Fact Sheet April 2008

Biodiesel is a domestically produced, renewable fuel that 

can be manufactured from new and used vegetable oils, 

animal fats, and recycled restaurant grease. Biodiesel’s 

physical properties are similar to those of petroleum 

diesel, but the fuel significantly reduces greenhouse gas 

emissions and toxic air pollutants. It is a biodegradable 

and cleaner-burning alternative to petroleum diesel.

Biodiesel can be blended and used in many different 

concentrations. They include B100 (pure biodiesel), B20 

(20% biodiesel, 80% petroleum diesel), B5 (5% biodiesel, 

95% petroleum diesel), and B2 (2% biodiesel, 98% petroleum diesel). The most common biodiesel blend is B20, 

which qualifies for fleet compliance under the Energy 

Policy Act (EPAct) of 1992.

Can I use B20 in my vehicle’s diesel engine?

As long as the vehicle was manufactured after 1993, 

biodiesel can be used in diesel engines and fuel injection 

equipment with little impact on operating performance. If 

your vehicle is older than that, beware. The engine could 

be assembled with incompatible elastomers, which can 

break down with repetitive high-blend biodiesel usage.

Regardless of your vehicle’s age, it’s a good idea to check 

original engine manufacturer (OEM) recommendations 

before using biodiesel. Most OEMs approve blends up to 

B5 in their vehicles. Some approve blends up to B20 if the 

fuel meets certain specifications and standards. One even 

approves B100 in certain types of farm equipment. 

If you can’t find OEM recommendations, check your 

engine manufacturer’s Web site or speak with a dealer 

to determine the biodiesel blend that’s right for your vehicle. In addition, you can find general information on the 

National Biodiesel Board (NBB) Web site (www.biodiesel.

org/resources/fuelfactsheets/standards_and_warranties.shtm). 

Manufacturer-specific information is also available.1

Is biodiesel readily available?

Biodiesel is available in all 50 states. NBB tallies show 

that 450 million gallons of biodiesel were sold in 2007, 

up substantially from 2 million gallons in 2000.2 As of 

January 2008, the United States had an annual production capacity of more than 2.2 billion gallons.3

Biodiesel Blends

The number of retailers, petroleum distributors, and 

biodiesel distributors offering biodiesel blends continues 

to grow. According to the Alternative Fuels Station Locator 

tool on the Alternative Fuels and Advanced Vehicles Data 

Center (AFDC) Web site, there are more than 800 biodiesel fueling sites across the country. To look up biodiesel 

stations in your area, visit http://afdcmap2.nrel.gov/locator.

Will biodiesel perform as well as diesel?

Testing results of engines operating on B20 show similar fuel consumption, horsepower, and torque to those 

operating on conventional diesel. Biodiesel has some 

additional desirable characteristics, including a higher 

cetane number (a measure of the ignition value of diesel 

fuel) and higher lubricity (the capacity for reducing friction) than U.S. diesel fuel. B20 also has an energy content 

between those of #1 and #2 diesel fuels.

Will biodiesel perform well in cold weather?

Just like common #2 diesel, certain high-freezing-point 

compounds in biodiesel will crystalize in very cold temperatures. Pure biodiesel crystalizes in warmer temperatures than #2 diesel fuel, but B20 blends are administered 

with the same fuel management techniques as #2 diesel. As temperatures get colder, proper blending for B20 

becomes more critical, and the fuel’s sensitivity to process 

variations increases. Blends of 5% biodiesel and below 

have a small impact on cold-flow properties (measures of 

low temperature operability). For more information on 

cold-flow properties and biodiesel handling, download 

Biodiesel Handling and Use Guidelines from www.nrel.gov/

vehiclesandfuels/npbf/pdfs/40555.pdf. 

Will biodiesel plug my vehicle filters?

Biodiesel has a solvent effect proportionate to the amount 

of biodiesel in the fuel. For example, B100 has a higher 

solvent effect than B20. This will clean your vehicle’s fuel 

system and could release deposits accumulated on tank 

walls and in pipes from previous diesel fuel usage. 

1 Source: www.biodiesel.org/pdf_files/OEM%20Statements/oem_matrix.pdf

2 Source: www.biodiesel.org/pdf_files/fuelfactsheets/Production_Graph_Slide.pdf 

3 Source: www.biodiesel.org/buyingbiodiesel/producers_marketers/

ProducersMap-Existing.pdf
Clean Cities

For more information about Clean Cities visit www.eere.energy.gov/cleancities

The release of deposits in higher biodiesel blends may initially clog filters, so you should be proactive in checking 

for and replacing clogged fuel filters. Once the build-up is 

eliminated, return to your regular replacement schedule. 

This issue is less prevalent with B20 and lower blends. 

There is no evidence that lower-blend levels plug filters. 

Will long-term biodiesel use affect my engine?

Studies of B20 and lower blends have not shown longterm effects for in-specification biodiesel. In general, B100 

can soften and degrade certain types of elastomers and 

natural rubber compounds over time. Using higher-level 

blends (above B20) can impact fuel system components 

(primarily fuel hoses and fuel pump seals) that contain 

elastomer compounds incompatible with biodiesel. The 

effect is lessened as the biodiesel blend level is decreased. 

For more information, visit www.biodiesel.org. 

Can I use vegetable oil in my diesel engine? 

Straight vegetable oil is not the same as biodiesel and is 

generally not considered an acceptable fuel for large-scale 

or long-term use. It is not a legal motor fuel, it doesn’t 

meet biodiesel fuel specifications and quality standards, 

and it is not registered with the U.S. Environmental 

Protection Agency (EPA). For more information, download 

“Straight Vegetable Oil as a Diesel Fuel,” a fact sheet available on the AFDC at www.eere.energy.gov/afdc/pdfs/39733.pdf. 

Is biodiesel cleaner burning than regular diesel? 

The use of biodiesel in conventional diesel engines substantially reduces emissions of unburned hydrocarbons 

(HC), carbon monoxide (CO), sulfates, polycyclic aromatic 

HCs, nitrated polycyclic aromatic HCs, and particulate 

matter (PM). The reductions of these compounds increase 

as the amount of biodiesel blended into diesel fuel increases. B100 provides the best emission reductions, but lowerlevel blends also provide benefits. B20 has been shown to 

reduce PM emissions by 10%, CO by 11%, and unburned 

HCs by 21% (see Figure 1). Studies of oxides of nitrogen 

emissions have provided contradictory results, and additional testing and analysis is ongoing.

Biodiesel use also reduces greenhouse gas emissions 

because the carbon dioxide released in biodiesel 

combustion is offset by the carbon dioxide sequestered 

while growing the feedstock. B100 use reduces carbon 

dioxide emissions by more than 75% compared to diesel. 

Using B20 reduces carbon dioxide emissions by 15%.

Does biodiesel need to meet any standards?

Biodiesel used in blends should meet specification D6751-

07B, a standard set by ASTM International to ensure the 

quality of U.S. biodiesel used in blends. Biodiesel meeting this standard is legally registered as a fuel blendstock 

or additive with the EPA. As of January 2008, ASTM 

International was developing specifications explicitly 

for biodiesel blends. 

Are incentives and credits available for biodiesel?

The American Jobs Creation Act of 2004 (Public Law 

108-357) created tax incentives for biodiesel fuels, 

which are available to blenders and retailers. Section 

1344 of EPAct 2005 extended the tax credit for biodiesel 

producers through 2008. The credits are $1 per gallon of 

agri-biodiesel and $.50 per gallon of waste-grease biodiesel. For more information, visit the State and Federal 

Incentives and Laws section of the AFDC at www.eere.

energy.gov/afdc/fuels/biodiesel_laws.html.

Where can I find more information on biodiesel?

Visit the Biodiesel section of the AFDC at www.eere.energy.

gov/afdc/fuels/biodiesel.html. 

0 20 40 60 80

NOx

CO

HC

100

Percent Biodiesel

-80%

-60%

-40%

-20%

0%

20%

Percent Change in Emissions

PM

Figure 1. Average Emission Impacts of Biodiesel for Heavy-Duty 

Highway Engines 

A Strong Energy Portfolio for a Strong America

Energy efficiency and clean, renewable energy will mean a stronger economy, a 

cleaner environment, and greater energy independence for America. Working 

with a wide array of state, community, industry, and university partners, the 

U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy 

invests in a diverse portfolio of energy technologies.

DOE/GO-102008-2542 • April 2008

Printed with a renewable-source ink on paper containing at least 

50% wastepaper, including 10% postconsumer waste.

Sponsored by the U.S. Department of Energy

Energy Efficiency and Renewable Energy 

Vehicle Technologies Program

For more information contact: EERE Information Center

1-877-EERE-INF (1-877-337-3463)

www.eere.energy.gov

Prepared by the National Renewable Energy Laboratory (NREL)

NREL is a U.S. Department of Energy National Laboratory

Operated by Midwest Research Institute • Battelle 

Source: EPA, Draft Report EPA 420-P-02-001, Ocotober 2002