Frequently Asked Questions

Just like petroleum diesel, biodiesel operates in combustion-ignition engines. Essentially no engine modifications are required, and biodiesel maintains the payload capacity and range of diesel. Pure biodiesel is not compatible with natural rubber, sometimes found in pre-1994 vehicles. Because it is a solvent, it can degrade natural rubber hoses and gaskets. This is not a problem with B20 blends (20 percent biodiesel/80 percent diesel) and below.

In fact, in its pure form or blends, biodiesel can be stored wherever petroleum diesel is stored, except in concrete-lined tanks. It handles like diesel and uses the same infrastructure for transport, storage, and use. At higher blend levels, biodiesel may deteriorate natural rubber or polyurethane foam materials.

The use of biodiesel and biodiesel blends results in a noticeable, less offensive change in exhaust odor, which can be a real benefit in confined spaces. In fact, equipment operators have compared it to the smell of French fries. Users also report having no eye irritation. Since biodiesel is oxygenated, diesel engines have more complete combustion with biodiesel than with petroleum.

The flash point (the point at which fuel ignites) for biodiesel in its pure form is a minimum of 260 degrees versus about 125 degrees Fahrenheit for regular No. 2 diesel. This makes biodiesel one of the safest fuels to use, handle and store.

Biodiesel is the first alternative fuel to have fully completed the Health Effects testing requirements of the Clean Air Act. The use of biodiesel in a conventional diesel engine results in a substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle and testing methods. The use of biodiesel decreases the solid carbon fraction of particulate matter (since the oxygen in biodiesel enables more complete combustion to CO2), and eliminates the sulfate fraction (as there is no sulfur in the fuel), while the soluble, or hydrocarbon, fraction stays the same or is increased. Biodiesel works well with new technologies such as catalysts, particulate traps, and exhaust gas recirculation. Soy biodiesel reduces carbon dioxide by 78% on a life cycle basis.

By using domestically produced, renewable fuels like biodiesel, the United States can reduce dependence on foreign countries for oil. Biodiesel has the highest energy balance of any fuel, further increasing its value in our energy portfolio. Every unit of fossil fuel it takes to make biodiesel results in 3.2 units of energy gain. Since petroleum diesel has a negative energy balance of .88, every gallon of biodiesel used has the potential to extend our petroleum reserves by four gallons.

Biodiesel is one of the most thoroughly tested alternative fuels on the market. A number of independent studies have been completed with the results showing biodiesel performs similarly to petroleum diesel while benefiting the environment and human health compared to diesel. That research includes studies performed by the U.S. Department of Energy, the U.S. Department of Agriculture, Stanadyne Automotive Corp. (the largest diesel fuel injection equipment manufacturer in the U.S.), Lovelace Respiratory Research Institute, and Southwest Research Institute. Biodiesel is the first and only alternative fuel to have completed the rigorous Health Effects testing requirements of the Clean Air Act. Biodiesel has been proven to perform similarly to diesel in more than 50 million successful road miles in virtually all types of diesel engines, countless off-road miles, and countless marine hours. Currently, more than 300 major fleets use the fuel.

One of the major advantages of biodiesel is the fact that it can be used in existing engines and fuel injection equipment with little impact on operating performance. Biodiesel has a higher cetane number than U.S. diesel fuel. In more than 50 million miles of in-field demonstrations, B20 showed similar fuel consumption, horsepower, torque, and haulage rates as conventional diesel fuel. Biodiesel also has superior lubricity and it has the highest BTU content of any alternative fuel (falling in the range between #1 and #2 diesel fuel).