In 1990, Congress specified that fuel with 10% ethanol (E10) could be sold year-round to encourage the use of ethanol-blended fuels, which save consumers money and burn cleaner than fuels without ethanol. However, the waiver Congress granted for E10 predated the introduction of higher ethanol blends like E15. E15 has an even lower Reid Vapor Pressure (RVP) than E10, meaning it has lower evaporative emissions than standard E10 fuel. This means that despite having lower emissions than E10, E15 cannot be sold in most states during the summer months, except temporarily through emergency waivers.
As a result of emergency waivers and other EPA regulatory action from 2019-2025, consumers saved 10-30 cents per gallon by choosing E15, with some locations offering E15 for over $1 per gallon less than E10.
Passing legislation to allow E15 to be sold year-round would increase availability and save consumers money. If we made E15 the standard fuel in the U.S., we could save $20 billion+ in fuel costs each year.