A true exercise in realistic possibility thinking, the GMC Sierra All Terrain HD Concept made its formal debut at the 2011 North American International Auto Show. Although this one-off was created to endow the newly-minted version of GMC's Heavy Duty full-size pickup with a unique sense of style and enhanced go-anywhere functionality, Carl Zipfel, design manager admits: "We're excited about the design elements and exploring how they could apply to future GMCs."
Finished in Iridium Metallic, the GMC Sierra All Terrain HD Concept boasts a comprehensive bodywork makeover. Up front, the new clip features a bolder take on the standard Sierra HD look with a larger, free-flow grille and a cleaner fascia treatment that features an integrated bumper, frame-mounted tow hooks, LED headlamps/fog lamps/parking lamps/turn signals, a forced-air induction hood and revamped fenders with more aggressive flares.
Out back, the Sierra All Terrain HD Concept swaps its standard bed for a shorter five-foot eight-inch alternative from a Sierra Crew Cab. In addition to being set off with a similar streamlined bumper treatment, LED taillamps and major fender flares to house custom 35-inch-tall BFGoodrich KM2 "mud terrain" tires mounted on 20-inch machined aluminum wheels, the HD Concept's bed also features a composite liner, lockable, illuminated storage compartments, LED floodlights, a 110V power outlet and an on-board air compressor. As a final touch, motorized deployable assist steps facilitate access/egress to both the passenger compartment and the bed area.
Although it retains the standard four-wheel-drive system, 397-horsepower 6.6-liter Duramax turbodiesel V8 and six-speed automatic transmission, to keep this GMC Concept truck All-Terrain honest, the engineering team did an equally comprehensive rework of its suspension. In addition to substantially widening its track dimensions, the All Terrain Concept boasts nearly three more inches of ground clearance -- 21.1- inches at the rockers, 11.8-inches at the skid plates -- improved approach/departure angles, a full composite underbody pan, custom front control arms, unique Fox off-road shock absorbers with remote oil reservoirs, front/rear jounce shocks, and an electronically disconnectable front stabilizer bar.
Inside, the GMC Sierra All Terrain HD Concept steps up its Denali-level trim with a host of tough-and-techy touches. The seats are covered in two-tone gray leather with an embossed carbon-fiber cloth look set off by red contrast stitching while rest of the interior trappings match rich leather with stainless-steel mesh and satin chrome accents. Also of note is its new production-intent navigation radio system that will be used in future GMC vehicles. This premium package uses an 80GB hard drive in place of the normal disc mapping and also brings DVR-style "time lapse playback" that can accommodate up to 20 minutes of recording/playback from the AM/FM/XM radio.
While the GMC Sierra All Terrain Concept made its debut in Detroit, we were granted an interview and obtained video footage of it at the 2011 Chicago Auto Show.