The federal government built one of its biggest tools to curb gasoline use and boost EVs. The Trump administration moved to dismantle it

Federal mileage rules that have guided new cars and light trucks for decades are set for a sharp cutback. The New York Times reported that the Trump administration planned to take that step on Monday through a final Transportation Department rule.

President Trump said on Saturday on social media that he had “just approved new Fuel Economy Standards.” He also said President Joseph R. Biden Jr. had put in place an “E.V. mandate.” The Times described that claim as false. Transportation Secretary Sean Duffy said in a separate social media post that the announcement would come Monday.

The Times said the rule was expected to weaken standards that have pressed automakers to squeeze more miles from gasoline models and to sell more electric vehicles.

New 2031 target sits far below the Biden-era mileage requirement

Congress first created the mileage program in 1975 after an oil embargo by Middle Eastern countries, the Times reported. Automakers have since increased the range of conventional cars on a tank of gas and added more hybrid and electric models.

Under the Biden administration, the standard stood at 50.4 miles per gallon for cars and light trucks. A proposed rule issued in December instead called for an average of 34.5 miles per gallon in model year 2031, the Times reported.

Mr. Trump said easing the rules would lower the price of new cars by thousands of dollars. Congress has already removed fines for companies that miss the targets, the Times reported, and the paper said that the change left the Monday action largely symbolic.

The Times also noted that drivers have faced higher pump prices since U.S.-Israeli attacks on Iran began in February. AAA put the national average at $4.48 a gallon on Saturday.

The mileage rollback sits alongside other recent federal changes, the Times reported. In February, the Environmental Protection Agency ended all federal limits on planet-warming pollution from cars. Lawmakers last year repealed tax credits of up to $7,500 for new electric cars and blocked California from imposing its own stricter auto-pollution limits.

Ending the fines had already saved automakers hundreds of millions of dollars, the Times reported. The paper said the latest move could steer more production toward large pickup trucks and sport utility vehicles, which it described as the most profitable models in the short term.

The Times reported that U.S. firms that slow electric vehicle work could fall behind foreign rivals. It said electric vehicle sales have grown quickly outside the United States as fuel prices rose during the war in the Middle East.

Transportation is the country’s largest source of greenhouse gases, such as carbon dioxide, the Times reported. Beyond cars, the administration’s rollback of climate initiatives includes plans to dismantle a $368 million deep ocean monitoring system.

The Biden administration tightened mileage rules as part of its climate plan. Mr. Trump has called climate change a “hoax” and made criticism of electric vehicles a regular campaign theme. He said Biden-era policy would ban ordinary cars and force drivers into electric models. The Times described those claims as false.

The Sierra Club said Saturday that it planned to sue. Katherine Garcia, director of the group’s Clean Transportation for All campaign, said, “Americans need relief from high costs, but instead Trump is giving automakers a free pass on pollution and handing families the bill – at the pump and with their health.” She also said, “The Sierra Club will fight this senseless rollback every step of the way.”

The Alliance for Automotive Innovation, which represents most major carmakers, did not immediately comment, the Times reported. The group had previously argued that the Biden rules were hard for many of its members to meet.