Propane AutoGas is simply liquid petroleum gas, or propane, labeled for use in on-road vehicles. Propane AutoGas is the third most popular automotive fuel in the world,behind gasoline and diesel, with more than 23 million vehicles powered using Propane AutoGas around the world. Propane Autogas vehicles burn cleanly and can run at higher compression ratios than conventional vehicles. This results in higher energy output, while producing lower emissions levels.
Gasoline powered engines can be converted to use AutoGas in place of gasoline or in conjunction with it. AutoGas has an effective octane rating between 104 and 112, and it performs similarly to gasoline in an engine with no knocking. Diesel engines can replace a portion of their diesel use with propane in a dual-fuel setup, but since propane does not easily ignite from compression like diesel fuel, it cannot entirely replace diesel fuel in a diesel engine.