The Trump administration unveiled new fuel economy standards on Monday, rolling back Biden-era rules aimed at cutting down emissions and encouraging more consumers to switch to electric vehicles.

Established by Congress in 1975, the Corporate Average Fuel Economy (CAFE) standards dictate how many miles vehicles must be able to drive on a gallon of fuel, with specific standards for light-duty vehicles, as well as medium- and heavy-duty trucks. 

Over time, automakers have gradually improved their vehicles’ average fuel efficiency. 

Under the new Trump administration rule, the National Highway Traffic Safety Administration (NHTSA) estimates that the new standards will lead to a fleetwide average of 34.9 miles per gallon by model year 2031 — down from a projected 50.4 miles per gallon in 2031 under rules put in place by the Biden administration.

In a statement Monday, the Department of Transportation said the new rules will lower the upfront cost of new vehicles by an average of $1,300 and give automakers more choice regarding the types of cars they manufacture.

“Thanks to President Trump’s leadership, we have finally ended the illegal mandate that forced automakers to produce more expensive electric vehicles that American families didn’t want,” Transportation Secretary Sean P. Duffy said in a statement on Monday.

The Department of Transportation said the rule will help save Americans $138 billion over the next five years. However, it comes at a time when drivers are spending significantly more money at the pump as the war with Iran disrupts the global flow of fuel. Gasoline prices averaged $4.47 on Monday, according to the AAA, up from $2.98 a gallon before the war.