President Donald Trump said on September 26 that he has approved new fuel economy standards rolling back Biden-era rules. He made the announcement in a Truth Social post.

Trump said the change would lower vehicle prices and help automakers build more cars in the United States. He called the Biden rules a “ridiculous EV mandate.” The final rule had not been released, and the new targets were not detailed.

A prior proposal from the National Highway Traffic Safety Administration would cut the fleetwide target to about 34.5 miles per gallon by 2031. That compares with 50.4 mpg under Biden-era standards. Transportation Secretary Sean Duffy said the final rule would be announced on Monday, September 28.

The CAFE system, created by Congress in 1975, sets average mileage targets for each automaker’s fleet. Weaker standards let companies build more pickups and SUVs, which earn higher profits but burn more fuel.

Critics, including the Sierra Club, said the rollback would raise costs at the pump for families already facing high prices. The group said it would fight the rule.