The Sierra 3500HD is the biggest, most capable, and priciest pickup truck that GMC sells. For 2017, it receives more power and more strength thanks to the arrival of an all-new diesel engine helping it to tow and haul tens of thousands of pounds with ease.
While the new diesel engine retains its Duramax branding and 6.6-litre displacement, the V8 oil-burner is a significantly different. The engine block and head design are different, and it features a new fuel-delivery system to improve efficiency and refinement. The engine breathes through a functional hood scoop, which channels up to 60 percent more air into the engine. It’ll also run on B20 biodiesel – something the old Duramax couldn’t do.
The new engine elevates GMC’s status in the pickup truck ranks to near class-leading outputs. Its 445 horsepower (+12%) and 910 lb-ft of torque (+19%) put up a good show but ultimately fall short of the 925 lb-ft the new Ford Super Duty diesel produces. Strength like this requires a transmission that’s equally as strong – only an updated Allison 1000 six-speed automatic will do.
The standard engine on all 3500HDs is a 6.0-litre V8 engine that makes 360 hp and 380 lb-ft of torque, and can run on E85; it comes mated to a six-speed automatic. This engine is also available with a conversion kit that allows it to run on CNG, though power outputs are reduced.
In addition to the new diesel powerplant, the Sierra 3500HD also gets new exterior colours (Dark Slate Metallic, Pepperdust Metallic), and available six-spoke polished 20-inch wheels. Models featuring the gas-powered engine also get a capless fuel filler; diesel models have a regular cap. The Denali trim level gains wireless device charging and a remote-locking tailgate. All Sierra HDs get the Teen Driver technology system, which is also featured on the Acadia and Yukon, as standard equipment.
Available cab and bed configurations include a regular cab with long box (eight feet), double cab with standard (6.5 feet) or long box, and crew cab with standard or long box. 2WD and 4WD are available, depending on trim, and buyers can configure the 3500 with a single or dual rear wheels.
The most capable versions of the 3500HD with the Duramax diesel engine can tow up to 10,569 kg (23,300 lbs), and have a max payload rating of 3,245 kg (7,153 lbs). Helping to making towing more managable, GMC has made a factory-installed fifth-wheel hitch, trailer brake controller, and fully-integrated exterior cameras for towing assistance available. Last year’s update to the Sierra also saw it gain a digital steering assistant, which greatly improves low-speed maneuverability and stability at higher speeds.
GMC offers the Sierra 3500HD in base, SLE, SLT, and Denali trims, GMC’s luxe trim grade. All models have comfortable cabins with intuitive dashboard layouts, with premium trims benefitting from leather seats, soft-touch dash and door trim, and plenty of connectivity options. Most trims feature a 7.0-inch touchscreen infotainment system with USB ports, Bluetooth, OnStar with 4G LTE in-truck internet, and Apple CarPlay and Android Auto. A larger 8.0-inch option includes navigation, a smaller 4.3-inch display audio system is standard on the base Sierra.
In terms of active safety features, the 3500 HD is available with lane departure warning, front and rear park assist, and a safety alert seat, which get bundled together in the Driver Alert Package. A reverse camera is standard on all trims, except the base where it is included as a part of the Convenience Plus Package. The Sierra is not yet available with radar cruise control or emergency autonomous braking, but it can be equipped with forward collision warning.