Both the 2017 Chevy Silverado HD and 2017 GMC Sierra HD will be available with a new 6.6-liter Duramax turbodiesel V8 engine that has more power and added toughness.
As per the leaks, the new 6.6-liter turbodiesel V8 has 445 horsepower and 910 pound-feet of torque, which comes from as low as 1,600 rpm. These new figures seriously trump the 2016 HD Duramax’s ratings of 395 hp and 795 lb-ft. The GM models feature an engine that has been mostly reworked for improved strength and power: the engine block, heads, and crankshaft are all new, together with the boost control system. An added damped oil pan and updates to the rocker covers will lower idle noise by 38 percent, with the oil cooler getting a 50-percent boost in capacity. Visible from the outside, the hood scoop brings more air into the turbocharger as per the new air intake system.
The engine uses the same Allison six-speed automatic transmission, but with a replaced torque converter to deal with the increased torque. Chevy and GMC claim the new Duramax engine will start in -20°F temperatures in as little as three seconds, thanks to ceramic glow plugs and can also run on B20 biodiesel fuel.