The U.S. Environmental Protection Agency published the final rule on "Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements" on January 18, 2001. The rule stated that new vehicles for sale by model year 2007 will need to cut harmful pollution by 95 percent. In order to allow for modern pollution-control technology to be effective on trucks, buses, etc, the sulfur content of diesel fuel must be lowered. The Agency is requiring a 97 percent reduction in the sulfur content of highway diesel fuel from its current level of 500 parts per million to 15 parts per million.
The standards were based on the effect sulfur has on catalytic exhaust emission control devices or other effective emissions control devices. Unfortunately, the dramatic reduction in the sulfur content of diesel will reduce the fuel’s natural lubricity. This would translate into excessive engine wear and higher maintenance costs.
It’s a good thing biodiesel has demonstrated that it contains virtually no sulfur! Pure raw soy biodiesel, or B100, already meets the new sulfur requirements mandated by the U.S. EPA. Blending biodiesel with petrol diesel at just a 1 or 2 percent level increases lubricity up to 65%! As a blending stock, biodiesel can play a large role in helping refiners meet future sulfur specification for particular batches of ultra-low sulfur diesel they may produce.
In addition to excellent lubricating properties, biodiesel is a super solvent and has superior burn characteristics. The solvency keeps the engine clean while high oxygen and cetane ratings make biodiesel a premium fuel. Numerous testimonials exist that state maintenance costs have been reduced as a result of biodiesel keeping engines clean and happy.