Fuel Choice and Deregulation Act of 2025

This bill makes it easier to use and produce alternative fuels. It lets people convert older cars to run on alternative fuels without it counting as “tampering,” as long as the conversion is well-matched to the vehicle, installed correctly, and doesn’t make emissions worse. The installer must add a label saying the car was converted after its first sale, and the EPA can still stop any kit that hurts emission performance . It also says the EPA cannot ban or control “biomass fuel” under the Clean Air Act .

For automakers, the bill changes fuel economy rules. If a manufacturer meets federal fuel economy standards, its vehicles are treated as meeting EPA greenhouse gas rules, too. These manufacturers also get an 8 miles-per-gallon boost added to their average fuel economy calculation, and they can carry forward extra credits for up to five years. These changes would apply starting with model year 2026 and later .

• Who is affected: car owners and mechanics doing conversions; biomass fuel producers; automakers that build fuel-choice vehicles fileciteturn0file2turn0file1
• What changes:
  • Converting older cars to alternative fuels is allowed if it doesn’t worsen emissions and is properly done; labeling is required; EPA can still block harmful kits
  • EPA may not prohibit or control biomass fuel under the Clean Air Act
  • Automakers get compliance credit with EPA greenhouse gas rules, an 8 mpg bonus in calculations, and more flexible credit use
• When: automaker fuel economy changes start with model year 2026; other changes take effect as the bill directs in its amendments fileciteturn0file1turn0file2