[ax0n]

Most ICE's will run on pretty much anything as long as you nail stoichiometry and it burns at approximately the same speed as the hydrocarbon chains found in gasoline. It's actually pretty trivial to retrofit a normal car to run on liquid propane or natural gas. You can even run them directly on hydrogen gas, but pure hydrogen's far too volatile to be dragging around in a passenger vehicle. Interested to see where it's going.

[jacquesm]

Here is a car running on wood with a woodgas convertor:

http://www.langsdemaas.nl/hetvervoer/geefgas1.jpg

During the war years and the recovery period immediately afterwards gasoline was so scarce in Europe that this was a fairly common occurrence.