Ethanol Myths & Facts

Source: U.S. Department of Energy, Energy Efficiency and Renewable Energy April 15, 2010

Ethanol is a clean, renewable fuel. It is helping to reduce our nation’s dependence on oil and offers a variety of economic and environmental benefits. As we look to broaden our domestic energy resources, common misconceptions about ethanol production and use need to be cleared up. This page addresses some of the common myths about ethanol.

MYTH: In terms of emissions, ethanol pollutes the same as gasoline or more.
FACT: Ethanol results in fewer greenhouse gas (GHG) emissions than gasoline and is fully biodegradable, unlike some fuel additives.

  • Today, on a life cycle basis, ethanol produced from corn results in about a 20 percent reduction in GHG emissions relative to gasoline. With improved efficiency and use of renewable energy, this reduction could be as much as 52 percent.
  • In the future, ethanol produced from cellulose has the potential to cut life cycle GHG emissions by up to 86 percent relative to gasoline.
  • Ethanol blended fuels currently in the market – whether E10 or E85 – meet stringent tailpipe emission standards.
  • Ethanol readily biodegrades without harm to the environment, and is a safe, high-performance replacement for fuel additives such as MTBE.

MYTH: More energy goes into producing ethanol than it delivers as a fuel.
FACT: In terms of fossil energy, each gallon of ethanol produced from corn today delivers one third or more energy than is used to produce it.

  • Ethanol has a positive energy balance – that is, the energy content of ethanol is greater than the fossil energy used to produce it – and this balance is constantly improving with new technologies.
  • Over the last 20 years, the amount of energy needed to produce ethanol from corn has significantly decreased because of improved farming techniques, more efficient use of fertilizers and pesticides, higher-yielding crops, and more energy-efficient conversion technology.
  • Most studies that claim a negative energy balance for ethanol fail to take into account the energy contained in the co-products.

MYTH: Ethanol-gasoline blends can lower fuel economy and may harm your engine.
FACT: Ethanol blends in use today have little impact on fuel economy or vehicle performance.

  • While ethanol delivers less energy than gasoline on a gallon-for-gallon basis, today’s vehicles are designed to run on gasoline blended with small amounts of ethanol (10 percent or less) with no perceptible effect on fuel economy.
  • Flex-fuel vehicles designed to run on higher ethanol blends (E85 or 85 percent ethanol) do experience reduced miles per gallon, but show a significant gain in horsepower.
  • As a high-octane fuel additive and substitute for MTBE, ethanol enhances engine performance and adds oxygen to meet requirements for reformulated gasoline.