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 20% biodiesel and 80% conventional 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 (all OEMs accept the use of B5 and many accept the use of B20) of this alternative fuel don't void or affect it. 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 lowered 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%.
What is Clean Diesel?
Ultra-low sulfur diesel (ULSD) is diesel fuel with 15 parts per million or lower sulfur content. ULSD combined with advanced emission control technologies is referred to as clean diesel. This type of diesel is now the only diesel fuel used in all on-road diesel vehicles as of 2010. The sulfur content of ULSD has been reduced by 97% compared to diesel fuel used in the past. Biodiesel is also considered a USLD because it contains very low levels of sulfur.