The U.S. Environmental Protection Agency (EPA) defines E15 as gasoline blended with 10.5% to 15% ethanol. In 2011, EPA approved E15 for use in light-duty conventional vehicles of model year 2001 and newer, through a Clean Air Act waiver request, based on significant testing and research funded by the U.S. Department of Energy. Stations are not required to sell E15, but some have started offering E15 due to state and federal incentives for upgrading equipment and better profit margins when compared with regular gasoline. E15 is available in 31 states at just over 3,000 stations. E10 remains the limit for passenger vehicles older than model year 2001 and for other non-road and small engines and vehicles that use gasoline, such as lawn mowers, motorcycles, and boats.

Vehicles approved for E15 use:
  • Flexible fuel vehicles
  • Conventional vehicles of model year 2001 and newer.
Vehicles prohibited from using E15:
  • All motorcycles
  • All vehicles with heavy-duty engines, such as school buses and delivery trucks
  • All off-road vehicles, such as boats and snowmobiles
  • All engines in off-road equipment, such as chain saws and gasoline lawn mowers
  • All conventional vehicles older than model year 2001.

There are additional regulations for stations selling blends above E10. For more information, visit the Codes, Standards, and Safety page.

Regulations to reduce evaporative emissions that can contribute to ground-level ozone impact the ability to sell E15 during the summer ozone season in parts of the country without a Reformulated Gasoline program. These regulations were established prior to E15 entering the market. The EPA issued emergency fuel waivers that allowed E15 to be sold during the summers of 2022 and 2023 in response to events that impacted petroleum markets.