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What is Ethanol?


Ethanol (ethyl alcohol) is an alternative fuel fermented from corn, grains or agricultural waste or it is chemically extracted from ethylene (hydration). It is used primarily as a supplement to gasoline.

Pure ethanol is not sold as a stand-alone fuel, at least not yet—it is commonly mixed with gasoline in varying percentages creating a transitional fuel that will pave the way for pure alcohol vehicles. For example, E85 is a common mixture: 85 percent ethanol, 15 percent gasoline. Most pump gasoline contains ethanol in much lower percentages. In the United States, it is added to gasoline in varying quantities (most commonly 10 percent) to boost the octane level and meet EPA requirements for oxygenated (smog reducing) fuels, especially in metropolitan areas.

To burn high concentrations such as E85, vehicles have to be designed as flex-fuel vehicles (FFVs) to utilize the unique combustion characteristics and tolerate the corrosiveness of the alcohol.

Pros: A Yes Vote

  • Clean burning fuel: Reduces ozone-forming emissions.
  • Renewable: It’s plant based, therefore what is used can be re-grown.
  • Support of local agriculture: Produced domestically, it’s one more way to support local farmers.

Cons: What to be Aware of

  • Corrosive: Tends to deteriorate non-synthetic and natural rubber fuel system parts.
  • Land and labor viability: Large amounts of farmland and labor are required to grow the crops.
  • Lower energy content than gasoline: Gasoline contains about 114,000 BTUs per gallon versus ethanol's 76,000 BTUs per gallon. This equates into reduced fuel mileage depending upon the fuel mixture percentage.

    Handling & Safety

    Since ethanol is less volatile than gasoline, there’s a reduced chance of explosion in spills and accidents. Although it is more corrosive than gasoline, it is less toxic.


    The future looks good for ethanol. Not only are many ethanol refineries in the planning stages or under construction, ethanol blends (E85, E10) are becoming easier to obtain. Plus, it's fairly simple to implement into your life: With a flex-fuel vehicle and a local fueling station, you can just fill up and drive away. Check out how the cost of E85 compares.

    Learn More: Ethanol 101

    Find a Flex-fuel Vehicle

    The Alternative Fuel Bible: Find Answers to Your Fuel & Vehicle Questions

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