Biodiesel Basics

For more detailed information on particular biodiesel topics, click on the relevant pages below.

B20                  Marine Applications                              Maintenance and Storage         Air Quality & Health Benefits

B99                  Home Heating                                    Engine Performance                 Warranties

For downloadable PDFs on basic biodiesel topics, click on the links below.

Download Biodiesel for Business:  Biodiesel Basics PDF      Download Biodiesel for Business:  B20 PDF

Download Biodiesel for Business:  B99 PDF                     Download Biodiesel Basics (personal use) PDF

Download Biodiesel for Vehicles (personal use) PDF         Download Biodiesel Handling and Use Guidelines Manual PDF

What is biodiesel?

Biodiesel is a cleaner burning, renewable fuel for diesel engines made from oilseed crops (like canola or soybean) or from used cooking oil and other fats. The production process uses an alcohol and catalyst to remove glycerol from oil to produce a fuel which is chemically defined as a mono-alkyl ester. Biodiesel can be used in existing diesel engines with little or no mechanical modification.

Biodiesel has many benefits. It is simple to use, biodegradable and nontoxic. Biodiesel can be blended at any level with standard petroleum diesel to create a biodiesel blend. Typical blends used are B5 (a blend of 5% biodiesel and 95% petroleum diesel), B20, and B99. When blended at less than 6%, biodiesel is considered an approved additive. Biodiesel is registered with the U.S. Environmental Protection Agency for use as a fuel and as a fuel additive.

Commercially produced biodiesel must meet a demanding fuel testing regimen, ASTM D6751, which guarantees the fuel will perform properly in all diesel engines.

B20 has been widely used with excellent results. The National Renewable Energy Laboratory and numerous state and federal fleets, including all branches of the U.S. military, have performed more than 50 million miles of road testing on B20, the results of which have only been positive.

Does it matter what biodiesel blend I use?

No, you can blend it in any percentage with petroleum diesel, and can change the blend in the fuel tank at any time, depending on availability (and cold weather concerns).

What other advantages does biodiesel have?

Besides the environmental and local economic advantages, biodiesel has a higher cetane number than petro diesel, a safer flash point and also provides lubrication. This ‘lubricity’ is especially important when blended with the new ultra-low sulfur diesel, because the new engines run better with this additional lubrication.

Can biodiesel be used for home heating?

Yes. Biodiesel in any blend burns very efficiently in oil furnaces and boilers. Some heating maintenance technicians have specialized in preparing furnaces for biodiesel. Most home heating fuel supply firms offer biodiesel, and report positive experiences from their customers.

If I start using biodiesel, can I go back to petroleum diesel?

Yes! Successful businesses depend upon versatility. With biodiesel, you can easily switch back and forth between regular biodiesel and petroleum diesel, and between various biodiesel blends.

Does biodiesel perform as well as diesel?

A major benefit of biodiesel is that it can be used in diesel engines and fuel injection equipment with little impact on operating performance. In more than 50 million miles of in-field experience, B20 showed similar fuel consumption, horsepower, torque, and haulage rates compared with conventional diesel. Biodiesel has a higher cetane number than diesel, resulting in a more complete combustion of the fuel. This improves engine efficiency, can improve the power output of the engine, and results in less white smoke.

What about fuel quality?

Commercially sold biodiesel must meet quality standards created specifically for biodiesel known as ASTM (American Society for Testing and Materials) D 6751. These technical standards ensure consistent, high quality fuel that will perform properly in all diesel engines.  Click here for more information on biofuel testing and quality assurance in the Northwest.

Are there maintenance issues with biodiesel?

Biodiesel users appreciate that this fuel can be used in any diesel engine with little or no modification to the engine or fuel system. With higher blends of biodiesel, fuel filters may need to be changed after the initial biodiesel switch and precautions may need to be taken in cold weather. Go to Maintenance Procedures for complete details.

How does biodiesel impact my engine warranty?

Engine manufacturers’ warranties only cover the manufacturers’ parts and workmanship. These warranties do not cover fuel whether it’s regular diesel, ultra low sulfur diesel, or biodiesel. The use of biodiesel in diesel engines does not void these warranties. If there are engine problems caused by a fuel (whether that fuel is petroleum diesel or biodiesel) these problems are the responsibility of the fuel supplier. Whether or not a biodiesel blend is “recommended” is separate from the question of whether the use of biodiesel affects engine warranty coverage. Typically an engine company will define what fuel the engine was designed for and will recommend which fuel to use. All major engine companies have approved B5 as a recommended fuel, and most are moving to approve blends up to B20.  Click here for more information on biodiesel and warranties.