Biodiesel FAQs

What is biodiesel?

Soy-based biodiesel is soy methyl esters. It is made from soybean oil, by removing the glycerine from the oil in a process known as transesterification. Glycerine is found in hundreds of consumer products. Biodiesel can be made from many different kinds of oil, including recycled french fry oil.

How do you use it?

Biodiesel can be used as is, or can be mixed with petroleum diesel. Many people and fleets opt to use B20, a mixture of 80 percent petroleum diesel and 20 percent biodiesel. This is the optimum cost-benefit blend level. Biodiesel readily mixes and stays mixed with petroleum diesel at ambient temperatures.

What are the benefits of biodiesel?

The first thing you'll notice is a cleaner smelling exhaust - some users have compared it to the smell of French fries. Biodiesel also will reduce emissions, provide a cleaner burning exhaust, improve lubrication, improve cetane levels, and help clean injectors, fuel lines, pumps and tanks. It is also safer to store and transport since it has a higher flash point than traditional diesel and is classified only as combustible, not flammable or explosive. Consider keeping a handy five-gallon container on board your boat as emergency fuel.

And, because it is a domestically produced and renewable fuel, biodiesel is a compliance method under the federal Energy Policy Act. In fact, it's the least-cost, easiest to use compliance method for fleets subject to those requirements.

How does biodiesel generate EPACT credits?

Every 450 gallons of biodiesel consumed in vehicles over 8,500 lbs. equals one vehicle credit. Fleets must burn 2,250 gallons of B20 to meet the credit. Some restrictions apply. Ask your biodiesel fuel provider for more information.

How much does it cost? Where can I buy it?

The cost of biodiesel depends on how much you buy (for example, 5 gallons vs. 5,000), whether you buy it pure or pre-blended with petroleum, and how much you'll need to pay in shipping. Contact a manufacturer through the National Biodiesel Board to find an exact price.

Is biodiesel safe for the environment?

Biodiesel is safe for both the air and water. In its pure form it is non-toxic and biodegradable, which is especially important in sensitive or protected waterway areas. It is also free of sulfur and aromatics, which reduces harmful emissions. When added to petroleum diesel, it makes fuel burn cleaner. However, any fuel spill still needs to be reported and cleaned up in accordance with regulations.

Will biodiesel harm my boat in any way?

You should know that at higher blend levels, biodiesel's solvent properties, over time, may begin to react with certain types of rubber gaskets and hoses. You should also be aware that biodiesel will clean fuel tanks and line of built-up residues which will then accumulate in the fuel filter. So you may have to change your filters more frequently when first using biodiesel. Also, because of its solvent properties, you should promptly wipe up any spills that should occur on your boat with soap and water so that your gelcoat and teak are not affected.

Biodiesel Use Checklist

• Check fuel filters frequently during early use of biodiesel. The fuel's cleaning abilities may loosen debris that could clog your filter.
• Use the same procedures against fungal growth and winter freezing with biodiesel as you would with petroleum diesel.
• Biodiesel splash blends in the tank readily with petroleum diesel.
• Add biodiesel first and top off the tank with your regular petroleum diesel.
• Store biodiesel-soaked rags in a safety can to avoid the risk of fire due to spontaneous combustion.
• Wipe up spills immediately to avoid damage to teak, gelcoats or paint due to biodiesel's solvent properties.
• Attempt to use biodiesel within one year of purchase. All fuels, including petroleum diesel, have a shelf life.

Go back to general Biodiesel info.