The final standards, which govern the release of carbon dioxide from the tailpipes of cars and light trucks, roughly translate into fleet-wide fuel economy values of 55 miles per gallon in model year 2026.
The standards also are expected to encourage more electric vehicle sales, hastening an industry shift that is already under way, with nearly all major automakers having promised to transition their fleets to zero-emission models.
The EPA’s August proposal would have capped carbon dioxide emissions fleet-wide at 171 grams per mile for model year 2026, potentially translating to a fuel economy value of as much as 38 mpg in real-world conditions.
Still, that’s far from Biden’s own goal for half of U.S.
The mandates, which will take effect in 60 days and govern passenger cars, SUVs and light trucks from model years 2023 through 2026, represent the toughest-ever standards of the kind.
Although environmentalists and administration officials had warned those provisions risked undercutting actual, real-world emissions reductions, automakers stressed the flexibilities are vital to meeting the new standards.
For model year 2023, the EPA is requiring a combined fleet-wide average of 202 grams of carbon dioxide per mile — a 9.8% increase in stringency over the relaxed Trump-era standards for model year 2022.
The updated standards set the stage for another tranche of auto standards governing multiple pollutants for model year 2027 and beyond.
The new requirements “improve emissions cuts too slowly and extend key loopholes,” said Dan Becker, director of the Center for Biological Diversity’s Safe Climate Transport Campaign.
The EPA estimated the new requirements would yield $190 billion in net benefits tied to public health improvements, gasoline savings and avoided emissions — some 3 billion tons worth through 2050.