Benefits & Considerations
Also known as liquefied petroleum gas (LPG), propane is a domestically produced, well-established fuel. Using propane as a vehicle fuel increases energy security, provides convenience and performance benefits, and improves public health and the environment.
In 2014, the United States imported about 27% of the petroleum it consumed and transportation accounted for more than 69% of total U.S. petroleum consumption. With much of the worldwide petroleum reserves located in politically volatile countries, the United States is vulnerable to supply disruptions.
Fueling vehicles with propane is one way to diversify U.S. transportation fuels. The vast majority of propane consumed in the United States is produced here and distributed via an established infrastructure. Using propane vehicles instead of conventional vehicles increases U.S. energy security.
Vehicle and Infrastructure Availability
A variety of light-, medium-, and heavy-duty propane vehicle models are available through original equipment manufacturers (OEMs) and select dealerships. For options, see the Alternative Fuel and Advanced Vehicle Search, the Clean Cities Vehicle Buyer's Guide (pdf) or the Clean Cities Guide to Alternative Fuel and Advanced Medium- and Heavy-Duty Vehicles (pdf).
While propane vehicles can cost several thousand dollars more than comparable gasoline vehicles, the cost of propane is typically lower than gasoline, so the return on investment can be quick. Fleets and consumers also have the option of economically, safely, and reliably converting in-use light-, medium-, and heavy-duty gasoline vehicles for propane operation using qualified system retrofitters. It's critical that all vehicle and engine conversions meet the emissions and safety regulations and standards instituted by the U.S. Environmental Protection Agency, the National Highway Traffic Safety Administration, and state agencies like the California Air Resources Board. Learn about propane vehicle conversions.
By using the AFDC Station Locator tool, fleets and private users can identify public and private stations near them. Propane stations are categorized as either primary or secondary, and the methodologies section explains the categories, based upon their experience fueling vehicles. Fleets can use existing public infrastructure or work with local propane marketers to establish private infrastructure. It is important that fleets understand how to negotiate a supply contract. Costs will depend on the volume of fuel that’s indicated in the contract and the complexity of the equipment being installed. Learn more about the cost of propane infrastructure (pdf).
Fuel Economy and Performance
Propane at primary infrastructure sites costs less per gallon than gasoline and offers a comparable driving range to conventional fuel. Propane has a higher octane rating than gasoline (104 to 112 compared with 87 to 92 for gasoline) and potentially more horsepower, but its lower British thermal unit (Btu) rating per gallon results in lower fuel economy. However, the price per gallon can quickly offset the lower fuel economy.
The potential for lower maintenance costs are one reason behind propane's popularity for high-mileage vehicles. Propane's high octane rating, combined with its low-carbon and low oil-contamination characteristics, has resulted in improved engine life compared to conventional gasoline engines. Because the fuel's mixture of propane and air is completely gaseous, cold start problems often associated with liquid fuels can be reduced.
Public Health and Environment
Compared with vehicles fueled by conventional diesel and gasoline, propane vehicles can produce lower amounts of some harmful air pollutants and greenhouse gases, depending on vehicle type, drive cycle, and engine calibration. Learn more about propane emissions.