• E10 and E15 are blends of ethanol and gasoline—the number after the “E” indicates the percentage of ethanol.
  • Most of the gasoline sold in the U.S. contains up to 10% ethanol—the amount varies by region—and all auto manufacturers approve blends up to E10 in their gasoline vehicles.
  • Vehicles will typically go 3% to 4% fewer miles per gallon on E10 and 4% to 5% fewer on E15 than on 100% gasoline.3