General Motors has yet to officially unveil its next-generation Duramax diesel, but the automaker revealed today that the new engine -- which will power the 2011 Chevrolet Silverado HD and GMC Sierra HD models -- is capable of running on a 20-percent blend of biodiesel (B20).
"B20 capability in our new heavy-duty trucks is the latest addition to a growing number of alternate fuel options offered by General Motors," said Mike Robinson, GM's vice president of Environment, Energy and Safety Policy.
Biodiesel is a byproduct of mixing alcohol, animal fats or vegetable oils, and a catalyst. The substance itself contains no petroleum, although it is often blended with traditional diesel fuel. Twenty percent of B20, for instance, is biodiesel, with the remaining 80 percent comprised of diesel oil. According to the National Biodiesel Board, a B20 blend can reduce hydrocarbon emissions by 20 percent, and cut carbon monoxide and particulate matter by 12 percent.
Although B20 is the highest blend the new Duramax can accept, it's a substantial improvement over the current engine, which can run nothing higher than B5. To ready the engine for the fuel, GM needed to upgrade seals, fuel lines, and gaskets to endure the corrosive properties of the fuel. Additionally, fuel filters were improved, and the entire fuel circuit is heated to help prevent gelling in cold weather.
Ford's new 6.7-liter Power Stroke turbo-diesel V-8, found in the new 2011 Super Duty, is also designed to be B20 compliant. Dodge offers its heavy-duty Ram with a B20-compliant version of the Cummins 6.7-liter turbo-diesel I-6, but only to commercial and fleet customers.
Look for more specifications on the new Duramax and the 2011 Silverado HD to emerge later this week, when GM's largest full-size trucks are unveiled at the 2010 Chicago auto show.