Interesting but subjective perspectiveshttp://www.energy.ca.gov/afvs/lpg/Liquefied Petroleum Gas / Propane-Powered VehiclesOverviewMore than 350,000 vehicles, mostly in fleets, are traveling the nation's highways under propane power. Also known as LPG (or liquefied petroleum gas, a category that also includes butane and ethane), propane is powering taxis in Las Vegas; school buses in Kansas City and Portland, Oregon; sheriff and police cars in other communities; and in dozens of fleets around California. Propane is used in both light- and medium-duty vehicles. Estimates have placed the number of registered vehicles in California that are powered by propane as high as 40,000. Propane has been used as a transportation fuel for more than 60 years around the world.Propane is a gas in its natural state. It turns to liquid under moderate pressure and is stored in vehicle fuel tanks at about 200 pounds per square inch or pressure. When liquid propane is drawn from the tank, it changes back to a gas before it is burned in the engine. Propane is a by-product of petroleum refining and from natural gas production. In California, propane is mostly produced from the petroleum refining process, though across the country, propane is mostly a by-product of natural gas production. The federal government lists propane as an alternative fuel. Propane is a clean fuel which offers a range closest to gasoline. One gallon of propane contains less energy than a gallon of gasoline (82,485 British thermal uunits (Btu) for propane versus 115,400 Btu for gasoline), but propane companies say the miles per gallon should be about equal if the vehicle is tuned properly. LPG engine efficiency and fuel economy remain a subject of study and debate. Industry claims of equal miles per gallon using LPG compared to gasoline do not appear readily verifiable. Compared to gasoline, propane vehicles emit about one-third less reactive organic gases, reduce nitrogen oxides by about 20 percent, and show a reduction of about 60 percent in carbon monoxide. Propane is widely available in urban areas or refueling facilities can be installed on-site for fleet use. It can also be found in rural areas, where propane is used for heating and cooking and where natural gas is not available, and at service stations that refuel recreational vehicles' propane tanks. In California, there are thousands of locations (mostly at service stations) to fuel with propane. Converting an automobile or light-duty truck from gasoline to propane costs about $1,000 - $2,000 and can usually be done in one day. Conversions must comply with safety standards set by the National Fire Protection Association, and kits must be certified by the California Air Resources Board. (Contact ARB for its latest list of certified equipment and installers.) Modifications typically include: a heavy steel or high- strength fuel tank added to the trunk or truck bed, fuel lock filter/shut- off valve, vaporizer/regulator, and air/fuel mixer. Conversion kit parts are reusable. Dual-fuel gasoline/propane systems are also currently available. A drawback commonly cited about propane vehicles is the loss of trunk space in dual-fuel passenger vehicles due to installation of the tank, which is about the size of a spare tire or larger. On the positive side, propane-powered vehicles reportedly have less carbon build-up compared to gasoline- and diesel-powered vehicles. According to the National Propane Gas Association, spark plugs from a propane vehicle last from 80,000 to 100,000 miles and propane engines can last two to three times longer than gasoline or diesel engines. Propane retail prices were, on average, about the same as unleaded gasoline prices during the late 1980s and 1990s. The Energy Commission forecasts future propane prices as less expensive than gasoline. Propane prices, however, can fluctuate widely and are often tied to oil prices. Shortages of propane, such as the shortage in New England during a cold wave a number of years ago, can also increase propane prices quickly. The Energy Commission was involved in a side-by-side comparison of 113 fleet delivery vehicles in Southern California. Propane was one of the five fuels studied in the $11 million CleanFleet program. Federal Express is the fleet operator, and Battelle Memorial Institute is the technical contractor. The two-year test program concluded in October 1994, and propane was considered a good fuel for use in delivery vehicles.
Current Vehicles Offered For SaleSome auto manufacturers are offering a propane option (in passenger cars, vans, light pickup trucks, and heavier-duty engines) in their model line-up or offering engines that have been optimized for gaseous fuels. It would then be up to the purchaser to have the vehicle converted to propane with third-party equipment. Ford is selling its F-700 series medium-duty truck with a California Air Resources Board-certified propane engine option. The vehicle rquires only permanent installation of the LPG tank. Chevrolet offers its 5.7 liter V-8 pickup truck/van engine with a "propane prep engine" option.For more information about propane in California, contact:
(916) 962-2280 Propane Vehicle Council |