The Biden administration finalized updated fuel-economy standards that are looser than proposed last year so that automakers can now achieve a lower bar over the next decade on new models’ fuel consumption.

Instead of an average fuel economy of about 58 miles per gallon for their fleets, companies must now achieve about a 54 miles per gallon threshold by 2032.

The bar-raising comes after demand for purely electric vehicles flattened in the U.S. following early adoption, failing to meet automakers’ ambitious estimates.

The new targets stand in stark contrast to the 13 miles per gallon that the average U.S. vehicle got when Congress introduced fuel-economy standards in the 1970s, the Department of Transportation said.

The final updated rule requires passenger cars’ fuel economy to increase 2% per year for model years 2027 to 2031 and light trucks’ to increase by the same measure for model years 2029 to 2031. The department said the gradual change will save owners more than $600 in fuel costs over their vehicles’ lifetimes and nealrly 70 billion gallons of gas by 2050.

“Not only will these new standards save Americans money at the pump every time they fill up, they will also decrease harmful pollution and make America less reliant on foreign oil,” U.S. Transportation Secretary Pete Buttigieg said in a press release.

The new rule complements a similarly scaled-back Environmental Protection Agency regulation of tailpipe emissions. Automakers can comply with the new standards with a mix of power train technologies, including hybrids and alternative-fuel vehicles.

LEARN MORE: EV Consideration Falls Further