The Trump administration rolled back federal fuel economy standards for light-duty vehicles. The National Highway Traffic Safety Administration lowered the required average fuel efficiency from 50.4 miles per gallon by 2031 to 34.9 mpg, according to the final rule released today.
Connecticut officials opposed the rollback. Governor Ned Lamont said the action means "Americans will see more trips to the gas station, more profits for big oil, dirtier air, and less efficient vehicles." Acting Commissioner Emma Cimino of the Connecticut Department of Energy and Environmental Protection said the rollback eliminates $82 billion in projected savings for consumers at the pump.
According to the federal agency's regulatory analysis, the final rule will raise fuel costs for consumers by $1,600 per vehicle and create over $345 billion in additional costs through 2050. The rollback is projected to result in the loss of over 10,000 jobs by model year 2031, increase fuel consumption by 121 billion gallons, and increase greenhouse gas emissions by over 1,300 million metric tons of carbon dioxide equivalent.
Federal fuel economy standards have saved households $630 to $840 annually over the last 10 years, according to Connecticut officials. Connecticut has more than 2.7 million vehicles registered. Cars and trucks account for nearly 70 percent of smog-forming emissions in Connecticut and approximately 35 percent of its climate pollution. Air quality in Connecticut exceeded federal health-based ozone standards on 23 days in 2024, 22 days in 2025, and 17 days so far in 2026.