The Trump administration has finalized Corporate Average Fuel Economy standards requiring a combined fleetwide average of roughly 34.9 miles per gallon for passenger cars and light trucks in the 2031 model year, down from the 50.4 mpg projected under Biden-era rules. The target is above the 30.1 mpg average for model-year 2024 vehicles but close to the roughly 34.5 mpg level NHTSA projected in December. The Transportation Department says the rule will lower the average cost of a new vehicle by $1,300 and save Americans $138 billion over five years, while its earlier analysis projected $60.6 billion in lower automaker technology costs through 2031. The rule also ends trading of newly earned compliance credits after model year 2027 and reduces annual efficiency increases. Automakers and industry groups welcomed the changes as better aligned with consumer demand and market conditions. Environmental groups said weaker requirements would increase gasoline use, carbon dioxide emissions and local air pollution, and the Sierra Club said it would fight the rule. The rollback comes as gasoline averaged $4.47 a gallon Monday, compared with $3.13 a year earlier, amid disruption to global fuel supplies from the war in Iran.