The Sierra Denali HD leads a comprehensively redesigned lineup of 2011 Sierra 2500HD and 3500HD pickup trucks.

Sierra HD's new 6.6L Duramax turbo diesel delivers 397 horsepower at 3,000 rpm and 765 lb.-ft. of torque at 1,600 rpm.

The 2011 Sierra Denali HD comes exclusively on the 2500HD chassis, in a 4WD crew cab standard box configuration. A Vortec 6.0L gas V-8/six-speed automatic powertrain is standard and the new Duramax 6.6L turbo diesel/Allison 1000 six-speed transmission powertrain is available.

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 2011 Sierra HD has increased towing capability (20,000 lbs.) and payload (6,335 lbs.) supported by all-new fully-boxed, high-strength-steel frames and strong suspensions for maximum capability and exceptional ride characteristics.

A completely redesigned independent front suspension system offers up to a 25-percent greater front axle weight rating -- up to 6,000 pounds Front Gross Axle Weight Rating, so a snow plow can be used on all 4WD cab configurations with the available snow plow prep package.

The 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 Allison 1000 also features driver shift control with tap up/tap down shifting and a patented elevated idle mode cab warm-up feature. Also, the tow/haul mode reduces shift cycling for better control and improved cooling when towing or hauling heavy loads.