FAQ’s

What is Biodiesel?

Biodiesel is a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel is not petroleum based, but it can be blended at any level with petroleum diesel to create a biodiesel blend. You can use it in compression-ignition (diesel) engines with no major modifications. Biodiesel is simple to use, biodegradable, nontoxic and essentially free of sulfur and aromatics.

Is biodiesel used as a pure fuel or is it blended with petroleum diesel?

Biodiesel can be used as a pure fuel or blended with petroleum in any percentage ratio’s. B20 (a blend of 20 percent by volume biodiesel with 80 percent by volume petroleum diesel) has demonstrated significant environmental benefits with a minimum increase in cost for fleet operations and other consumers.

Can unaltered vegetable oil be used in a diesel engine?

This is not our recommendation, however, biodiesel is made from a base stock of vegetable oil and requires no alterations to your vehicle. It is possible to run a diesel vehicle on straight, unaltered, vegetable oil, but a few minor alterations are necessary. Conversion information is available in “From the Fryer to the Fuel Tank: The Complete Guide to Using Vegetable Oil as an Alternative Fuel” by Joshua Tickell (Tickell Energy Consulting, 2000).

Can I use biodiesel in my existing diesel engine?

Biodiesel can be operated in any diesel engine with little or no modification to the engine or the fuel system. Biodiesel has a solvent effect that may release deposits accumulated on tank walls and pipes from previous diesel fuel storage. The release of deposits may clog filters initially and precautions should be taken. Ensure that only fuel meeting the biodiesel specification is used.

(For a more complete list of frequently asked questions, please contact the National Biodiesel Board. Much of the above information reflects research and writing done by NBB staff.)

Do I have to modify my engine to use biodiesel?

Any vehicle that operates on diesel fuel can switch to biodiesel without engine modifications. Many municipal and school fleets are using biodiesel blends to improve air quality and reduce emissions. In fact, more than 1,000 major fleets in the U.S. run on biodiesel!

Does biodiesel perform as well as diesel?

Yes. Biodiesel can be used in existing engines and fuel injection equipment. It has a higher cetane number than diesel fuel. Biodiesel also has superior lubricity and has the highest BTU content of any alternative fuel (B11 is comparable to #2 diesel fuel).

Does using biodiesel put an engine warranty at risk?

No. Engine manufacturers warrant engines. Biodiesel is treated the same as any fuel you would use in your engine. See the Magnuson-Moss Warranty Act for more information.

Does biodiesel clog fuel filters?

Biodiesel acts as a solvent, removing petroleum buildup and cleaning fuel injectors, fuel lines, tanks and delivery systems over time. When first using biodiesel, you may need to change filters more frequently until the whole system has been cleaned of the deposits left by the petrodiesel. It is actually better for your engine.

Does biodiesel provide as much power as diesel?

Yes. Biodiesel offers enhanced power from higher cetane, plus improved lubricity for less engine wear and tear. 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. In more than 1.5 billion on-road miles and countless marine and off-road applications, biodiesel shows similar fuel consumption, horsepower, torque and haulage rates to conventional diesel fuel.

How do biodiesel emissions compare to petroleum diesel?

Biodiesel is the only 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 substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter compared to emissions from petroleum based diesel fuel. In addition, the exhaust emissions of sulfur oxides and sulfates (major components of acid rain) from biodiesel are essentially eliminated compared to diesel.

Does biodiesel have as much sulfur as petroleum diesel?

Soy-based biodiesel contains about 2 ppm of sulfur, and animal fat-based biodiesel can contain as high as 10 ppm of sulfur. Ultra Low Sulfur Diesel (ULSD) can contain up to 15 ppm of sulfur. Biodiesel is an excellent lubricant and can be blended with petroleum diesel to restore the lubricating properties petrodiesel loses when sulfur is removed.

Can biodiesel help mitigate “global warming”?

A 1998 biodiesel lifecycle study, jointly sponsored by the US Department of Energy and the US Department of Agriculture, concluded biodiesel reduces net CO2 emissions by 78 percent compared to petroleum diesel. This is due to biodiesel’s closed carbon cycle. The CO2 released into the atmosphere when biodiesel is burned is recycled by growing plants, which are later processed into fuel. It won’t solve the problem all by itself but it is certainly a step in the right direction.

Where can I buy biodiesel? Does it cost more than conventional diesel?

Biodiesel is available for sale at many local fuel stations. Google it or check with your local Chamber of Commerce. There are a number of bulk biodiesel dealers; contact the National Biodiesel Board for more information. It is also possible to manufacture your own homebrewed biodiesel by either purchasing a processor or building a DIY processor. Biodiesel can cost up to twice as much at the pump as petroleum diesel. As demand and commercial production of biodiesel increases, prices are expected to drop dramatically. As an alternative fuel, biodiesel is very competitively priced.

Where’s biodiesel made?

Biodiesel is a fuel made from any vegetable oil or animal fat that goes through a refinery process called transesterification. Commercially the most commonly used feedstock in the United States is soybean oil. Residentially you the most common is from WVO (Waste Vegetable Oil) Because biodiesel is made from American-grown feedstocks or WVO, every gallon of biodiesel purchased helps move the U.S. closer to energy independence.

How is biodiesel renewable?

Biodiesel is made from renewable feedstocks that are grown every year in the U.S. Unlike petroleum diesel made from earth’s steadily depleting fossil fuel resources, we can continue to raise more feedstocks for biodiesel. Our preferred method is to use WVO (Waste Vegetable Oil) from local restaurants (most owners will love you for taking this off their hands). This discarded oil is then recycled in a processor and put in your diesel powered heater, generator, vehicle, etc..

Does commercial biodiesel have an ASTM standard?

Biodiesel has a full ASTM standard. The American Society of Testing and Materials (ASTM)-the premier standard-setting organization in the United States-issued Specification D 6751 for all biodiesel fuel bought and sold in the U.S. A separate standard for B6-B20 blends has been passed by ASTM. It will be published later this year with its own ASTM number.