Check out this article I found in Science Daily
-- Alternative Fuel Vehicle refers to a vehicle that runs on a fuel other than traditional gasoline or diesel; any method of powering an engine that does not involve petroleum. Due to a combination of heavy taxes on fuel, particularly in Europe, tightening environmental laws, particularly in California, and the possibility of further restrictions on greenhouse gas emissions, work on alternative power systems for vehicles has become a high priority for governments and vehicle manufacturers around ...
