Environmental Groups Sue to Block Trump Fuel Efficiency Rollback

The Department of Transportation’s finalized rule effectively dismantles progress toward the Biden-era target of 50.4 miles per gallon by 2031. According to internal analysis from the National Highway Traffic Safety Administration, the new mandate would force the 2031 fleet below the 35.4 mpg benchmark already reached by 2024 models. Projections indicate this shift will result in 122 billion additional gallons of gasoline consumed by 2050 and approximately 1 billion metric tons of added carbon dioxide emissions.

Legal experts representing the coalition, which includes the Center for Biological Diversity, the Environmental Defense Fund, and the Sierra Club, contend that the policy will ultimately harm consumers. While the administration claims the change lowers upfront vehicle costs, the NHTSA’s own data suggests that drivers will face over $1,600 in increased lifetime fuel expenses per vehicle—far outweighing the roughly $1,300 in projected initial savings. The lawsuit seeks an immediate appeals court review to halt what petitioners describe as a dangerous reversal of long-standing environmental policy.