US finalizes weaker fuel efficiency standards, dropping 50.4 mpg target to 34.9 mpg

The US Department of Transportation has finalized new rules that significantly weaken federal fuel efficiency standards for cars and trucks. The updated requirement sets a fleet average of 34.9 miles per gallon, a sharp rollback from the Biden-era target of 50.4 mpg that had been set for model year 2031. The Trump administration described the move as one of its largest deregulatory actions to date. Officials claim the change will reduce the average vehicle purchase price by roughly $1,300. Consumer, health, and environmental groups have strongly criticized the rollback, arguing it undermines public health and climate goals.