2011 GMC Sierra Denali HD – Click above for high-res image gallery

Not even a month ago, at the end of our post on the 2011 Ford Super Duty engine specs, we wrote: "General Motors, there's a big ass ball in your court." Someone at GM has apparently grabbed their big ass racket and said, "Oh, I got this...", then smacked the ball right back into play. The Ford's measurements 390 horsepower, 735 pound-feet of grunt. The General has just announced that its 6.6-liter Duramax turbo diesel has 397 horsepower and 765 lb-ft. of torque, a jump of 32 horsepower and 105 lb-ft. over the previous Duramax.

A closer look at the numbers does reveal some give-and-take, however. The Ford's maximum tow rating is 21,600 pounds, while GM's is 20,000 pounds. And while not exactly engine related, the Ford truck also has a higher max payload than the GM twins. Still, the RenCen pickups take the power crown, and the new Duramax is more efficient than the previous one – GM didn't put a specific mileage number to it, but claims 680 miles of highway going possible from the 36-gallon tank. You'll find GM's press release on the new engine after the jump.

In related news, GM has released the first image of its GMC Sierra Denali HD pickup, mechanical and sheetmetal twin of the Chevrolet Silverado HD. There's an additional press release after the jump for it as well.

So... anyone else want to take a swing at that even bigger ass ball?


Related Gallery2011 GMC Sierra Denali HD

[Source: General Motors via PickupTrucks.com]
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New 2011 Chevrolet Silverado Heavy Duty Trucks Deliver Best-In-Class Diesel Torque And Horsepower

* New 6.6L Duramax turbo diesel rated at 397 hp (296 kW) and 765 lb.-ft. of torque (1,037 Nm)
* Segment-best diesel power complemented by up to 11-percent improved highway fuel economy and up to 63-percent reduced NOx emissions
* Up to 680-mile (1,090 km) driving range with Duramax engine in pickups
* Standard small-block 6.0L gas V-8 delivers 360 hp (268 kW)

PONTIAC, Mich. – Chevrolet's new 2011 Silverado 2500HD and 3500HD pickups deliver the segment's best diesel power. Their new, optional 6.6L Duramax turbo-diesel V-8 is rated at 397 horsepower (296 kW) at 3,000 rpm and 765 lb.-ft. of torque (1,037 Nm) at 1,600 rpm – an improvement of 32 horsepower (24 kW) and 105 lb.-ft. of torque (142 Nm) over last year's engine.

"Segment-leading power is great, but it's not the only thing that makes the new Duramax a winner," said Gary Arvan, Duramax chief engineer. "We designed the engine to make that power with less fuel and fewer emissions, while also increasing its durability."

A slightly different version of the 6.6L Duramax is offered in Silverado HD chassis and box-delete models. It is based on the same improved architecture and includes most of the same features as the pickup version, but is engineered to meet federal certification standards for incomplete vehicles, including the incorporation of a robust EGR system. It is rated at 335 horsepower (249 kW) at 3,100 rpm and 685 lb.-ft. of torque (928 Nm) at 1,600 rpm.

Among the 2011 6.6L Duramax turbo diesel's new and enhanced features are:

* Main bearing profiles changed to enhance oil film thickness
* Oil pump flow increased for more pressure at low speeds
* A revised turbocharger oil circuit for increased pressure at the turbo and faster oil delivery
* Connecting rod pin ends modified to provide increased piston support
* New, higher-strength piston design
* A new 30,000-psi (2,000 bar) piezo-actuated fuel injection system – capable of operating on ASTM grade B20 biodiesel – ensures more precise fuel delivery, improving emission performance
* An EGR cooler bypass reduces high-mileage soot deposits in the cooler and EGR circuit (pickup versions only).

The more powerful 6.6L Duramax is also more fuel-efficient – up to 11-percent greater highway fuel economy than the outgoing model – reduces NOx emissions by up to 63 percent and helps enable greater towing ratings. Silverado 3500HD equipped with a fifth wheel hitch can tow up to 20,000 pounds (9,072 kg). The increased fuel efficiency, combined with a new, 36-gallon (136 L) fuel tank, provides up to 680 miles (1,090 km) of highway driving between fill-ups.

With nearly 1.3 million Duramax diesel engines put into operation since its launch in 2000, no other automaker has as much diesel engine development experience for meeting the demands of the heavy-duty truck customer.

Strong small-block 6.0L V-8

The standard engine in Silverado HD trucks is the Vortec 6.0L small-block V-8, which is enhanced for 2011 with greater idle refinement. It is rated at 360 horsepower (268 kW) at 5,400 rpm and 380 lb.-ft. (515 Nm) at 4,200 rpm in Silverado 2500HD and 3500HD pickup models. In chassis cab and box-delete models, as well as pickups with a GVWR greater than 10,000 pounds, it is rated at 322 horsepower (240 kW) at 4,400 rpm and 380 lb.-ft. (515 Nm) at 4,200 rpm.

Approximately 90 percent of the Vortec 6.0L's peak torque is available by only 2,000 rpm and excellent fuel economy is enabled by the engine's low-friction OHV configuration and cam phasing. The state-of-the-art small-block architecture of the Vortec 6.0L – known commonly as the "LS" family – delivers great strength, smoothness and durability.

Whether equipped with the 6.6L Duramax or the small-block 6.0L, all 2011 Silverado models work under the best warranty coverage in America – a five-year/100,000-mile limited powertrain warranty, plus roadside assistance, courtesy transportation and other features that provide assurance that Chevrolet backs its trucks for everything the road offers.


Sierra Denali HD Leads New 2011 Sierra Heavy-Duty

ST. LOUIS, Mo. – GMC today announces the new 2011 Sierra Denali HD, the first offering of the exclusive Denali line on a heavy-duty GMC pickup. The Sierra Denali HD leads a comprehensively redesigned lineup of 2011 Sierra 2500HD and 3500HD trucks that go on sale in early summer – including the most powerful diesel engine in the segment.

Sierra HD's new 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.

"The new Sierra Denali HD is the latest expression of GMC's Denali philosophy of blending capability with premium features and styling," said Lisa Hutchinson, GMC product marketing director. "It is a premium tool that offers many comfort and infotainment features, along with a maximum towing capacity of 15,600 pounds with the segment's most powerful diesel – that's enough to tow a 34-foot-long, three-axle travel trailer."

The 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 balance of the new 2011 Sierra HD lineup is identified on the outside by new, three-bar grilles and powertrain-badged louvered hoods, along with a revised, full-width chrome steel front bumper and a new family of 17-, 18- and 20-inch wheels. It's beneath the skin, however, where they are truly separated from their predecessors – and the competition. Highlights include:

  • Increased towing capability (20,000 lbs./9,072 kg) and payload (6,335 lbs./2,873 kg) supported by all-new fully-boxed, high-strength-steel frames and strong suspensions for maximum capability and exceptional ride characteristics
  • Five of the 12 3500HD models offer a payload capability greater than 6,000 pounds vs. Ford Super Duty's single model greater than 6,000 pounds
  • Thirteen of the 22 2500HD models offer a payload capability greater than 3,100 pounds vs. Ford Super Duty's single model greater than 3,100 pounds
  • 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
  • Larger gas tank and fuel economy improvements allow up to 680 miles (1,090 km) between fill-ups with the 6.6L Duramax turbo diesel
  • All-new "smart" exhaust brake feature provides greater control on grades and reduced brake pad wear
  • An array of control features, including trailer sway control, integrated trailer brake control, hill start assist, automatic grade braking, intelligent brake assist and larger brakes
  • Purposeful technology, including available mobile WiFi, USB connectivity, Bluetooth connectivity, XM Satellite Radio, OnStar 9.0 and navigation.

"GMC has been one of the industry's strongest truck brands for more than 100 years, and we back the 2011 Sierra HDs with a comprehensive five-year/100,000-mile powertrain warranty that provides the best coverage in America," said Hutchinson. "From the segment-best diesel power to the segment-best warranty, these trucks deliver strength and peace of mind on all fronts."

Following are details of the new and redesigned product features of the Sierra Denali HD and the other Sierra 2500HD and 3500HD models.

The Sierra HD lineup brings greater capability.

The details: Depending on the model, Sierra HD models offer:

  • Increased fifth-wheel towing capacity of 20,000 pounds (9,072 kg)
  • Conventional towing capacity increases up to 23 percent, with a maximum of 16,000 pounds (7,272 kg)
  • Improved payload capability of 6,335 pounds (2,873 kg) on a complete vehicle
  • Gross Combined Weight Rating increases to 27,500 pounds (12,500 kg)
  • Gross Vehicle Weight Ratings increases up to 17 percent to 13,000 pounds (5,909 kg)
  • Front Axle Weight Rating increases by up to 25 percent to 6,000 pounds (2,721 kg)
  • Snow plow capability for all 4WD cab configurations.

"You can see by the ratings numbers that the Sierra HD lineup is more capable, but the trucks are also better performers in the intangible qualities that bond owners with their trucks," said Rick Spina, vehicle line executive. "They accelerate quicker – especially when fully loaded – stop more confidently and deliver a smooth, quiet driving experience that you have to experience to fully appreciate."

The new 2011 Sierra Denali pairs capability with premium features.

The details: 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.

On the capability front, the Sierra Denali has a gross vehicle weight rating (GVWR) of 10,000 pounds (4,536 kg), a payload capacity of 2,959 pounds (1,342 kg) and a maximum trailering rating of 15,600 pounds (7,076 kg) with a fifth-wheel hitch. The maximum conventional hitch trailering rating is 13,000 pounds (5,897 kg).

Engineers developed 11 all-new, fully boxed frame assemblies to improve durability and ride characteristics and support increased capabilities.

The details: 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 hydroformed. 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. Also, larger engine and transmission mounts, coupled with a 125-percent-stiffer front frame structure, provide greater vibration control, while hydraulic body mounts are incorporated under the cab section on extended and crew cab models for a more isolated feel inside. Engineers addressed common customer and aftermarket uses when designing the new frames, including adding access holes to the rear frame section to enable easier installation of fifth-wheel/gooseneck-style hitches. Also, the frame-mounted hitch for conventional trailering is stronger, with a box-tube design. It supports up to 16,000 pounds (7,257 kg).

Sierra HDs feature a new, stronger independent front suspension – enabling snow plow installation on all 4WD models.

The details: 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. The new lower control arms are made of precision-machined cast iron to handle the greater loads. Five different torsion bar rates support five different front gross axle weight ratings (a single torsion bar was previously used for all models). This helps stabilize the range of trim heights of various models under load, while enhancing appearance, handling, durability, tire wear and alignment. The trim height is adjusted on each bar via a single bolt, easily allowing the height to be changed to account for the weight of a snow plow or other accessories. The Sierra HD front suspension now uses a pair of urethane jounce bumpers on each side, instead of one, for improved load management; and there's a new upper shock mount attachment design that's positively connected to the frame with two fasteners. This design eliminates squeaks and clunks, while supporting higher load capability and increased durability.

COMPETITIVE FACTS: Compared to competitors' beam-axle front suspensions, the Sierra's independent front suspension provides a better ride, more accurate trim height control (with fewer parts) and greater flexibility to adjust the alignment for weight and tire sensitivity.

A new asymmetrical leaf-spring rear suspension supports greater loads.

The details: Matching the Sierra HD's greater strength and capability is a rear suspension designed to support greater loads. It features a new, larger asymmetrical leaf-spring design that also contributes to improved ride and handling characteristics. The asymmetrical design is derived from unequal front and rear spring half lengths, which minimize axle hop and enhance traction control efficiency. 2500HD models feature a two-stage leaf-spring design, while 3500HD models have a three-stage design. All models feature 3-inch-wide (76 mm) leaf springs that are 20-percent wider than previous models. The larger leaf-spring design supports increased rear gross axle weight ratings across the board. On the 2500HD models, the rating is 6,200 pounds (2,818 kg) – up from 6,084 (2,765). On 3500HD models, the rating increases to 7,050 pounds (3,204 kg) on single-rear-wheel models and 9,375 pounds (4,261 kg) on dual-rear-wheel models – the latter representing a nearly 14-percent increase over the previous 8,200-pound (3,727 kg) rating.

Sierra HDs deliver a more refined driving experience, with more capable ride, handling and steering.

The details: Longer wheelbases – ranging from 133.6 inches (3,395 mm) to 167.7 inches (4,259 mm) – and wider front/rear tracks enhance the ride and handling characteristics of the Sierra 2500HD and 3500HD, giving them a greater feeling of smoothness and control. The longer wheelbases and wider tracks are complemented by the new, stiffer frames, new jounce bumpers, shock mounts and hydraulic body mounts to provide a solid, smooth and isolated driving experience. New shocks were specially valved to support the new trucks' weight ratings, while balancing excellent ride characteristics. Also enhancing the driving experience is a revised steering system designed to support the trucks' greater front gross axle weight rating. It includes a new, larger steering gear, power steering pumps and linkages. The pumps (different parts for gas and diesel models) deliver greater pressure for reduced steering effort in low-speed and parking maneuvers; they are also quieter. On some models, the new linkages feature a compliant joint added at the pitman attachment to enhance handling.

The new 6.6L Duramax turbo diesel delivers segment-leading torque and up to 63-percent lower NOx emissions; and is B20-capable.

The details: The workhorse Duramax 6.6L turbo diesel V-8 is more powerful and durable for 2011, delivering segment-best horsepower and torque – 397 horsepower (296 kW) at 3,000 rpm and 765 lb.-ft. of torque (1,037 Nm) at 1,600 rpm – lower emissions and B20 biodiesel capability that promotes a domestically produced renewable fuel. The new Duramax 6.6L features:

  • NOx emissions reduced at least 63 percent over 2010 models
  • Quieter operation
  • High-pressure (30,000 psi/2,000 bar) Piezo-actuated fuel system for greater fuel efficiency, improved performance and reduced emissions
  • "Smart" exhaust brake feature that enables controlled vehicle slowdown on downhill grades without actuating the brakes
  • Selective catalytic reduction after-treatment system using diesel exhaust fluid (DEF) injection to provide the best overall diesel characteristics and performance – with a range of about 5,000 miles (8,000 km) between DEF refills
  • Combustion and after-treatment have been optimized to provide about 700 miles (1,125 km) between diesel particulate filter regenerations – a 75-percent improvement over the previous system and a significant contributor to improved fuel efficiency, as the regeneration process requires additional fuel
  • B20 biodiesel capability for an alternative fueling option
  • Internal revisions that improve durability.

With nearly 1.3 million Duramax 6.6L engines produced since 2000, they have proven exceptionally durable and dependable. The internal elements that helped build its reputation are enhanced for 2011, including:

  • Main bearings' profiles changed to enhance oil film thickness
  • Oil pump flow increased for increased pressure at low speeds
  • Modified turbocharger oil circuit for increased pressure at the turbo and faster oil delivery
  • The connecting rods' pin ends are modified to provide increased piston support
  • New, higher-strength piston design that eliminates bushings to provide lower reciprocating weight
  • An EGR cooler bypass reduces high-mileage soot deposits in the cooler and EGR circuit.

COMPETITIVE FACTS: Compared with Ford Super Duty's urea-based system, Sierra HD's selective catalytic reduction after-treatment system delivers better overall diesel performance, with a range of about 5,000 miles (8,000 km) between DEF refills. Its optimized combustion and after-treatment process provides about 700 miles (1,125 km) between diesel particulate filter regenerations – a better capability than Ford's.

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 details: The enhanced Allison 1000 is strengthened to handle the higher torque capability of the new 6.6L Duramax engine, while also helping to improve fuel economy and provide seamless assistance with a new exhaust brake system. Greater efficiency is delivered through reduced "spin loss" – meaning, the transmission channels more of the engine's power to the axles, allowing it to do more with less fuel. 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. The six-speed configuration retains its two overdrive gears for optimal efficiency. Performance with the Duramax/Allison combination is also improved over previous models, with preliminary testing showing 0-60 mph times of less than 9 seconds and quarter-mile times of less than 16 seconds in 2500HD models. That's about 0.3-second and 0.5-second quicker, respectively, than previous models.

A strengthened Vortec 6.0L/Hydra-Matic 6L90 six-speed powertrain is standard in all models.

The details: The Vortec 6.0L gas V-8 with variable valve timing returns to the new Sierra HDs, along with a strengthened version of the Hydra-Matic 6L90 six-speed automatic transmission. This combination delivers excellent performance and efficiency, with a greater emphasis on low-rpm power. It is enhanced for 2011 with greater idle refinement.

The engine is rated at 360 horsepower (268 kW) at 5,400 rpm and 380 lb.-ft. (515 Nm) at 4,200 rpm in trucks with GVWRs up to 10,000 pounds. It is rated at an estimated 322 horsepower (240 kW) at 4,400 rpm and 380 lb.-ft. of torque (515 Nm) at 4,200 rpm in trucks with GVWRs greater than 10,000 pounds.

The 6L90 is enhanced for greater strength, smoothness and quietness via:

  • Adding four attachment bosses to the transfer case adapter (4WD models) for increased strength and smoother, quieter performance
  • Increasing the cross section size of the transfer case adapter for greater strength
  • Adding a new, stronger output shaft
  • Adding a new heat shield and vent hose.

COMPETITIVE FACTS: Ford's new Super Duty models share the same transmission between their gas and diesel engines. Sierra HDs' Allison 1000 and Hydra-Matic 6L90 transmission were developed for the specific horsepower, torque and operating range differences that distinguish the diesel and gas engines.

Brake feel and performance is greatly improved.

The details: The standard four-wheel disc system is completely revamped to deliver smoother, more immediate and confident-feeling performance. Four-wheel, four-channel ABS is standard on all single-rear-wheel models and a three-channel system is standard on dual-rear-wheel models. The front and rear rotors are larger in diameter – 14 inches (355 mm) – and width on all models to support their increased capacity, weight ratings and trailering ratings, while the calipers are stiffer and stronger. The hydroboost brake booster calibration is revised for reduced pedal effort, and the travel of the pedal is also revised for a more comfortable, confident feel. Larger wheel hub and bearing assemblies complement the new brake system, and the rear rotors attach to the wheel hubs for easier servicing.

Sierra HD's 'smart' exhaust brake feature provides greater control and reduces brake pad wear.

The details: A new standard feature on Duramax-equipped models is the "smart" exhaust brake. This driver-selectable feature uses the turbine control of the variable geometry turbocharger and the compression of the engine to generate backpressure, slowing the vehicle without applying the brakes. It is integrated with the cruise control feature and varies the braking to account for the grade and vehicle load. The exhaust brake allows for virtually effortless driving and towing, with seamless and quiet operation. It also helps prolong brake life and prevents overheating the brakes on long, downhill grades.

Comprehensive safety features and functional technologies include trailer sway control system and hill start assist.

The details: The 2011 Sierra 2500HD and 3500HD models have a comprehensive roster of safety features and functional technologies that include:

  • StabiliTrak electronic stability control system on all single-rear-wheel models
  • Larger, four-wheel disc brakes with standard four-wheel ABS
  • A new high-strength steel tubular frame cross member that enhances safety and improves crashworthiness
  • Seat pelvic/thorax and head curtain side air bags available on 2500HD
  • Available rear backup camera
  • Segment-exclusive OnStar 9.0
  • Trailer sway control system on all single-rear-wheel models
  • Hill start assist (standard on single-rear-wheel models)

The trailer sway control system provides an added measure of confidence when towing a trailer. The system senses conditions of trailer sway and intervenes with braking and/or reduced engine power to bring the trailer under control and keep it on its intended path. The system uses electric trailer brakes when a trailer is plugged into the standard wiring harness of the truck and its performance requires no input from the driver. The hill start assist system is automatically engaged when sensors detect the vehicle is on a grade of about 5 percent or greater. It holds the brakes for about 1.5 seconds or until the gas pedal is pressed, preventing rollback – it is particularly effective when towing, giving the driver time to switch from the brake pedal to the gas pedal without rolling.

The GMC Sierra HD lineup is broader than ever.

The details: For 2011, the Sierra heavy-duty lineup expands to include 11 2500HD models and eight single- and dual-rear-wheel 3500HD models – including a new 3500HD Crew Cab with a 6.5-foot cargo box. Other models are offered in WT, SLE and SLT trim levels, while popular features such as the EZ Lift tailgate and rearview camera system are retained.

Sierra HD professional-grade interiors are refined and well-appointed – and ready to work.

The details: From the available remote starting feature to the unimpeded access offered by the 170-degree-opening rear access doors on extended cab models, the 2011 Sierra HD models reflect the professional grade blend of refinement and functionality for which GMC is known. The interiors have excellent attention to detail and are quieter – thanks to the range of the truck's enhancements. The stronger chassis, quieter Duramax engine and even details like a quieter power steering pump contribute to the Sierra HD delivering exceptional quietness.

Along with quietness, Sierra HD models are designed for work. The interiors feature numerous storage compartments, providing covered access for everything from work gloves to laptops. For those who use their truck as a mobile office, Sierra HDs deliver with available mobile WiFi, USB connectivity, Bluetooth connectivity, XM Satellite Radio and a navigation system. Multiple charge points enable multiple electronic devices to operate simultaneously; and when equipped with the available navigation system, XM NavTraffic offers real-time updates of traffic conditions (in selected areas) that can help plan the most effective route to the job site.

Sierra HDs are ready for the long haul – and the cold.

The details: The 2011 Sierra HDs drive farther without stopping to refuel. A new, 36-gallon (136 L) fuel tank is standard on all models and, with the improved fuel efficiency of the powertrains, enables a cruising range of about 680 miles (1,090 km) with the Duramax 6.6L. Cold-weather customers will appreciate the Duramax 6.6L's quick, reliable start-up, with a starting time on par with gas engines. Its glow plug cycle time is the segment's best in all temperatures, taking no more than 3 seconds in temperatures as low as -20 F (-29 C). There's also a cab heat-up feature that allows the engine to idle faster in low temperatures to warm the interior more quickly.

The 2011 Sierra HD lineup has the best warranty coverage in America.

The details: All 2011 Sierra 2500HD and 3500HD trucks work under the best warranty coverage in America: a five-year/100,000-mile limited powertrain warranty, plus roadside assistance, courtesy transportation and other features that provide assurance that GMC backs its trucks for everything the road offers.

About GMC

GMC is evolving to include more fuel-efficient trucks and crossovers. The GMC Terrain is a smaller SUV that offers 32 mpg highway fuel economy along with the capability, engineering expertise and refinement that have defined GMC for more than a century. Complementing the Terrain are the Acadia eight-passenger crossover, Yukon and Yukon XL and Sierra pickups. Today GMC is the only manufacturer offering three full-size hybrid models. Details on all GMC models are available at www.gmc.com.