Evaluating Ethanol as a Car Fuel
  • Ethanol was used as a petrol extender during WWII (and more recently) in concentrations of 10-20%.
  • During the 1970s and 1980s Brazil used pure ethanol as the major fuel for cars. Sugar cane was grown specifically for this purpose and engines were modified accordingly. The program was subsidised by the government, and was designed to address a trade imbalance and reduce the consumption of non-renewable fossil fuels. The program was initially very successful that by mid 1980s 94% of new vehicles ran exclusively on ethanol. However the use of ethanol was challenged in the 1990s by lower oil prices and the use of ethanol was eventually phased out. A resurgence though, in recent years following record oil prices and the release of 'flex-fuel' cars in 2003. In Brazil, ethanol fuel is currently cheaper than petrol.
  • Ethanol is currently used as a fuel additive in many Brazilian cars. 30% of Brazilian cars use a fuel blend containing 25% ethanol. This is more cost effective and improves octane rating and the higher point is easily met due to higher temperatures in Brzil. However car modifications are still required to use such high percentages of ethanol.
  • Ethanol is used in USA (pasahol) and Canada (where ethanol is required by law to be added to fuels) at approximately 10% with some success as it doesn't require engine modifications and improves octane rating. However in colder states, some cars have trouble starting (due to ethanol's higher flash point) and it has been criticised for consuming food crop.
  • In Australia, governments are encouraging 10% ethanol blends such as E10 by providing subsidies for petrol suppliers that use it. Despite this, ethanol still costs more to produce.
  • There is some question as to whether using ethanol as a fuel additive at 10% still causes engine corrosion.

In conclusion:
The use of ethanol as a fuel extender seen currently has been reasonably successful, particularly in Brazil where it has reduced the nation's dependency on fossil fuels.