Alternative Fuels: Design for one or more fuels

Single fuel vehicles (SFV):.Alternative SFVs are designed to operate with one fuel that is other than gasoline or diesel.

Flex-fuel vehicles (FFV): FFVs are constructed with a single drive system and single fuel tank, but the engine may operate on different fuels. FFVs provide options for operation with a choice of fuels, depending on what is available. Some examples of pairs of fuels currently used in FFVs are [1-2]:

  1. Pure unleaded gasoline or a mixture of unleaded gasoline and alcohol: E85 (85% ethanol with gasoline) or M85 (85% methanol with gasoline).
  2. Diesel and bio-diesel: Current research is exploring 5-20% bio-diesel mixed with standard diesel [3].

FFVs are now common in Brazil after decades of government subsidy for the development of ethanol as a vehicle fuel. Last year over one million FFVs were sold in Brazil (70% of the market) that were designed to run on a blend of 22% ethanol/78% gasoline, or nearly pure ethanol [4].

Bi-fuel vehicles (BFV): BFVs have two separate fuel systems (storage tanks) with the capability of drawing from one or the other. Some examples of fuel combinations in current BFVs are:

References

  1. Alternative Fuels Data Center, US Department of Energy,
    http://www.eere.energy.gov/afdc/, January 2006.
  2. Department of Energy Vehicle Buyer’s Guide for Consumers,
    http://www.eere.energy.gov/cleancities/vbg/consumers/, January 2006.
  3. Alexander, D., “Fuel for Thought,” Automotive Engineering, Society of Automotive Engineers, September 2005.
  4. Press Release, Bosch, January 2006.