Trump Approves New Fuel Economy Rule, Cutting Fleet Target to 34.5 MPG by 2031

President Trump announced Saturday, September 26, that he's approved new federal fuel economy standards, unwinding a Biden-era rule that pushed automakers toward electric vehicles. He called it a win for "American auto workers and car buyers" in a Truth Social post.

Under the Biden administration's 2024 rule, automakers were required to hit a fleetwide average of roughly 50.4 miles per gallon by model year 2031, up from 39.1 mpg, according to Al Jazeera. Trump's new standard cuts that target to about 34.5 mpg by 2031, according to reporting aggregated by Ground News. That's a significant rollback.

The Department of Transportation has not yet released the final rule. Transportation Secretary Sean Duffy posted on X that "a major victory for America's auto workers is COMING MONDAY," though he didn't specify if he meant this exact rule, according to Newsweek. The DOT is expected to formalize the standard this coming Monday, September 28.

What Trump Actually Said

"These new Standards will take the waste out of building cars in America. That means LOWER PRICES, saving families thousands on a new, beautiful, and safe car — Far better than the Environmental Monsters that we were building heretofore," Trump wrote. He claimed executives from General Motors, Ford and Stellantis have all called him wanting to expand U.S. production now that the rule is gone.

On Truth Social, Trump also took a shot at Democrats directly: "The Dumocrats cost our Great Auto Manufacturers Billions, forced Americans into cars they never wanted, and wasted Billions on Chargers that were never built," according to Fox Business. He said his administration is investing $100 billion in American auto manufacturing and thanked Duffy and Commerce Secretary Howard Lutnick.

Ford CEO Jim Farley has previously backed this direction. Speaking to Fox & Friends in December, Farley called the planned rule change "a victory for affordability and common sense," saying it would let Ford "offer more affordability on our popular models" and launch new U.S.-built vehicles.

The Pushback

Not everyone's buying the "lower prices" pitch. Katherine García, director of the Sierra Club's Clean Transportation for All campaign, said in a statement that "families already cannot afford the basics, and now Donald Trump wants to make driving more expensive too." Her argument: less fuel-efficient cars burn more gas, meaning more money spent at the pump and dirtier air.

Atid Kimelman, an attorney at the Natural Resources Defense Council, told Newsweek that "with Americans struggling to afford gasoline that is more than $4 a gallon, the Trump administration is going to force them to pay more at the pump," adding that oil companies stand to get a windfall while everyday drivers cover the cost.

Former Transportation Secretary Pete Buttigieg weighed in too, arguing on social media that "U.S. manufacturing jobs are down under Trump, including in the auto industry. His strategy failed, and so will this," and that lowering standards will "accelerate what he has already been doing: handing the clean tech future to China."

Fuel economy standards affect how much gas a fleet burns. A lower mpg target means more gallons consumed per mile driven, all else equal. Whether that translates into higher household fuel bills depends on what people actually buy and whether cheaper sticker prices offset it. Neither side has released hard numbers on net household cost yet, because the final rule hasn't been published.

The "Mandate" Question

While Trump and Republicans call the Biden rule an "EV mandate," the actual policy is a CAFE fuel-economy target that automakers had to meet across their fleet, using more EVs and hybrids as one route to compliance. Fox Business and Newsweek repeat the "EV mandate" framing from the administration without that clarification. Automakers were never barred from selling gas vehicles. They just had to average out their fleet's efficiency.

The rollback follows a pattern. Trump ended EV tax credits last year through the One Big Beautiful Bill Act and signed congressional resolutions in June killing California's diesel-engine restrictions and EV sales mandates, according to Fox Business.

The final rule text, expected Monday, will settle exactly how far the standards drop and what compliance flexibility automakers get. Until then, both the administration's price-savings claim and critics' pump-price warnings remain projections, not verified outcomes.