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E15: Frequently Asked Questions

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What is E15?

E15 is a blend of gasoline and up to 15 vol% ethanol. Prior to EPA's October waiver decision, the amount of ethanol in motor vehicle gasoline was limited to 10 vol% (E10). E10 was granted a waiver under Clean Air Act section 211(f)(4) more than 30 years ago and is now ubiquitous in the marketplace, making up over 90% of the U.S. gasoline market.

The primary source of ethanol is corn, but other grains or biomass sources may be used as feedstocks.

What Vehicles May Use E15?

  • Flexible-fuel vehicles (FFVs)
  • MY2001 and newer cars
  • MY2001 and newer light-duty trucks
  • MY2001 and newer medium-duty passenger vehicles (SUVs)

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What Vehicles and Engines May Not Use E15?

  • All motorcycles
  • All vehicles with heavy-duty engines, such as school buses, transit buses, and delivery trucks
  • All off-road vehicles, such as boats and snowmobiles
  • All engines in off-road equipment, such as lawnmowers and chain saws
  • All MY2000 and older cars, light-duty trucks, and medium-duty passenger vehicles (SUVs)

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What is the E15 Waiver?

In order to protect the emission control systems of vehicles and engines, the Clean Air Act prohibits the introduction into commerce of fuels or fuel additives that are not substantially similar to the fuels or fuel additives used in certifying vehicles and engines to emission standards. However, the Clean Air Act authorizes EPA to grant a waiver of this prohibition if it can be demonstrated that the vehicles and engines using the otherwise prohibited fuel or fuel additive will continue to meet their emission standards over their “full useful life” (e.g., 100,000 or 120,000 miles for light-duty motor vehicles, depending on the vehicle type and model year).

In March 2009, Growth Energy (a coalition of U.S. ethanol supporters) and 54 ethanol manufacturers applied for a waiver to increase the allowable amount of ethanol in gasoline from E10 to E15. The waiver application included data on the impact of E15 on vehicle emissions, fuel system materials, and driveability. Additional data were developed by DOE, which in 2008 began testing for potential impacts of various ethanol-gasoline blends on the emission control systems of MY2007 and newer light-duty motor vehicles. This testing followed enactment of the Energy Independence and Security Act of 2007, which calls for significantly increasing the amount of biofuels, such as ethanol, to be used in transportation fuel.

On October 13, 2010, based in large part on DOE test data, EPA partially granted Growth Energy's waiver request. This partial waiver allows fuel and fuel additive manufacturers to introduce E15 into commerce for use in MY2007 and newer light-duty motor vehicles, subject to certain conditions. EPA denied the waiver for E15 use in MY2000 and older light-duty motor vehicles, and all heavy-duty gasoline engines and vehicles (e.g., delivery trucks), highway and off-highway motorcycles, and nonroad engines, vehicles, and equipment (e.g., boats, snowmobiles, and lawnmowers) due to insufficient test data or other information to support a waiver for these vehicles and engines.

On January 21, 2011, after additional DOE test data were made available to the public (see EPA Docket #EPA-HQ-OAR-2009-0211 at www.regulations.gov), EPA took further action on Growth Energy’s waiver request application by partially approving the waiver to allow the introduction into commerce of E15 for use in MY2001-2006 and newer light-duty motor vehicles, subject to the same conditions that apply to the partial waiver decision for MY2007 and newer light-duty motor vehicles. Taken together, the two waiver decisions allow the introduction into commerce of E15 for use in MY2001 and newer light-duty motor vehicles if the waiver conditions are met.

On February 27, 2012, EPA issued a memorandum (PDF) (6 pp, 2.4MB, February 27, 2012) concerning a minor technical error related to one of the DOE test vehicles from MY2001-2006. The error stemmed from a manufacturer's mislabeling of the test vehicle model and had no material impact on the January 2011 waiver decision. A fact sheet about the memorandum is available here.

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What Conditions are Part of the Waiver Decision?

EPA placed two types of conditions on the waiver for E15: those to help prevent misfueling of E15 into vehicles, engines and equipment that may not use E15 and those addressing fuel and ethanol quality. All conditions must be met before E15 may be introduced into commerce.

Fuel quality conditions:

  • Ethanol used for E15 must meet ASTM International D4806-10.
  • The Reid Vapor Pressure for E15 is limited to 9.0 psi during the summertime.

Misfueling mitigation conditions:

  • Labels must be placed on E15 retail dispensers indicating that E15 use is only for MY2001 and newer motor vehicles.
  • Product Transfer Documents (PTDs) must accompany all transfers of fuels for E15 use.
  • Parties involved in the manufacture of E15 must participate in a survey of compliance at fuel retail dispensing facilities to ensure proper labeling of dispensers.
  • Parties must submit a plan addressing conditions to EPA for approval (see here).

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What is EPA doing to Address Potential Misfueling?

On June 23, 2011, EPA finalized regulations to help prevent misfueling of vehicles, engines and equipment not covered by the partial waiver decisions. These regulations require all E15 fuel dispensers to have a label, shown below, that informs consumers about what vehicles can, and what vehicles and equipment cannot, use E15. The rule prohibits the use of gasoline containing greater than 10 vol% ethanol in the vehicles, engines and equipment that cannot use E15. The rule also requires PTDs specifying ethanol content and Reid Vapor Pressure (RVP) to accompany the transfer of gasoline blended with ethanol and a survey of retail stations to help ensure compliance with labeling and ethanol content requirements.

The label on E15 fuel dispensers to inform consumers about the appropriate use of E15.  E15, up to 15% ethanol, is for use only in 2001 and newer passenger vehicles and flex-fuel vehicles.  Do not use E15 in other vehicles, boats, or gasoline-powered equipment.  It may cause damage and is prohibited by federal law.

This rule complements the E15 partial waiver decisions, and does not replace or remove any conditions of the waiver decisions. The rule is expected to facilitate effective implementation of the waiver conditions and further reduce the potential for misfueling.

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If you have questions or request information, please contact the appropriate support or help line found on the Support & Help page.

Please visit EPA's Transportation and Air Quality web-based repository of mobile source documents, Document Index System (DIS). This searchable repository contains regulations, Federal Register notices, policy letters, and guidance documents.

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