2011 GMC Sierra All Terrain HD Concept

GMC today announces the new 2011 Sierra Denali HD, the first offering of the exclusive Denali line on a heavy-duty GMC pickup. The Sierra Denali HD leads a comprehensively redesigned lineup of 2011 Sierra 2500HD and 3500HD trucks that go on sale in early summer – including the most powerful diesel engine in the segment.Sierra HD’s new 6.6L Duramax turbo diesel delivers 397 horsepower (296 kW) at