Biodiesel is a domestically produced, renewable fuel that can be manufactured from new and used vegetable oils, animal fats, or recycled restaurant greases. Biodiesel’s physical properties are similar to those of petroleum diesel, but it is a cleaner-burning renewable alternative. Research has shown that biodiesel also reduces emissions of toxic air pollutants in older on-road vehicles and in many off-road applications.
Biodiesel can be blended and used in many different concentrations, which include the following blends:
- B100 (pure biodiesel)
- B20 (20% biodiesel, 80% petroleum diesel)
- B5 (5% biodiesel, 95% petroleum diesel)
- B2 (2% biodiesel, 98% petroleum diesel)
B20 is one of the more common biodiesel blends available in the U.S. Pure biodiesel or biodiesel blended with petroleum diesel can be used to fuel diesel vehicles, providing energy security and emissions and safety benefits. However, higher blends should be avoided in older vehicles (manufactured before 1994) as their elastomers (rubber hoses and gaskets) could break down from repetitive use of blends above B20.
Nearly 80% of original equipment manufacturers (OEMs) of diesel vehicles approve blends up to B20 in some, or all, of their diesel vehicles. Some OEMs approve the use of B100 in certain models. You can find more information on the National Biodiesel Board website.
Biodiesel is safe and biodegradable, and its use significantly reduces greenhouse gas emissions and serious toxic air pollutants.
FAQsHow can I find biodiesel?
Biodiesel is available in all 50 states, so you can find a fueling station in any state. Please use the station locator on the bottom of the page to find a station near you. Additionally, the Alternative Fuels Data Center (AFDC) website has information on fueling sites across the country. Click here to use their station locator.
How well does biodiesel perform?
Engines operating on B20 exhibit similar fuel consumption, horsepower, and torque to engines running on conventional diesel. Biodiesel also has a higher cetane number (a measure of the ignition value of diesel fuel) and higher lubricity (the ability to lubricate fuel pumps and fuel injectors) than conventional diesel fuel, so it combusts easier and lubricates the fuel system better. B20’s energy content is between those of No. 1 and No. 2 diesel.
Does biodiesel burn cleaner than diesel?
The amount of the benefit will depend on the engine’s emission control technology, the age of the engine, the percent of biodiesel in the blend, and how the vehicle is operated. Older engines and technologies reap the greatest emissions benefits from the use of biodiesel. Biodiesel also reduces greenhouse gas emissions on a life-cycle basis. This is because the CO2 released during combustion is offset by the CO2 sequestered while growing the plants that are used to produce the fuel. For additional information, click here.
Will long-term biodiesel use affect my engine?
Studies of B20 and lower-level blends in approved engines have not demonstrated negative long-term effects. higher-level blends (above B20) may impact fuel system components in vehicles manufactured before 1994. The effects are lessened as the biodiesel blend level decreases. Click here for additional information.
How widely is biodiesel used?
Besides the fact that biodiesel is used in all 50 states, the U.S. Energy Information Administration has recorded the annual production of biodiesel in the U.S. totaled over 2.3 billion gallons per year. For more information on biodiesel usage and production, click here.
Are there standards for biodiesel?
BQ-9000 is the voluntary industry quality management program to ensure standards are being met. Biodiesel blends should start with B100 biodiesel that meets ASTM International Specification D6751. When blended for B5 and lower-level blends, the finished blend must meet ASTM D975, which requires these blends to meet the same fuel-quality specifications as conventional diesel fuel, so they have the same physical properties. For blends containing 6%-20% biodiesel, the finished blend needs to meet ASTM D7467. More complete standards can be found here.
Can I use straight vegetable oil in my diesel engine?
No. Straight vegetable oil is not biodiesel and is not a legal motor fuel. It doesn’t meet biodiesel fuel specification or quality standards. Simply put: be smart about what you put in your diesel engine. For more information, download the fact sheet, “Straight Vegetable Oil as a Diesel Fuel?” from the NREL website.
Where can I learn more?
For more information on biodiesel, including production, distribution, and fueling station locations, visit the biodiesel section of the AFDC website.