Environmental Groups Sue Over U.S. Vehicle MPG Rollback

Several environmental organizations filed a Friday court challenge seeking review of the Trump administration’s revised vehicle-efficiency requirements. The petition, brought against Transportation Secretary Sean Duffy and National Highway Traffic Safety Administration chief Jonathan Morrison, argues that the changes will increase gasoline use, motorists’ fuel expenses and vehicle emissions.

Announced Monday, the revised Corporate Average Fuel Economy rules require automakers’ fleets to average 34.9 miles per gallon in 2031. The earlier requirements projected a 50.4-mpg average. The Department of Transportation says the change will reduce a new vehicle’s average initial price by $1,300, lower yearly oil use and provide manufacturers with greater freedom over the vehicles they build.

The plaintiffs dispute those benefits, maintaining that reduced efficiency will cost drivers more and worsen emissions tied to climate change. Environmental Protection Agency figures put yearly carbon dioxide output from an ordinary passenger vehicle at 4.6 metric tons. Transportation generated 28% of U.S. greenhouse gas emissions in 2022, the latest year cited.

For Simi Valley households and commuters, the case concerns both driving costs and vehicle pollution. Friday’s nationwide gasoline average was $4.40 per gallon, compared with $3.16 one year earlier and about $2.98 shortly before the Iran war began in late February. The legal challenge will now proceed through the U.S. Court of Appeals.