(credit: Amy Marbach)

On Friday, the Environmental Protection Agency (EPA) announced that it had finalized the rules governing fuel efficiency for vehicles made until 2025. The rules ratchet up the fuel efficiency numbers that automakers must meet over the span of the next eight years. By 2025, automakers will have to hit an overall 51.4 mpg average efficiency rating for their fleet, which translates to about 36 mpg in real-world driving conditions—a bump of 10 mpg from what US fleets get today.

The decision comes just a week before the Trump administration takes office. President-elect Donald Trump has not commented on the EPA’s fuel efficiency guidelines, but automakers had been hoping that the EPA would delay signing off on this rule so that his administration might relax fuel efficiency standards out to 2025. Trump has denied the existence of climate change—a factor in the EPA’s fuel efficiency decisions—despite the preponderance of evidence showing that climate change is real and human-caused.

Although a Trump Administration could reverse the EPA’s new rules, doing so will be significantly harder than if the EPA had left the process for finalizing its December recommendations up to the new administration.