Alternative Fuel Vehicles
 

Wood gas vehicles were used in Germany, Finland, Sweden and Switzerland during World War II.

http://www.lowtechmagazine.com/2010/...-gas-cars.html

If you search back, there was a discussion on this with some info. Although it might have been one of the previous boards.

Yep, lots of info about this around:

http://en.wikipedia.org/wiki/Wood_gas_generator
http://www.woodgas.net/files/FOA%2072.pdf

The good thing about it is that the vehicle's engine doesn't need to be modified much, as long as the gas generator is set up right. IMO, a lot of locations would use these for power generation, light industry and possibly transport. Also very likely for rear-area military vehicles.