2011 GMC Sierra Denali Duramax

GMC debuted their new 2011 Sierra Denali HD, the first offering of the exclusive Denali line on a heavy-duty GMC pickup. While GM claims an all-new redesigned truck, much of what is new is most obviously under the hood.

To that the new Sierra HD’s optional clean sheet design 6.6L Duramax turbo diesel delivers 397 horsepower (296 kW) at 3,000 rpm and 765 lb.-ft. of torque (1,037 Nm) at 1,600 rpm. A Vortec 6.0L gas V-8/six-speed automatic power train is standard and the new Duramax 6.6L turbo diesel/Allison 1000 six-speed transmission power train is available.

The new 6.6L Duramax diesel delivers segment-best power, up to 11-percent greater highway fuel economy, up to 63-percent lower emissions, B20 biodiesel capability and quicker acceleration. A larger fuel tank and fuel economy improvements allow up to 680 miles between fill-ups with the 6.6L Duramax turbo diesel. And an all-new “smart” exhaust brake feature provides greater control on grades and reduced brake pad wear.

Compared with Ford Super Duty’s urea-based system, GMC says Sierra HD’s selective catalytic reduction after-treatment system delivers better overall diesel performance, with a range of about 5,000 miles between DEF refills. Its optimized combustion and after-treatment process provides about 700 miles between diesel particulate filter regenerations. A new Allison 1000 six-speed automatic transmission works with the Duramax 6.6L to deliver greater fuel economy, quicker acceleration, greater towing capability and exhaust brake system.

The iconic Denali four-bar, chrome grille with round air inlets distinguishes the Sierra Denali HD on the outside, along with body-color bumpers, chrome door handles, chrome accents and 18- and 20-inch polished forged aluminum wheels.


The new Sierra Denali HD is offered exclusively in the Crew Cab standard box configuration on the 2500HD chassis, providing a spacious cabin with room for up to five. As with other Denali models, including the new Acadia Denali, the cabin is unique with standard premium touches. It includes Denali-specific brushed aluminum trim, power-adjustable pedals, a Bose premium surround audio system and 12-way power seats. Along with an optional heated steering wheel, heated and cooled leather-appointed seating is available. The exterior is offered in three colors: Black, Stealth Gray and White.

The rest of what is all-new is the chassis. Engineers developed 11 all-new, fully boxed frame assemblies to improve durability and ride characteristics and support increased capabilities. The frames have increased cross sections and use more high-strength steel for greater durability, higher towing capacity and improved ride and handling; the front sections are hydro formed. The bending and beaming stiffness of the frames is increased 92 percent and 20 percent, respectively, with the fully boxed sections enhancing torsional stiffness by a factor of five.

A completely redesigned independent front suspension system offers up to a 25-percent greater front axle weight rating – up to 6,000 pounds (2,721 kg) front gross axle weight rating (FGAWR) – so a snow plow can be used on all 4WD cab configurations with the available snow plow prep package. Sierra’s signature short-long arm/torsion bar front suspension design is retained, but now features new, forged steel upper control arms that are stronger and lighter than their predecessors.

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DieselDig Staff

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