DETROIT (AP) — New vehicles sold in the United States will have to travel an average of at least 40 miles per gallon of gasoline in 2026 under new rules unveiled Friday by the government.

The National Highway Traffic Safety Administration said its fuel economy requirements will undo a rollback of standards enacted under former President Donald Trump. The new requirements increase gas mileage by 8% per year for model years 2024 and 2025 and 10% in the 2026 model year.

For the current model year, standards enacted under Trump require the fleet of new vehicles to get just over 24 miles per gallon in real-world driving.

Agency officials say the requirements are the maximum that the industry can achieve over the time period and will reduce gasoline consumption by more than 220 billion gallons over the life of vehicles, compared with the Trump standards.

Trump's administration rolled back fuel economy requirements so they rose 1.5% per year, which environmental groups said was inadequate to limit planet-warming greenhouse gas emissions that fuel climate change.

But the new standards won't immediately match those adopted through 2025 under President Barack Obama. NHTSA officials said they will equal the Obama standards by 2025 and slightly exceed them for the 2026 model year.

The Obama-era standards automatically adjusted for changes in the type of vehicles people are buying. When they were enacted in 2012, 51% of new vehicle sales were cars and 49% SUVs and trucks. Last year, 77% of new vehicle sales were SUVs and trucks, which generally are less efficient than cars.

Some environmental groups said the new requirements from NHTSA under President Joe Biden don't go far enough to fight global warming.

"Climate change has gotten much worse, but these rules only require automakers to reduce gas-guzzling slightly more than they agreed to cut nine years ago," said Dan Becker, director of the Safe Climate Transport Center at the Center for Biological Diversity.

He said the final rule is about 2 mpg short of the strongest alternative that NHTSA considered.

Officials said that under the new standards, owners would save about $1,400 in gasoline costs during the lifetime of a 2029 model year vehicle. Carbon dioxide emissions would drop by 2.5 billion metric tons by 2050 under the standards, the NHTSA said.

The agency did not give figures for how much the standards would increase the cost of vehicles. Auto dealers say more stringent requirements drive up prices and push people out of an already expensive new-car market.

The NHTSA sets fuel economy requirements, while the Environmental Protection Agency develops limits on greenhouse gas emissions. NHTSA officials said their requirements nearly match rules adopted in December by the EPA, so automakers don't have to comply with two rules.