I drive on LPG (
http://en.wikipedia.org/wiki/Liquefied_petroleum_gas). I'm very happy with it. Have an extra tank of 120 ltrs installed in my truck. By the switch of a button, I can change from regular gas to LPG. My previous truck (dodge ram) also ran on LPG. With european gas prices, it's a MUST have in a big american truck.
frenzy
Belgium