Technology – E85 Biofuels

5 05 2009

E85 – Wikipedia, the free encyclopedia

There are questions about the use of bio fuels like E85, ostensibly to reduce carbon emissions, when they may have a large carbon footprint according to one study. This topic is currently under debate.

Their commitment

For the 2009 automobile year, General Motors will offer 23 different engine/model flex-fuel vehicle combination.Ford Motor company offers eight models, Chrysler will offer 11 models,and Toyota will offer just two.

In US, Honda does not offer any E85 powered flex fuel vehicles in 2009.

GM has stated a commitment to dedicate 50% of its production to Flex-Fuel E85 capable vehicles by the 2012 model year.

As of 2008, there were an estimated 7 million Flex-Fuel capable vehicles on the road in the United States. A recent GM study found that roughly 70 percent of its flex-fuel vehicle owners did not know they could use E85, and fewer than 10 percent did so


E85 consumes more fuel in flex fuel type vehicles when the vehicle uses the same compression for both E85 and gasoline because of its lower fuel ratio and lower heating value. European car maker Saab currently produces a flex fuel version of their 9five sedan which consumes the same amount of fuel whether running e85 or gasoline,though it is not available in the United States. So in order to save money at the pump with current flex fuel vehicles available in the United States the price of E85 must be much lower than gasoline. Currently E85 is about 5-10% less expensive in most areas. More than 20 fueling stations across the Midwest are selling E85 at the same price as gasoline. E85 also gets less MPG, at least in flex fuel vehicles. In one test, a Chevy Tahoe flex-fuel vehicle averaged 18 MPG [U.S. gallons] for gasoline, and 13 MPG for E85, or 28% fewer MPG than gasoline. In that test, the cost of gas averaged $3.42, while the cost for E85 averaged $3.09, or 90% the cost of gasoline.

Environmental Impact

The initial assumption that biofuels were good for the environment because they had a smaller carbon footprint is in debate because some claim that the production of grain alcohol, and therefore E85, may actually have a greater environmental impact than fossil fuel.

That view says that one must consider:

  • The forest land cleared for the additional corn (or other source of alcohol); allowing trees to grow on the land would have locked up more carbon.
  • The huge carbon footprint of the agricultural machinery run to plant and harvest, and to spread chemicals in between.
  • The environmental impact of those chemicals themselves, including fertilizers and pesticides necessary for efficient mass-production of the grains used.
  • The larger amount of energy required to ship and process the grains and turn them into alcohol, versus the more efficient process of converting oil into gasoline or diesel.
  • Even resources such as water, needed in huge amounts for grain production, can have serious environmental impact, including ground water depletion, pollution runoff, and algae blooms from waste runoff

Others say that Ethanol from corn, as a fuel available now, and cellulostic ethanol in the future, both are much better fuels for the environment.Ethanol produced today 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.



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