The United States Environmental Protection Agency announced on Friday it will finalize rules regulating fuel efficiency standards for vehicles through 2025, keeping in place a policy that was believed to be at risk of repeal under the incoming Donald Trump administration.

The policy will mandate automakers produce cars that offer at least 51.4 miles per gallon equivalent (mpg-e) by 2025. The mpg-e measurement is used by the EPA to compare the energy consumption of alternative fuel vehicles like electric cars to vehicles with the fuel economy of conventional vehicles.

Translated, the goal of 51.4 mpg-e works out to about 36 miles per gallon in real world fuel consumption. Reaching that level would raise the industry average for fuel economy by 10 degrees per mile over the next eight years.

Finalizing the rules on Friday doesn’t guarantee the Trump administration won’t be able to overturn the policy, but it does make the task considerably more challenging.

The EPA first drafted the recommendations in December, and auto manufacturers attempted to argue the agency should hold off on setting the rules in stone. They argue the standards will raise vehicle costs and accused the EPA of rushing its process—which wasn’t required to be finalized until 2018—in order to preempt any changes planned under the Trump administration.

Reversing the rules at this point would require the new EPA leadership to initiate a new rulemaking session and make changes to the current standards that were set in place back in 2012. The changes would be subject to challenge, and the EPA would have to defend in court its decision to ditch eight years of technical analysis, according to a report from Bloomberg.

Trump hasn’t taken an official policy position on fuel efficiency standards, but he has staffed his transition team with people who would likely advise him to do so.

Trump senior policy advisor John Mashburn was quoted as saying the Trump administration intended to complete “a comprehensive review of all federal regulations” including a review of the fuel economy and emissions standards to “make sure they are not harming consumers or American workers.”

Scott Pruitt, the attorney general of Oklahoma and the nominee to run the EPA during the Trump presidency, has denied the scientific consensus on human-caused climate change. He also has considerable ties to the fossil fuel industry, including an instance where he sent a letter to the EPA challenging its emissions estimates from natural gas wells in Oklahoma that turned out to have been written by Devon Energy, one of the oil and gas companies operating in the state.

Pruitt testified before the House Energy and Commerce Committee in 2013 to state his belief that the EPA had overstepped its authority and was pursuing an “anti-fossil fuel agenda.”

Both Trump and Pruitt have called for the neutering of not the complete abolishment of the EPA as a whole, so while the agency’s fuel efficiency standards may survive longer than expected, the agency itself may be in trouble.