Spy Shots—2017 Silverado 3500 HD Longbox With Updated Duramax Diesel Source SEMA This is the Chevy Silverado HD, featuring the latest Duramax diesel engine, caught cold weather testing in Michigan. GM is expected to give the Duramax diesel in the HD Silverado and Sierra trucks a revamp in order to keep power and efficiency competitive with the latest HD trucks from Ford and Ram, as well as the Nissan Titan XD. Reports suggest the current 6.6L V8 unit will be thoroughly worked over to dethrone the Ford Super Duty in efficiency and hauling capacities, pushing it comfortably over the 425 hp mark, and at least 860 lb.-ft. of torque. An eight-speed automatic transmission is also likely to become standard fare, but a 10-speed unit may not be far behind. 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 and carry newly downsized engines for better efficiency. Expect to see the Silverado and Sierra HD later this year.