The Trump administration announced on Monday, September 28, 2026, that it is rolling back federal fuel efficiency standards for new cars and light trucks. The new policy lowers the required average fuel economy for the national vehicle fleet to 34.9 miles per gallon by 2031. This replaces a Biden-era rule that would have required the fleet to reach an average of 50.4 miles per gallon by that same year.
The decision follows the administration's earlier repeal of Environmental Protection Agency (EPA) regulations intended to encourage a shift toward electric vehicles (EVs). President Trump stated on Truth Social that the move terminates what he described as a "ridiculous EV Mandate." The administration also noted that previous penalties for failing to meet efficiency standards had already been reduced to $0 through a provision in the "Big Beautiful Bill."
Administration officials argued the rollback will make new vehicles $1,300 cheaper on average by reducing manufacturing costs. President Trump stated the previous standards cost manufacturers billions and "forced Americans into cars they never wanted." Conversely, the Biden administration had previously estimated that its stricter 2027-2031 standards, which required a 2 percent annual efficiency increase, would have saved drivers more than $600 in fuel costs over the life of a vehicle.
The scale of the impact involves the entire national fleet of new passenger cars and light trucks manufactured for the U.S. market over the next five years. The 15.5 miles-per-gallon difference between the two sets of standards represents a significant shift in national fuel consumption projections. Environmental groups, such as the Center for Biological Diversity, stated the rollback will lead to increased pollution and health risks, while the administration maintains it is necessary to protect auto manufacturing jobs and consumer choice.
The rollback sets a precedent for how the executive branch can utilize rulemaking to reverse the climate and transportation policies of a prior administration. While the Big Beautiful Bill had already removed financial penalties for non-compliance, this formal rule change removes the legal requirement for automakers to meet the higher targets altogether. Moving forward, the domestic auto industry will no longer be legally bound to reach the 50.4 mpg average by 2031, though they may still produce efficient or electric vehicles to compete in global markets where clean car standards continue to advance.
The new standards were approved by the president and reported as effective as of Monday, September 28, 2026. Future challenges or adjustments to these figures would likely occur through new federal rulemaking or potential litigation from environmental advocates.