Like its corporate sibling, the Chevrolet Silverado heavy-duty pickup, the GMC Sierra HD inherits an overhauled Duramax diesel engine option for 2017, which brings with it a nifty hood scoop. A 360-hp gasoline-fueled 6.0-liter V-8 remains standard and does not get the hood scoop.
The V-8 diesel engine really is the big news in heavy-duty Sierra land for 2017. That’s largely because of the 6.6-liter engine’s huge output numbers, from its 445 horsepower to its 910 lb-ft of torque. Those figures are up by 48 horsepower and 145 lb-ft over last year’s Duramax, putting it right in the hunt with Ford’s 6.7-liter Power Stroke diesel (440 horsepower, 925 lb-ft) and Ram’s Cummins 6.7-liter diesel (385 horsepower, 900 lb-ft). Improvements include the ability to run on B20 biodiesel as well as a damped steel oil pan and new rocker cover and fuel-system addenda that GMC claims will reduce noise.
Furthermore, the engine boasts a new and stronger block, higher-flow pathways for oil and coolant, electronic turbocharger control, and a new fuel system. That hood scoop even plays a role beyond vanity: It’s part of a new air-intake system that contributes to the diesel’s power production. A carryover Allison 1000 six-speed automatic transmission (albeit with a higher torque capacity and a new torque converter) bolts up behind the new Duramax. Having already experienced the diesel in the 2017 Silverado, we can attest to its relative quietness as well as its prodigious power.
There are few changes for the 2017 GMC Sierra heavy-duty trucks aside from the optional Duramax. Buyers can still choose between 2500 and 3500 grades, two- or four-wheel drive, and four trim levels: base, SLE, SLT, and Denali. A base, regular-cab 2500HD runs $35,085, while a 3500HD Denali 4×4 with the longer of the two available bed lengths starts at $59,830. The diesel engine adds $9005–$9255 to the cost of the Sierra 2500HD and 3500HD.