Lower-Cost, Lower-Emissions Bioethanol

What Is E15?

E15, most commonly sold as Unleaded 88 (UNL88) by fuel retailers, is a fuel blend made of gasoline and 15% American ethanol. Higher in octane than standard fuel grades, it burns cleaner and cooler than standard gasoline and can be used in 96% of the vehicles on the road today (all cars 2001 or newer). It also costs less on average than other fuel options.

Why Isn’t E15 Sold Year-Round Today?

Fuel – like any liquid – evaporates more quickly in warmer weather, and when it does evaporate, it can contribute to the creation of smog-forming emissions. That is why limits on evaporate emissions, or Reid Vapor Pressure (RVP), are more stringent during the summer months. But those regulations were crafted more than 20 years before EPA approved the use of E15. In an amendment to the Clean Air Act in 1990, Congress specified that fuel with 10% ethanol (E10 or regular) could be sold year-round to encourage the use ethanol-blended fuels, which provide significant reductions in tailpipe and carbon emissions.

However, the RVP waiver that Congress granted, E10 was never extended to higher blends – despite E15 being a cleaner fuel with lower evaporative emissions.

Regulatory & Legal Milestones
1990 – Congress imposes RVP limits, but grants an RVP waiver for E10
2009 – E15 waiver filed with EPA
2011 – EPA approves E15 for 2001 and newer cars
2019 – EPA extends RVP waiver to include E15; AFPM challenges EPA rule
2021 – D.C. Circuit ruling reverses EPA’s waiver extension for E15
2022-24 – EPA allows year-round E15 on emergency basis
2025 – State opt-outs to take effect in eight Midwestern states

Learn more about the importance of ensuring year-round sales of E15.

How Is Growth Energy Working to Increase Access to Higher Blends Like E15 at the State Level?

• Growth Energy supports a number of state-level efforts to increase and incentivize the use of E15. Most recently, Growth Energy supported the successful enactment of E15 standards in Nebraska and Iowa. In 2024, Nebraska became the first state to include E15 as a fuel offering at new or updated retail stores and in 2025, Iowa will also have the higher blend fuel option at retailers throughout the state.
• We’ve also worked with state legislators to enact tax incentives for retailers that encourage the sale of more E15. E15 tax incentives have currently been enacted in Illinois, Iowa, Missouri, Nebraska, and South Dakota. Growth Energy has advocated for similar incentives in Indiana, Kansas, Michigan, Ohio, and Wisconsin.
• Growth Energy continues to advocate for regulatory approval for E15 in California.
• Our state policy and market development teams continue to work with state agencies toward establishing or amending regulatory frameworks that remove limitations and barriers to offering and advertising E15.
• Growth Energy also endorsed the efforts of midwestern governors and attorneys general to opt out of the federal RVP rules that limited the year-round sale of E15. In February 2025, the Environmental Protection Agency (EPA) approved the petitions of Iowa, Nebraska, Illinois, Minnesota, Missouri, Ohio, South Dakota, and Wisconsin to opt out and will be permitted to apply the same regulations to E15 that they currently apply to standard gasoline (E10) starting in 2025.

What Changes Need to Be Made to American Infrastructure to Expand Access to Biofuels?

First, EPA should put our existing infrastructure to better use by allowing fuel retailers to use their current storage and dispensing equipment for E15, rather than just for E10. The agency must also simplify its labeling requirements, so that these rules don’t drive retailers away from selling E15 just because of the administrative burden.

Second, in the Inflation Reduction Act (IRA), Congress provided $500 million to support the development of biofuels infrastructure, including infrastructure improvements for blending, storing, supplying, or distributing. This funding is vital to expanding the availability of lower-cost, lower-carbon E15 across the country to help retailers make infrastructure changes to offer E15.

What Impact Would a Nationwide Shift to E15 Have?

• If the United States transitioned from E10 to E15 nationwide, greenhouse gas emissions would fall by 17.62 million tons per year, the equivalent of removing approximately 3.85 million vehicles from the road.
• Nationwide adoption of E15 would save consumers $20.6 billion in annual fuel costs, put an additional $36.3 billion in income into the pockets of American households, support an additional 188,000 jobs, and generate $66.3 billion for the U.S. GDP.

What Impact Would Growth Energy’s Policy Priorities Have on Consumers, the Economy, or the Environment?

• Year-round E15 would save drivers money. Consumers choosing E15 experienced average cost savings of 10-30 cents per gallon, with some locations offering over $1 off per gallon.
• Increased use of E15 would reduce smog-forming pollutants and lower emissions of particulate matter up to 50 percent compared to gasoline.