From Green Right Now Reports
GM announced today that its new lineup of heavy-duty diesel pickups will run on B20 biodiesel, which is a blend of 20-percent biodiesel and 80-percent conventional diesel that produces lower carbon dioxide emissions.
The announcement was made at the National Biodiesel Conference in Grapevine, Texas.
GM said its new Duramax 6.6L turbo diesel engine has been substantially revised to include B20 capability, as well as meet strict new emissions standards effective this year. The Duramax will power the redesigned 2011 Chevy Silverado and GMC Sierra heavy-duty pickups, as well as the Chevrolet Express and GMC Savana full-size vans. Chevrolet plans to unveil the 2011 Silverado heavy-duty trucks at the Chicago Auto Show on Feb. 10.
“B20 capability in our new heavy-duty trucks is the latest addition to a growing number of alternate fuel options offered by General Motors,” Mike Robinson, GM’s vice president of Environment, Energy and Safety Policy, said in a statement. “We are seeking different paths to fuel solutions in order to maximize efficiency, reduce emissions and minimize the dependence on petroleum.”
GM says it has with more than 4 million FlexFuel vehicles on the road today capable of running on E85 ethanol. Like ethanol, biodiesel is a domestically produced, renewable fuel made primarily of plant matter – mostly soybean oil.
Estimates by National Biodiesel Board indicate about 700 million gallons of the fuel were produced in 2008 – up from about 500,000 gallons in 1999. Market fluctuations caused production to decrease in 2009, but it is expected to rise with more mandates and the availability of approved vehicles, such as the 2011 Chevrolet Silverado and GMC Sierra heavy-duty trucks.
To make the Duramax 6.6L and its fuel system compatible with B20, GM said it upgraded some seals and gasket materials to withstand the ester content of biodiesel and included an upgraded fuel filter that includes a coalescing element. It improves the separation of water that may be present in the fuel, because biodiesel can attract and absorb water. Also, additional heating of the fuel circuit was added to reduce the chance of fuel gelling or waxing that could plug filters.
The Duramax 6.6L’s diesel particulate regeneration system features a downstream injector that supplies fuel for the regeneration process. This greatly reduces potential oil dilution, important with using biodiesel. Downstream injection saves fuel and works better with B20 than in-cylinder post injection.