Spy Shots—Chevy Silverado and GMC Sierra HD Diesels Source: SEMA The shooters at KGP Photography caught a convoy of heavy-duty Chevrolet Silverado (top) and GMC Sierra (bottom) prototypes on the open roads, providing the best look yet at the rugged remakes of the crew-cab versions of the standard and dualie trucks due in 2016. The goal must certainly be to bump the current 6.6L Duramax turbo diesel's horsepower, torque and towing capacity to counter Ford's recently upgraded 6.7L Powerstroke V8 turbo diesel. Ford's revamped 6.7L diesel currently outguns GM's 6.6L units; the Ford generates 440 hp and 860 lb.-ft. of torque vs. GM's 397 hp and 760 lb.-ft. of torque. Deeper Breathing To Add Power Part of GM's strategy is to feed more air into the engine, via a new functional hood air intake designed into the trucks' redesigned hoods. The new air duct sits prominently near the leading edge of the hood—the GMC gets a circular mesh intake grille while the Chevy appears to get a diamond-shaped interweaving mesh grille insert. The Silverado and Sierra pickups had uncovered grilles and lightly camouflaged front bumpers, with a heavier vinyl hood hiding the hood's new air intake. The new breathing apparatus has been added in conjunction with a revamped diesel engine, reportedly using a modified turbo and new engine-management software resulting in a power boost to battle Ford's Powerstroke diesel engines. The prototypes were all sporting diesel exhaust, and a fuel fill-up had confirmed that these trucks were thirsting for diesel fuel. The fuel door reads "Ultra Low Sulfur Diesel Fuel Only."