, however, had estimated that the 2024 standards would prevent 14 billion gallons of gasoline from being burned by that year.
Federal fuel-economy requirements were introduced during the energy crisis of the 1970s. Over the decades, they have helped improve the average efficiency of vehicles.
President Donald Trump has taken several steps to roll back support for cleaner vehicles in the United States. Those actions include eliminating electric-vehicle tax credits, scrapping vehicle emissions standards, repealing fines for automakers that fail to meet mileage requirements and attempting to halt the nation’s EV charging network expansion.
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Alexa St. John is an Associated Press climate reporter. Follow her on X: @alexa_stjohn. Reach her at ast.john@ap.org.
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