Ethanol has been widely used throughout the Midwestern United States for many years. Legislation creating a Renewable Fuels Standard and the need for octane have prompted the expansion of ethanol blended fuels to new markets across the country. As a result, ethanol is blended in virtually every gallon of unleaded gasoline in the U.S.

Ensuring Quality and Good Marketing Practices with Ethanol Blends

This presentation describes historical ethanol use and provides background information on ethanol blended fuels as ethanol specifications, ASTM Standards and ethanol as a fuel and fuel additive. Providing high quality fuels to consumers is the goal of every fuel manufacturer. Widely used specifications for transportation fuels are available from ASTM International.

System Preparations and Post Blending Maintenance: Tanks, Filters, Water

This presentation focuses on the necessary steps for successful introduction of ethanol or ethanol blended fuels to a new or existing fuel distribution system.  Before introducing ethanol into a new storage and transfer system or during the process of converting an existing system to handle ethanol or ethanol blended fuels, a thorough system evaluation should be conducted to ensure appropriate components and safety equipment have been selected and installed. This evaluation should include training of employees and personnel as well as review of safety and regulatory precautions. Just as with gasoline, there are many regulatory considerations that also must be investigated when offering ethanol blended fuels.

Phase Separation

Ethanol has infinite solubility with water, a major chemical difference from gasoline. With appropriate system overview and conversion procedures, water concerns can be complete mitigated. The following presentation contains information about proper procedures to prevent phase separation.

Transportation and Safety

Safety must be the number one goal when handling, transporting, and distributing transportation fuels, including ethanol. First responders and transportation personnel should be familiar and well prepared for ethanol emergencies. Important safety information can be found in this presentation.

Converting to Ethanol Blended Fuels?

The RFA has developed an extensive checklist to assist retail stations wanting to offer ethanol blended fuels. The key to a smooth and seamless transition is a thorough investigation and implementation plan. This checklist hopes to provide essential step by step information to help ensure a successful transition. To view this checklist, please click here.

Fuel Economy

Determining the exact cause of reductions in fuel economy is not as easy as it seems. Fuel Economy is the comparison of engine performance in distance terms with energy usage (miles per gallon), and it is influenced by many different factors, including excess cargo weight, vehicle condition and maintenance, proper tire inflation, use of air conditioning, consumer driving habits, climate related effects, and fuel composition. These factors produce similar and in most cases greater reductions in fuel economy than the use of 10% ethanol in gasoline. This document includes additional information on fuel economy.

Moving beyond E10…

Passage of the 2007 Energy Independence and Security Act (EISA) was a step closer to help encourage the use of ethanol beyond the traditional 10% (E10) blend for conventional vehicles. With expanded ethanol use and expectations for improved vehicle fuel economy, the U.S. can dramatically reduce demand for gasoline and increasingly displace our need for oil and gasoline imports.

Currently, the U.S. Environmental Protection Agency (EPA) recognizes gasoline blended with 10% ethanol as an acceptable fuel for use in today’s gasoline-only vehicle fleet. The EPA had approved the use of E15 (15% ethanol) in model year 2001 and newer cars, light-duty trucks, medium-duty passenger vehicles (SUVs), and all flex-fuel vehicles (FFVs) through a second partial waiver granted in January 2011, but the fuel must first be registered before entering the marketplace. The commitment of auto manufacturers to make increasingly more flex-fuel vehicles (FFVs) available (vehicles that are capable of operating on 85% ethanol (E85), 100% gasoline, or any mixture of the two) will complement the increased use of ethanol blended fuels. By looking at the use of higher ethanol content in gasoline for conventionally fueled vehicles, we can help reach our nation’s goals of energy independence. Many authoritative entities, such as the RFA, State of Minnesota, and Department of Energy, are focused on investigating the effect of higher levels of ethanol content in gasoline and the suitable use by conventional engine platforms.

State of Minnesota and RFA

Minnesota passed a state law requiring that ethanol comprise 20% of all gasoline sold in the state beginning in 2013. The two ways to accomplish this would be for a dramatic increase in E85 fuel sales or to include a higher ethanol content in gasoline, beyond the traditional 10%. In order to move forward with the use of higher level blends of ethanol, a variety of vehicle suitability tests must be conducted. To address these concerns, the RFA partnered with the State of Minnesota on a year-long study of the effect and performance of gasoline blends containing 20% ethanol (E20) on today’s vehicle engines and engine components. This initial study included materials compatibility, drivability and emissions testing. The study found no evidence that E20 would adversely impact technologies commonly found in vehicles on American roads today. Click here to learn more.

U.S. Department of Energy

Through various initiatives, the Department of Energy (DOE) works with industry to develop and deploy advanced transportation technologies that reduce the nation’s use of imported oil and improve air quality. In support of these goals, DOE initiated a test program to evaluate the potential impacts of intermediate ethanol blends on legacy vehicles and other engines. The first effort culminated in a research report titled, “Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road Engines,” released in October 2008 and updated in February 2009. The test program focuses specifically on the effects of intermediate blends of E15 and E20 on emissions, catalyst and engine durability, drivability or operability, and materials compatibility.This report, the first in a series of peer-reviewed reports summarizing the results of intermediate ethanol blends, provides explicit details on the engine operation and performance for sixteen popular late-model vehicles and 28 small non-road engines, including lawn equipment and generators.

Vehicle results include the following when E15 and E20 were compared with traditional gasoline:

  • Fuel economy was commensurate with energy density,
  • Regulated tailpipe emissions remained largely unaffected,
  • Under normal operations, catalyst temperatures in the cars were cooler or unchanged; and,
  • Based on informal observations during testing, drivability was unchanged.

The tests conducted on small engines focused on identifying emissions or operational issues and the measurement of several key engine temperatures. They measured emissions and temperatures at various stages of the engines’ lives—when new, at half life, and at full life. The primary focus of these tests was to assess any operational problems and to evaluate how engine operation and emissions change over time with exposure to various levels of ethanol. The small non-road engine results include the following:

  • As ethanol content increased, the closed loop engines operated leaner causing:
    • Decreased regulated emissions, CO and HC; Increased NOx,
    • Engine and exhaust temperatures generally increased;
  • Commercial engines, as well as more sophisticated residential engines, exhibited no particular sensitivity to ethanol from a durability perspective; and,
  • The effect of E15 and E20 on the durability of smaller, less expensive residential engines (e.g., line trimmers) was not clear given that a number of these engines failed regardless of fuel type.


The RFA is committed to working with its partners, including, U.S. DOE, the State of Minnesota, trade groups, and importantly the auto and small engine communities to ensure the data on materials compatibility, drivability, durability and emissions supports the effort to move beyond traditional blends of ten percent ethanol in conventional vehicles.