Sierra All Terrain HD Concept 1

GMC has come up with the Sierra All Terrain HD Concept, essentially an exploration of how you can get a heavy-duty truck to become a stylish off-road mule. The rugged 4WD beast, which will debut in Detroit next month, sits on a 2011 Sierra HD chassis, and features a production 6.6 litre Duramax V8 turbodiesel pot offering 397 hp at 3,000 rpm and 1,037Nm of torque at 1,600 rpm, mated to an Allison 1000 six-speed automatic transmission powertrain.

Elsewhere, things have been reworked – the vehicle gets increased ground clearance by 3 inches and a wider track, as well as greater approach and departure angles. Additional off-road elements custom front upper and lower control arms, specially constructed Fox off-road shocks with remote fluid reservoirs integrated in the wheel house liners to prodvide additional compression damping and more controlled rebound, front and rear jounce shocks, electronic front stabiliser bar disconnection and 35-inch-tall BFGoodrich KM2 mud terrain tyres mounted on 20-inch machined aluminium wheels.

Sierra All Terrain HD Concept 2

A full composite underbody protection system shields the vehicle’s transmission, drivetrain, fuel tank, exhaust system and axle differentials. It starts with the front bumper, which rolls beneath the truck and leads to a composite, integral belly pan that covers a front suspension skid plate. Protective covers are also mounted beneath the driveline components, while the front and rear differentials feature direct-mounted skid plates.

Exterior-wise, there’s plenty of high-intensity LED lighting on this concept – the suitably-equipped headlamps, tail lamps and fog lamp lighting is mounted in impact-resistant composite housings and features edge-lit illumination, and there’s also LED floodlights for the cargo bed and assist steps.

Sierra All Terrain HD Concept

Speaking of the rear, the cargo box features lockable, lighted storage compartments, and a composite bed liner with a unique “circuit board” pattern provides a protective cover for the bed. The cargo bed – as well as the cab – features motorised, deployable assist steps to make it easier to enter and exit the vehicle.

Inside the Iridium Metallic-finished truck, two-tone dark gray leather seats, matched with embossed carbon fibre-style leather on the seating surfaces and red contrast stitching, are joined by a mix of accent details such as stainless steel mesh and satin chrome.

Gallery after the jump.

[zenphotopress number=999 album=1817]