Biodiesel can be blended and used in many different concentrations. The most common are:
B100 (pure biodiesel)
B100 and other high-level biodiesel blends are less common than B20 and lower blends due to a lack of regulatory incentives and pricing. B100 can be used in some engines built since 1994 with biodiesel-compatible material for certain parts, such as hoses and gaskets. B100 has a solvent effect, and it can clean a vehicle’s fuel system and release deposits accumulated from petroleum diesel use. The release of these deposits may initially clog filters and require frequent filter replacement in the first few tanks of high-level blends.
B20 (20% biodiesel, 80% petroleum diesel)
B20 is the most common biodiesel blend in the United States. B20 is popular because it represents a good balance of cost, emissions, cold-weather performance, materials compatibility, and ability to act as a solvent. Most biodiesel users purchase B20 or lower blends from their normal fuel distributors or from biodiesel marketers. Regulated fleets that use biodiesel blends of 20% (B20) or higher qualify for biodiesel fuel use credits under the Energy Policy Act of 1992.
B5 (5% biodiesel, 95% petroleum diesel)
Low-level biodiesel blends, such as B5 are ASTM approved for safe operation in any compression-ignition engine designed to be operated on petroleum diesel. This can include light-duty and heavy-duty diesel cars and trucks, tractors, boats, and electrical generators.
B2 (2% biodiesel, 98% petroleum diesel)
Blends like B2 and B5 are popular fuels in the trucking industry because biodiesel has excellent lubricating properties, so usage of the blends can benefit engine performance.