Propane Vehicles

Propane is an excellent fuel of choice for farm vehicles (including tractors and heavy-duty trucks) because of its unique characteristics:

• Propane is safer (slower burning, higher ignition temperature) than gasoline.
• Propane is cleaner burning than diesel fuel or gasoline.
• Propane engines can produce as much power as diesel or gasoline engines, but with lower emissions.
• Propane leaves no residue, or fumes, and the fuel spills and other dangers associated with liquid fuels are not a concern with propane.
• Propane¹s clean-burning properties mean fewer oil and filter changes.
• Propane vehicles can be expected to have a longer engine life (often as long as 180,000 -200,000 miles).

Gasoline-powered cars and trucks can be converted to function as dual-fuel vehicles or to operate on propane alone. Gasoline tractor engines can also be converted to run on propane. In a properly- modified engine, tractors may actually exhibit an increase in horsepower because propane has a much higher octane rating than gasoline. Farmers often report that they can pull larger loads at faster speeds after a conversion to propane than they could prior to the conversion.

Engine Conversions

Existing engines can be converted to run on propane gas by modifying the carburetor and fuel intake valves and inlets. To operate on propane, a second "dry fuel" carburetor with a secondary fuel regulator, vacuum safety shutoff, and electric fuel shutoff is needed. Replacement carburetor kits are commercially available, but they must be matched with the model/year of the existing generator. Conversion costs will vary by type and size of engine.

Engine Research and Development

The Propane Education & Research Council (PERC) is actively funding engine research that will benefit the agricultural community. Two recent projects are described below:

• "Propane-Fueled Off-Road Engine and Tractor Development Project"
  • Conducted by the Southwest Research Institute
  • Project initiated in June 2001
  • Objective is to develop an economical, commercially viable propane-fueled heavy-duty engine as a practical alternative to diesel-powered off-road equipment.
  • A John Deere PowerTech 4.5L engine is being converted to run on propane fuel. The propane-fueled engine has demonstrated satisfactory performance, and tests have shown a substantial reduction in emissions compared to a baseline diesel engine.
• In August 2001, IMPCO's Engine Systems Division (a leading developer of advanced alternative fuel systems technology and components for internal combustion engines) received funding from the Council and the U.S. Department of Energy to develop a low-emission 2004 CARB/EPA certified engine package. The propane-fueled engine platform is scheduled for worldwide commercialization in November 2002. Primary targets for these low-emission certified industrial engines will be the agricultural irrigation and industrial equipment markets.