Trump approves 34.5mpg fuel standards, cutting Biden's 50.4mpg target

President Donald Trump said on 26 September 2026 he had approved new fuel economy standards of about 34.5 miles per gallon fleetwide by model year 2031, replacing a Biden-era target of about 50.4 miles per gallon. Trump announced the change in a post on Truth Social, saying it would end what he called an electric vehicle mandate and lower car prices for families.aljazeera.com+1

The announcement matters because it reverses the trajectory of Corporate Average Fuel Economy (CAFE) standards, the system Congress established in 1975 requiring automakers to meet average fuel economy targets across all cars and light trucks they sell. Under the Biden rules finalised in 2024, fleetwide fuel economy was scheduled to rise from 39.1 miles per gallon to about 50.4 by 2031. Trump's figure would instead sit below the 2024 US fleet average.newsweek.com

What the announcement changes

Trump did not release a final rule with the announcement, and the administration had not immediately published the accompanying text. In his post, Trump wrote that the new standards would "take the waste out of building cars in America" and mean "LOWER PRICES, saving families thousands on a new, beautiful, and safe car." He also said General Motors, Ford and Stellantis executives had told him they wanted to expand manufacturing in the United States.

Transportation Secretary Sean Duffy reposted the announcement saying an update was "COMING MONDAY", and separately wrote that "a major victory for America's auto workers" was coming Monday, without specifying whether he meant the fuel economy standards. A White House spokesperson referred questions to Duffy's post. The National Highway Traffic Safety Administration (NHTSA), the agency that sets the standards, had not released a final rule as of 26 September 2026.wgme.com

The 34.5 miles per gallon figure comes from a December 2025 proposal by NHTSA, which projected a fleetwide average of roughly 34.5 miles per gallon by 2031, compared with approximately 50.4 under Biden-era standards. That proposal was more than 30 percent lower than the Biden rule. It was not immediately clear whether the standards Trump referenced match that proposal or contain additional changes, and final technical details were not immediately released.

Where the mpg figures came from

The Biden-era rules did not require consumers to buy electric vehicles, though Trump and Republicans have described the requirements as an "EV mandate". There are no federal guidelines or laws that require Americans to buy electric cars or bar the sale of petrol-powered ones. NHTSA has argued that prior fuel economy standards relied too heavily on projected electric-vehicle adoption and compliance credits, an interpretation the agency says conflicts with federal law.

NHTSA estimated its earlier proposal would reduce the average upfront cost of a new vehicle by about $930. The same agency projected the proposal would increase fuel consumption by roughly 100 billion gallons through 2050, add about $185 billion in fuel spending, and raise carbon dioxide emissions by approximately 5 percent. In December, Duffy said the "Freedom Means Affordable Cars" proposal was projected to save Americans $109 billion over five years and save families $1,000 on the average new vehicle.

What the proposal would cost drivers

Atid Kimelman, an attorney at the Natural Resources Defense Council, said the change would raise costs for drivers, saying that with gasoline above $4 a gallon, the administration would force people to pay more at the pump. Pete Buttigieg, who served as transportation secretary under Biden, replied that lowering standards would hand clean technology to China while raising pump prices. Michael Hartrick said earlier that prior standards were unachievable given slowing EV sales, while Dave Cooke said the approach looked only at worst performers.

The rollback is expected to give automakers more flexibility to produce gasoline-powered pickups and SUVs, which generally have lower fuel efficiency but higher profit margins. Congress has already ended federal tax credits for new, used and commercial electric vehicles acquired after 30 September 2025, including a credit worth up to $7,500, and moved to block California's rules requiring all new passenger vehicle sales to be zero-emission by 2035. Trump said the new standards would help bring manufacturing jobs and investment to Michigan, Ohio, Indiana and South Carolina. The final rule's text and technical details remain unreleased, and Duffy's announcement is scheduled for Monday.