LDN News - Environmental groups sue Trump administration over eased vehicle fuel economy rules

Environmental groups sue Trump administration over eased vehicle fuel economy rules

[October 03, 2026] By ALEXA ST. JOHN

DETROIT (AP) — A group of environmental organizations sued the Trump administration on Friday over its recent relaxation of key vehicle fuel economy rules, a decision that the group says will make vehicles less efficient, contribute to more pollution and increase gas consumption.

On Monday, the Trump administration lowered Corporate Average Fuel Economy, or CAFE, standards that set out how far new vehicles need to travel on a gallon of gasoline. The announcement was made as the Trump administration negotiated with Iran over reopening the Strait of Hormuz.

About a fifth of the world's oil passes through the strait on a typical day, and the fight over its control has sent energy prices soaring across the globe.

The environmental groups filed the petition for review Friday in the U.S. Court of Appeals against Transportation Secretary Sean Duffy and Jonathan Morrison, the administrator of the National Highway Traffic Safety Administration, which sets the rules.

“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 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 Center for Biological Diversity, the Conservation Law Foundation, the Environmental Defense Fund and Public Citizen, along with the Sierra Club, filed the suit.

The Transportation Department and NHTSA earlier this week lowered the standards to an industry fleetwide average of roughly 34.9 miles per gallon for passenger cars and light trucks in the 2031 model year, down from a projected 50.4 miles per gallon under rules set by the Biden administration.

The administration said the change would provide Americans more vehicle choice and encourage consumers to buy newer, safer vehicles. Experts say reducing fuel economy requirements in vehicles does not necessarily lower their cost, nor would it automatically translate to new vehicle sales.

Duffy said the new rule also cuts the “illegal mandate that forced automakers to produce more expensive electric vehicles that American families didn’t want.”

There has never been a mandate that manufacturers sell EVs or Americans buy them; the rules and other cleaner vehicle standards incentivized automakers to sell a mix of electric, hybrid electric and increasingly-efficient gasoline-powered vehicles.

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President Donald Trump speaks during an event on fuel economy standards in the Oval Office of the White House, Dec. 3, 2025, in Washington. (AP Photo/Evan Vucci, File)

When reached for comment, a DOT spokesperson referred to statements made by Duffy: "This administration understands the freedom of every American family starts with affordable cars. That’s why our new standards will make that dream more achievable by letting auto manufacturers produce the cars that fit families’ needs at a lower price.”

Auto companies and industry groups broadly welcomed Monday's change, saying the rules under the Biden administration were too stringent and did not benefit consumers.

But environmental organizations decried the changes.

“With gas prices at historic highs, Trump picked the worst possible time to roll back federal mileage standards,” David Pettit, an attorney at 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.”

Gas prices have hovered around $4.50 and diesel has hit unprecedented heights in recent weeks, according to AAA.

The DOT said Monday that the rule would cut yearly oil consumption in 2050 by about 1.3 billion barrels as compared with yearly oil consumption in 2024, but NHTSA had estimated the 2024 standards would have saved 14 billion gallons of gasoline from being burned by that year.

Fuel economy requirements have been in place since the 1970s energy crisis, and over time, have led to improved average efficiency in vehicles.

President Donald Trump has made a number of moves to undercut cleaner vehicles in the U.S. These include eliminating electric vehicle tax credits; scrapping vehicle emissions standards; repealing the fines for automakers who don’t meet mileage rules; and attempting to block the nation’s EV charging buildout.

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