Liquefied petroleum gas (LPG), also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles.is a clean-burning fossil fuel that can be used to power internal combustion engines. LPG-fueled vehicles can produce significantly lower amounts of some harmful emissions and the greenhouse gas carbon dioxide (CO2). LPG is usually less expensive than gasoline, it can be used without degrading vehicle performance, and most LPG used in U.S. comes from domestic sources.

The availability of LPG-fueled light-duty passenger vehicles is currently limited. A few light-duty vehicles—mostly larger trucks and vans—can be ordered from a dealer with a prep-ready engine package and converted to use propane. Existing conventional vehicles can also be converted for LPG use. Since propane is stored as a liquid in pressurized fuel tanks rated to 300 psi, LPG conversions consist of installing a separate fuel system if the vehicle will run on both conventional fuel and LPG or a replacement fuel system for LPG-only operation.

Propane Fuel Basics

Also known as liquefied petroleum gas (LPG) or autogas, propane is a clean-burning, high-energy alternative fuel that’s been used for decades to power light-, medium- and heavy-duty propane vehicles.

Propane is a three-carbon alkane gas (C3H8). It is stored under pressure inside a tank and is a colorless, odorless liquid. As pressure is released, the liquid propane vaporizes and turns into gas that is used for combustion. An odorant, ethyl mercaptan, is added for leak detection.

Advantages of LPG

90% of propane used in U.S. comes from domestic sources.

Less expensive than gasoline.

Potentially lower toxic, carbon dioxide (CO2), carbon monoxide (CO), and nonmethane hydrocarbon (NMHC) emissions.

Disadvantages of LPG

Limited availability (a few large trucks and vans can be special ordered from manufacturers; other vehicles can be converted by certified installers).

Less readily available than gasoline & diesel.

Fewer miles on a tank of fuel.

Fuel Economy and Performance

Typically in fleet applications, propane costs less than gasoline and offers a comparable driving range to conventional fuel. Although it has a higher octane rating than gasoline rating (104 to 112 compared with 87 to 92 for gasoline), and potentially more horsepower, it has a lower Btu rating than gasoline, which results in lower fuel economy.