Diesel Vehicles Using Biodiesel
Biodiesel and conventional diesel vehicles are one in the same. Although light-, medium-, and heavy-duty diesel vehicles are not technically "alternative fuel" vehicles, many are capable of running on biodiesel. Biodiesel, which is most often used as a blend with regular diesel fuel, can be used in many diesel vehicles without any engine modification. The most common biodiesel blend is B20, which is 6% to 20% biodiesel blended with petroleum diesel. B5 (5% biodiesel, 95% diesel) is also commonly used in fleets.
Before using biodiesel, be sure to check your engine warranty to ensure that higher-level blends of this alternative fuel don't void or affect it (all OEMs accept the use of B5, and many accept the use of B20). High-level biodiesel blends (blends over B20) can have a solvency effect in engines and fuel systems that previously used petroleum diesel which may result in degraded seals and clogged fuel filters.
Biodiesel improves fuel lubricity and raises the cetane number of the fuel. Diesel engines depend on the lubricity of the fuel to keep moving parts from wearing prematurely. Federal regulations have gradually reduced allowable fuel sulfur to only 15 parts per million, which has often resulted in lower aromatics content in diesel fuel. One advantage of biodiesel is that it can impart adequate lubricity to diesel fuels at blend levels as low as 1%.