"This is the Chevrolet Silverado HD featuring the latest Duramax diesel engine, caught cold-weather testing in Michigan.

"GM is expected to give the Duramax diesel in the Silverado and GMC Sierra HD trucks a revamp in order to keep torque and efficiency competitive with the latest Power Stroke and Cummins diesels from Ford and Ram.

"Reports suggest the current 6.6-liter V-8 unit will be thoroughly reworked to dethrone the current Ford Super Duty in efficiency and hauling capacities, pushing it comfortably over the 425-horsepower mark, with at least 860 pounds-feet of torque. A heavy-duty eight-speed automatic transmission is also likely to become standard fare, but a 10-speed unit may not be far behind. No word yet as to whether Allison will continue as GM's HD transmission supplier.

"We've heard reports that the face-lifted HD trucks are supposed to last until 2020 or so, when the next-generation GM pickups will adopt a more aluminum-intensive structure to reduce weight as well as carry newly downsized engines for better efficiency and payload capacity is anyone's guess."

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