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GMC Sierra All Terrain HD Concept Takes Heavy-Duty Capability To New Ground


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GMC Sierra All Terrain HD Concept Takes Heavy-Duty Capability To New Ground


DETROITThe GMC Sierra All Terrain HD concept is an exploration of heavy-duty truck capability combined with greater off-road versatility. It is highlighted by a bold exterior design, enhanced all-terrain suspension and premium details expected of a GMC – all designed to enable greater access to off-road destinations.

The new 2011 Sierra HD underpins the All Terrain HD concept, with a modified, production-based 4WD chassis and the Duramax diesel/Allison 1000 six-speed powertrain. The enhanced suspension and unique body dimensions, including increased ground clearance and wider track, as well as greater approach/departure angles, deliver off-road capability while maintaining HD levels of payload and trailering capacity.

"The Sierra All Terrain HD concept takes GMC's outstanding new HD platform to the next level, marries it to the legendary Duramax diesel/Allison transmission, and provides a heavy-duty expression of GMC's premium All Terrain package," said Lisa Hutchinson, GMC product marketing director. "It delivers the exceptional capabilities of the Sierra HD – hauling, towing and performance – and applies them to the toughest driving environments. It's the ultimate professional-grade tool for construction crews, ranchers and adventurers whose activities aren't limited by where the pavement ends."

The Sierra All Terrain HD features a unique five-foot, eight-inch Crew Cab/short box body configuration that supports a wheels-at-the-corners proportion. Shorter in overall length than production Sierra HD models, the concept's dimensions contribute to greater approach/departure angles. Additional off-road elements include:

  • Wider, 73-inch (1,853 mm) track for greater stability
  • Approximately 3 inches (76 mm) greater ground clearance
  • Custom front upper and lower control arms
  • Specially constructed Fox off-road shocks with remote fluid reservoirs (integrated in the wheel house liners)
  • Front and rear jounce shocks
  • Electronic front stabilizer bar disconnection
  • 35-inch-tall BFGoodrich KM2 "mud terrain" tires mounted on 20-inch machined aluminum wheels
  • Full composite underbody protection.

"The capability-enhancing attributes of the Sierra All Terrain HD build on the already outstanding capabilities offered in the all-new production Sierra HD trucks," said Hutchinson. "Although it is strictly a concept, it is a pretty realistic one."

Purposeful design


From every angle, the All Terrain HD looks the part of a dedicated off-road performer, with bold, accentuated features complemented by a wide stance and tall profile.

Streamlined bumpers are designed to enhance approach/departure angles and incorporate frame-mounted recovery hooks – with integrated skid plates. A large, airflow-optimized grille maximizes cooling in tough conditions, while a forced-induction hood delivers more air to the Duramax diesel engine.

"The design of the All Terrain HD is an expression of its capabilities – strong, functional and absolutely professional grade," said Carl Zipfel, design manager. "We're excited about the design elements and exploring how they could apply to future GMCs."

Large fender flares stretch away from the body to cover the 35-inch-tall BFGoodrich tires. At the rear, the cargo box features lockable, lighted storage compartments, along with a number of tie-down cleats, including a pair in the bed floor and two on each side of the bed. A non-slip rubber pad is used on the tailgate, while two special compartments inside the cargo box provide access to a 110-volt power outlet and air compressor. A composite bed liner with a unique "circuit board" pattern provides a protective cover for the bed.

Motorized, deployable assist steps for the cab and cargo bed make it easier to enter and exit the All Terrain HD, while maximizing ground clearance during off-road driving. It also incorporates a number of industrial-grade lighting elements to provide greater visibility for safer driving where stars may be the only other source of illumination. The lighting details include:

  • High-intensity LED headlamp, taillamp and fog lamp lighting mounted in impact-resistant composite housings and featuring edge-lit illumination
  • High-intensity LED park and turn signal lamps
  • Smooth-appearance front marker lamps integrated behind the top edge of the windshield glass
  • Integrated center high-mounted stop lamp and rear marker lights mounted at the top edge of the rear window glass
  • LED floodlights for the cargo bed and assist steps.

The All Terrain HD is painted Iridium Metallic – a dark charcoal color that reveals a reddish, anodized inflection when viewed from certain angles. It complements other anodized and satin-metal finishes on the exterior, which give the truck a more precise and functional appearance.

The interior matches the exterior aesthetic, with premium appointments and increased functionality, including enhanced lighting. It conveys solidity and precision, blending accent details such as stainless steel mesh and satin chrome with an amplified expression of the All Terrain's premium features. Two-tone dark gray leather seats, matched with embossed carbon fiber-style leather on the seating surfaces, have red contrast stitching. Additional leather-wrapped interior features include the steering wheel, instrument panel and center console.

A new navigation radio is also featured on the Sierra All Terrain HD concept and previews future radios to be offered in GMC vehicles. An integrated 80-gig hard drive contains map data for the navigation system. It eliminates the need for a map disc and provides greater storage of music from portable devices. It also features DVR-style "time lapse playback," which allows up to 20 minutes of recording/playback from the AM/FM/XM radio stations.

All Terrain chassis and suspension


Based on the chassis of the 2011 Sierra HD trucks, the All Terrain HD features a fully boxed steel frame with exceptional strength and torsional stiffness. It incorporates the production models' new independent front suspension and asymmetrical rear leaf-spring suspensions, but with a wider 73-inch (1,853 mm) track (front and rear) that enhances stability during off-road and highway driving. A production Sierra 2500HD has front and rear tracks of 68.8 inches (1,748 mm) and 67.3 inches (1,709 mm), respectively.

An increased ride height provides greater ground clearance of 21.1 inches (536 mm) at the rockers and 11.8 inches (300 mm) at the skid plates, while specialized Fox off-road shocks deliver exceptional damping on tough terrain. They were created specially for the All Terrain HD, with specific valving. The shocks feature visible, remote fluid reservoirs – connected to the shock bodies via custom hoses – mounted in the wheel house liners and are matched with front and rear jounce shocks. They add additional compression damping and more controlled rebound, which helps increase control, stability and handling.

The All Terrain HD also features electronic disconnection of the front stabilizer bar, which enables greater crawling capability on rocky terrain. The driver simply pushes a button inside the cab to disconnect it from the front suspension.

Custom upper and lower control arms for the front suspension are designed to work with the Fox off-road shocks and jounce shocks, while supporting the greater ground clearance and ride height. They contribute to the wider track, as do the aggressive 20-inch machined aluminum all-terrain wheels. The wheels are deep, with six split-spoke elements, and are constructed in a reverse drop-flange method that ensures optimal strength. They also feature a mix of satin chrome and anodized aluminum finishes, which provide durability and a premium appearance that complements the body's Iridium Metallic color.

A full composite underbody protection system shields the All Terrain HD'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. The rear bumper is integrated with the rear skid plate.

Powertrain details

The Sierra All Terrain HD concept is propelled by the new, production 6.6L Duramax turbo-diesel V-8 and Allison 1000 six-speed automatic transmission powertrain combination offered in the 2011 Sierra HD trucks. The Duramax is rated at 397 horsepower (296 kW) and 765 lb.-ft. of torque (1,037 Nm).

The powerful 6.6L Duramax is more fuel-efficient – with up to 11-percent greater fuel economy than previous versions – and reduces NOx emissions by up to 63 percent. The powertrain's efficiency is assisted by the Allison 1000 transmission, which requires less engine power to funnel torque to the axles. It also incorporates a "smart" exhaust brake feature that helps save wear on the brakes on downhill grades, a feature available on production Sierra HDs.

With the same proven powertrain as production Sierra HD trucks, the All Terrain HD delivers comparable hauling and towing capabilities, including:

  • Estimated payload capacity of 2,700 pounds (1,225 kg)
  • Estimated conventional towing capacity of 13,000 pounds (5,896 kg)
  • Estimated fifth-wheel towing capacity of 15,600 pounds (7,076 kg).

The Sierra All Terrain HD also features four-wheel drive, with automatic locking front and rear differentials, while the 14-inch, four-wheel disc brake system from the production Sierra HD provides the stopping power for this unique off-roader.

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First Look: GMC All Terrain Sierra HD Concept

Taking on the big guys?

by Mike Levine on Dec.16, 2010

The GMC Sierra All Terrain HD concept will make its world debut at the North American International Auto Show in Detroit.

Could GMC add a halo off-road truck to its full-size pickup lineup? The diesel-powered GMC Sierra All Terrain Heavy Duty Concept — which will debut next month at the 2011 Detroit auto show — points to how the “professional grade” brand thinks it might deliver a credible competitor to the Ford F-150 SVT Raptor and the Ram 2500 Power Wagon in the current or next-generation Sierra HD.

The light-duty Raptor and heavy-duty Power Wagon are two of the most capable off-road pickup trucks ever to jump or climb off the showroom floor. We love both because these purpose-built rigs can go places and do things off pavement that would kill lesser trucks within yards of the trailhead. The Raptor flies across the desert at high speed, like a Baja trophy truck, while the Power Wagon can rock crawl over the toughest terrain you’ll find in Moab.

But these traits make an apples-to-apples comparison of the trucks difficult because their off-road strengths lie at opposite ends of the wheeling spectrum. This is where GMC smells opportunity.

The short-box crew-cab Sierra All Terrain HD threads the needle between the half-ton Raptor and three-quarter-ton Ram 2500 Power Wagon by carving a new niche that blends the off-road prowess and features of the Ford and Ram trucks with a few new innovations.

The Ford F-150 Raptor is one of several intended targets should GMC put the Sierra All Terrain HD Concept into production.

As with all off-road pickups, the heart of the All Terrain HD is its suspension. The concept’s running gear makes good use of the Sierra’s overhauled box ladder frame, shocks, springs and axles that were introduced for the 2011 model year.

“The capability-enhancing attributes of the Sierra All Terrain HD build on the already outstanding capabilities offered in the all-new production Sierra HD trucks,” said Lisa Hutchinson, GMC product marketing director. “Although it’s strictly a concept, it’s a pretty realistic one.”

But some heavy-duty off-road users have criticized GM’s HD pickups for their torsion bar independent front suspension instead of a coil spring solid front axle, like Ford’s and Ram’s heavy-duty pickups use. An independent front suspension generally provides better ride comfort on- and off-road, which the light-duty Raptor uses for high-speed desert running. A solid front axle allows higher ground clearance and superior articulation — for low-speed rock crawling — which the Power Wagon excels at.

The All Terrain uses independent front suspension to its advantage. For improved off-road stability, the standard A-arms have been replaced with custom double-wishbones and offset wheels that give the Sierra a 73-inch track up front — 4.2 inches wider than the current Sierra HD and nearly identical to the Raptor’s 73.6-inch track.

The All Terrain’s rear track is also 73 inches from a stock rear axle and offset wheels. Ram Power wagon’s track is 68.3 inches in front and 68.2 inches in back.

An independent front suspension isn’t the only thing the Raptor and All Terrain HD have in common. They also share Fox Racing internal bypass shocks, though instead of piggyback reservoirs in back, the Sierra has remote reservoirs (for improved capacity and cooling) integrated into the truck’s wheel wells at all four corners.

If GMC wanted to get Ford’s attention, this should do it. Fox’s shocks are the key components that give the Raptor such awesome wheel travel at high speeds off-road.

Racing’s internal bypass technology is slick and maintenance-free. Instead of placing the oil routers outside the shocks, Fox sealed them inside the main tube so that they can’t be adjusted. The valves have been replaced with very small gates, precisely placed for optimal damping in all conditions. Hardcore off-roaders might not like this setup, but it solves several potential issues both for GMC and for less-obsessive desert-running enthusiasts. There are no external bypass tubes to be damaged by offroad debris striking them; there are no worries about check-valve durability; and the shocks can be tuned specifically to the Sierra All Terrain’s off-road character.

In the Sierra, Fox’s long-travel dampers add 2 inches more travel up front (11 inches total) and 3 inches in the rear (11.75 inches total) over the Sierra’s stock monotube shocks.

While Ram doesn’t offer Fox shocks for the Power Wagon, Chrysler Mopar performance parts division will also feature Fox Shocks as part of its aggressive Ram Runner dealer-installed off-road package for the light-duty Ram 1500.

We wouldn’t be surprised if this latest Fox development effort causes a major rift with Ford, which brought prominence and high-volume production expertise to Fox in OEM off-road applications.

The All Terrain HD also borrows a cool trick for its front suspension from the straight axle Power Wagon. The Ram features a front sway bar disconnect system that increases wheel travel and articulation to climb over tall obstacles. The Sierra All Terrain also has an electronic front stabilizer bar disconnect.

A slick new piece of suspension kit introduced on the Sierra All Terrain HD that neither the Raptor nor Power Wagon offer are front and rear jounce shocks. Jounce shocks, in contrast to common urethane jounce bumpers that pickup trucks use to cushion overload situations, work by providing secondary compression and rebound support over tough terrain to prevent the truck from bottoming out. Instead of oil, they use nitrogen gas and lack internal valves for simplicity and smooth damping operation.

The Sierra All Terrain’s jounce shocks were co-developed with Light Racing. The All Terrain HD has electronic locking differentials in the front (like Power Wagon) and rear (like Power Wagon and Raptor) axles for maximum traction in slippery spots. Even if the All Terrain HD Concept never makes it to production, we expect we’ll see a similar front e-locker option available in future GM full-size pickups based on lessons learned from the discontinued Hummer brand and the extra capability the feature brings to a truck.

For improved ground clearance, the Sierra All Terrain’s ride height has been raised by about 3 inches over the stock Sierra’s ride height. It’s 21.1 inches at the rocker panels and 11.8 inches at the skid plates.

Contributing to the lift are aggressive 20-by-9.5-inch six-spoke custom 8-lug wheels with 35-inch-tall BFGoodrich 325/60R20 tires.

Form follows function when it comes to the GMC Sierra All Terrain’s exterior design.

Carl Zipfel, the lead designer for the Sierra All Terrain, has designed trucks at GM for more than a decade, including some of the coolest concepts and production rigs such as the GMC Terradyne, Terra4 and Hummer H2 and H3 trucks.

“The design of the All Terrain HD is an expression of its capabilities — strong, functional and absolutely professional grade,” Zipfel said. “We’re excited about the design elements and exploring how the could apply to future GMCs.”

Though the Sierra All Terrain is based on the current GMC Sierra HD, we believe it hints at styling elements that will be found in the next-generation Sierra pickups expected around 2013.

The prominent front end features an in-your-face three-bar grille and chrome surround that reminds us a bit around the top of the first-generation GMC Yukon Denali.

The lower portion of the grille blends smoothly into the front bumper and integrated skid plate. The hood cleanly drops the center louver found in today’s Sierra HD and replaces that plastic island with two integrated functional hood vents to help bleed heat from the engine bay. Instead of a Coke-bottle shape like the Raptor has to cover its wide stance, the Sierra All Terrain uses massive flares over the wheel housings. The side doors are shared with the current Cadillac Escalade, and auto-folding side steps extend and retract to help with ingress and egress.

The Sierra’s extra-short 5-feet-8-inch cargo box draws inspiration from the light-duty Ram 1500’s optional RamBox side-saddle storage, with its own built-in compartments that don’t eat into valuable open bed space.

When it comes to off-roading, it’s all about keeping the shiny side up, but to protect the bottom of the truck from brutal terrain, the All Terrain has a composite underbody shield that covers the powertrain, fuel tank, exhaust and diffs. The rear bumper has an integrated skid plate that aids the truck’s departure angle while blending together.

One of the areas most in need of improvement in the current GMC Sierra HD is the cabin space. It looks dated compared with the Ford and Ram interiors.

The Sierra All Terrain HD sticks with the current interior instead of previewing the next-gen Sierra but it addresses some of our cockpit gripes by using new premium materials, such as stainless steel mesh and satin chrome. Two-tone leather seats feature slick carbon fiber patterns embossed in the skin and red stitching around the seams. The instrument panel is also wrapped in leather.

A new navigation radio previews the same head unit that will be offered in future GM vehicles, so expect to see this in the next-gen Sierra and Chevy HD pickups. It uses an 80-gigabyte hard drive to store map data and has a DVR-style “time-lapse playback” that allows up to 20 minutes of content recording and replay from terrestrial and satellite radio stations.

If there’s one thing that heavy-duty off-road enthusiasts have wished for in powertrains, it’s a diesel engine for awesome low-end torque while rock crawling.

In 2008, Mopar debuted the Dodge Ram Diesel Power Wagon at Easter Jeep Safari in Moab, Utah, but that concept has remained just that because the Power Wagon’s integrated Warn winch blocks airflow to the 6.7-liter Cummins inline-six-cylinder’s turbo intercooler. The production Ram Power Wagon has a strong 5.7-liter Hemi V-8. Setting the Sierra All Terrain apart from both Power Wagon and the Raptor is its 6.6-liter Duramax V-8 diesel and six-speed Allison automatic transmission. The powertrain is virtually identical to the 397-horsepower, 765 pounds-feet of torque DMAX diesel offered in today’s GM HD pickups.

When the Duramax diesel is combined with the extra-strength off-road suspension, GMC says the Sierra All Terrain hangs onto its current towing ratings instead of sacrificing them for extra off-road capability. It’s estimated to be able to tow up to 13,000 pounds conventionally — about 3,000 pounds more than the gasoline-powered Raptor and Power Wagon pickups — and up to 15,600 pounds with a fifth wheel hitch.

Payload capacity is estimated at 2,959 pounds.

There’s little doubt that General Motors has missed an opportunity in off-road. While GM was trying to figure out what to do with the radioactive Hummer brand, Ford’s gamble on the go-fast F-150 SVT Raptor has paid huge dividends for enthusiasts and the company’s image. At the same time, a handsome styling update last year for the Ram 2500 Power Wagon brought new interest and popularity to Chrysler’s tough ground pounder.

The GMC Sierra All Terrain HD could be an excellent chance at redemption, but we wonder if there’s a market for a diesel-powered HD off-road halo truck that could probably cost more than $65,000.

At the 2009 SEMA expo in Las Vegas, Chevy showed a concept light-duty gas-powered supercharged Silverado ZR2 that also featured superior off-road capability over current production GM trucks, but nothing has been heard about that concept since. The GMC Sierra is GM’s second signal that it wants a piece of the off-road market. We’ve heard strong rumors of a revised V-8 gas engine for GM’s HD pickups possibly arriving before new sheet metal and interior. Putting a credible gas engine in the Sierra AT HD would reduce its price point to probably around the low $50,000s. At that point, it becomes a credible contender to the Raptor and Power Wagon.

According to Mike Tulemello, vehicle line director for GM fullsize trucks, a pickup like the All Terrain could be produced quickly by working with a second-stage manufacturer after rolling off the production line.

We hope GM takes a risk and enters unfamiliar terrain by producing a new HD model similar to the GMC Sierra All Terrain HD Concept. It’s already identified a new niche on the off-road map.



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Interesting. I wonder if this shows some of the aspects we might expect in the coming refresh of the Sierra.

but what from this, other than bigger flares smaller headlights and a questionable grille styling is different from the regular truck?

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but what from this, other than bigger flares smaller headlights and a questionable grille styling is different from the regular truck?

The regular 2011 truck, or the regular truck from the year this (if it does) debut ??

Because this shares nothing external with the current truck, except perhaps the cab (tho the doors are different).

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Yeah the Raptor is way more badass, and more than just a lift.

Raptor looks like a serious Baja desert runner. It does the SVT name proud. This just looks like some blinged out monster truck you'll find parked outside a McMansion in Orange County, CA.

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The Raptor is a great truck for who it is ment for. I like it but many people don't. We tyhe few we have around here not everyone is impressed with the truck as they are just not into it and don't know what Fox Shocks are.

This truck is for people who don't do the Baja every day. I don't know well it drives off road but the engine look fine.

At least it does not have orange seats. I would love to see a matte black editition of the Raptor. Call it Night Op's.

Edited by hyperv6
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but what from this, other than bigger flares smaller headlights and a questionable grille styling is different from the regular truck?

Not picking on you in any respect, but how well do you know the current Sierra design? I know it very well because it's the one GM vehicle I'd kill to own. This 2011 Sierra All Terrain HD Concept is totally different from the current generation Sierra. The bed shows the side boxes that the 2000 GMC Terradyne introduced (and the Dodge Ram put into production), the tailgate is an all-new stamping (just love the BIG GMC lettering in the middle of the tailgate, and hope it makes it to production), the grille design is similar to the GMC Granite CUV and Pickup AND the Terrain's, doors are all-new stampings, hood, fenders... this truck is definitely not a current generation Sierra dolled-up for the show circuit.

For those of you who remember the 1998 GMC Sierra Show Trucks, the ACE and DUECE, they were blinged-out versions of the upcoming pickups for 1999. See for yourself:

1998 GMC Sierra ACE (show truck):


1999 GMC Sierra Extend Cab (production):


1998 GMC Sierra DUECE (show truck):


1999 GMC Sierra Regular Cab Sportside:


I think this 2011 GMC Sierra All Terrain HD Concept is a heavy modified production truck (lift kit, custom rims & tires, etc)

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New GM? GMC's off-road monster truck concept arrives

08:24 AM


If you think the new General Motors doesn't look like the old General Motors, take a gander at the new GMC Sierra All Terrain HD off-road truck concept. It will be rolled out at the Detroit auto show next month.

This is one huge, Hummer-like truck. We love the grille that becomes a front-end skid plate. It's apparently meant to take down the Ford F-Series Raptor, which is just as brawny.

Underneath all that machismo, GM swears there is a 2011 Sierra HD pickup in there somewhere. The concept is built on its chassis with a Duramax engine/Allison six-speed transmission built in. Naturally, it has a beefed up suspension to handle the biggest of bumps.

"The Sierra All Terrain HD concept takes GMC's outstanding new HD platform to the next level, marries it to the legendary Duramax diesel/Allison transmission, and provides a heavy-duty expression of GMC's premium All Terrain package," said Lisa Hutchinson, GMC product marketing director.

The Sierra All Terrain HD features a 5-foot, 8-inch crew cab and a short box in back. And the engine?

It is powered by a 6.6-liter Duramax turbo-diesel V-8 and Allison 1000 six-speed automatic transmission powertrain combination offered in the 2011 Sierra HD trucks. The Duramax is rated at 397 horsepower and an astounding 765 foot-pounds of torque.

Lest we carry the old GM image too far, GM would like to point out the giant engine gets 11% better fuel mileage than its previous version and 63% fewer carbon emissions. It can tow 13,000 pounds.




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This 2011 Sierra All Terrain HD Concept is totally different from the current generation Sierra. The bed shows the side boxes that the 2000 GMC Terradyne introduced (and the Dodge Ram Chevrolet Avalanche/Cadillac Escalade EXT put into production),

Not picking on you... but fixed that for you. They are just larger versions of what was put into production on the Avalanche.

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Not picking on you... but fixed that for you. They are just larger versions of what was put into production on the Avalanche.

Wasn't Ram Box the first of those? Never seen anything like that on an Avalanche.

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