Liquid Petroleum Gas, LPG

Also known as LP-Gas, LPG, GPL, autogas and even simply propane, LPG is a mixture of mostly propane and butane gas that has been compressed into a liquid. It is the most commonly used alternative fuel in the world.

truck delivers lpg

photo by Tim Lee

The Gas Processors Association requires LPG to be at least 90% propane in order for it to qualify as a transportation fuel. Currently, about 2% of the energy used in the United States is from propane and less than 2% of that propane is used for transportation fuel.


Pressurized liquid, clear, colorless, non-toxic


The chemicals that go into LPG, such as propane, are byproducts created during oil refining or through extracting heavy liquids during the processing of natural gas. They are separated from these products, then compressed into a liquid.

CO2 Emissions

LPG emits about half the carbon dioxide as conventional gasoline.


Currently, the infrastructure for propane is the largest among all alternative fuels. In the US alone there are about 2,500 fueling stations in operation.

Compared to Gasoline

The statistics vary, but according to the Global Autogas industry Network (GAIN) , LPG emits only half as much carbon monoxide, 40% as much hydrocarbons and 35% as much nitrogen oxides as gasoline.


It has enough energy density and allows for good driving range.

If spilled, LPG presents no threat to soil, surface water, or groundwater because it evaporates immediately on meeting the surrounding air.


A gallon of propane has about 25% less energy than a gallon of gasoline.

Although supply currently exceeds demand, the supply itself is limited, meaning global conversion to autogas is unlikely.

Converting a current vehicle to be able to run on LPG requires using the trunk space for the fuel tank. The weight of the tank also creates a subsequent drop in the car’s acceleration.

The Future…

The development of the Liquid Propane Injection (LPI) engine will lead to substantially higher fuel efficiency, thereby making it all the more attractive to the consumer.

Also, in 2007 Technology Review reported that researchers at MIT announced a chemical process for creating propane from sugarcane. The product, called biopropane, is a renewable fuel that could utilize propane’s existing infrastructure.

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