The 2008 GMC Sierra lineup is built on a platform that was introduced last year. It supports the strongest, most capable Sierra lineup in history, with segment-leading fuel economy, capability and power — as well as agile ride and handling and an exceptionally quiet interior.

Sierra 1500 is available in several trim packages, including Work Truck, SL (crew cab only), SLE (SLE1 and SLE2 models) and SLT, along with 2WD and 4WD configurations. Three cab styles — regular, extended and crew cab — and three cargo box lengths — 5 feet 8 inches, 6 feet 6 inches and 8 feet — are offered.

The unique Sierra Denali, a truck that fuses performance and unmatched luxury, also returns for 2008. It is a distinct model, with differentiated, exclusive features that elevate its performance and design, such as an exclusive 6.2L all-aluminum V-8 engine with variable valve timing and a six-speed automatic transmission.

Minor changes

Because the Sierra was all-new in 2007, changes for 2008 are comparatively minor, enhancing Sierra's style and range of models. They include standard XM Satellite Radio on all models, availability of a power-adjustable driver's seat on regular cab models with a bench seat and two new exterior colors: Dark Crimson Metallic and Sonoma Red Metallic. Customers can now order a set of new, 22-inch bright-finish aluminum wheels and complementing tires for their Sierra 1500, available as a dealer-installed option.

Also new for 2008 is an integrated trailer brake controller on light-duty models. It is available on extended cab and crew cab models. Previously available only heavy-duty models, it is integrated with the ABS system and provides immediate and measured brake force signaling to electric-controlled trailer brake systems. There is no requirement for external and/or aftermarket brake control systems. The brake controller switch is conveniently mounted on the lower-left section of the instrument panel.

Later in the 2008 model year, the Sierra All Terrain will bow. This special model is based on the popular Z71 Off Road package and offers a distinctive, eye-catching combination of style and refinement. It is outfitted with special shocks, unique interior and exterior design cues, 18-inch chrome wheels and more.

The 2008 GMC Sierra is designed with a strong and refined appearance befitting the brand's professional grade philosophy, including muscular character lines and rounded edges. The front-end appearance, front fenders, hood and rear fenders are unique. A “center-focused” hood, which flows outward to meet the front fenders and stamped-in rear wheel flares enhance the muscular look.

All models except the fleet-oriented work truck model come with a distinctive chrome hood molding. Sierra's grille is complemented by large, jeweled-appearance headlamps. Sierra SLT models come with a chrome front bumper with a body-color top cap. All door handles feature large, grab-style designs that are easy to open with gloves.

A family of 17- and 20-inch factory-installed wheels and tires is available throughout the Sierra range, with Sierra Denali offering unique wheels. New for 2008 is a set of bright-finish 22-inch wheels, which is available as a dealer-installed option.

Sierra models are more spacious with increased storage space, as well as flush surfaces, tight gaps and tolerances, and improved comfort and convenience. Sierra Work Truck and SLE come with a “pure pickup” interior that features larger controls and door handles that are easier to use with gloves. SLE1 models on regular, extended and crew cabs are equipped with a new 40/20/40-split front bench seat, which features a fold-down armrest and storage compartment.

A large-capacity “double” glove box is integrated into the instrument panel on work truck and SLE models. Cloth seats are standard on SLE models and available on Work Trucks; leather seating is available on SLE models. SLE2-equipped vehicles add a six-way power-adjustable driver seat. Work Truck models are offered in a Dark Titanium interior color; SLE models are offered in an all-Ebony interior color, or Dark Titanium/Light Titanium and Ebony/Light Cashmere combinations.

SLT models feature a luxury-inspired interior with unique instrument panel, door panels, larger-capacity center console and other distinct trim. Heated, 12-way power-adjustable driver's seat, leather seating surfaces, Bose speaker system and heated windshield washer system are standard. Crew cab SLT models add a rear-seat audio system. SLT interior color schemes include all-Ebony, Dark Titanium/Light Titanium and Dark Cashmere/Light Cashmere combinations.

Standard on crew cab models and available on extended cab models is a stadium-style rear seat with a 60/40-split design. It can be easily folded up to provide an uninterrupted load floor. Or, either section of the split seat can be stowed independently, allowing room for both cargo and a rear-seat passenger. Entry to the rear seat/storage area of extended cab models is eased with rear access doors that open 170 degrees.

Convenience items

A variety of useful convenience items are available on SLE and SLT models, including a touch-screen navigation radio, power-operated sunroof, power-sliding rear window and XM Satellite Radio. A rear seat entertainment system is available on crew cab SLE2 and SLT models, and all models are available with a variety of radio systems. XM Satellite Radio is standard on all models.

Responsive driving experience

The 2008 GMC Sierra delivers enhanced stability and driving confidence from a new, boxed frame, coil-over-shock front suspensions and rack-and-pinion steering. Fives suspension systems are available, each tailored to suit specific driving requirements. They include:

  • Z83 — Delivers a solid, smooth ride with monotube front shocks and twin-tube rear shocks.

  • Z85 — Designed for enhanced handling and trailer towing, with monotube front and rear shocks.

  • Z71 — Delivers enhanced off-road capability; features specific monotube front and rear shocks.

  • Z60 — Designed for maximum street performance and offered with 20-inch wheels.

  • NHT — Maximum-capacity trailering.

GM's sophisticated StabiliTrak electronic stability control system helps mitigate the occurrence of rollover events; it is standard on crew cab models and available on extended cab models — and is a segment exclusive. Partnered with an improved, high capacity brake system and four-channel, four-sensor electronic brake controls, the system provides more precise, controlled ABS stops, as well as enhanced traction/yaw stability.

Efficient engines

Sierra models are powered by an efficient lineup of engines, led by the segment's highest-rated V-8 engines. Advanced technology, such as Active Fuel Management (AFM) and variable valve timing (VVT), helps Sierra deliver the segment's best fuel economy. A FlexFuel engine is available — and partnered with fuel-saving AFM — gives customers the choice of powering their truck with E85 ethanol, gasoline or a combination of both fuels. Light-duty engine offerings include:

  • 4.3L V-6 (LU3), rated at 195 hp (145 kW) and 260 lb.-ft. of torque (353 Nm).

  • 4.8L V-8 (LY2), with iron block; rated at 295 hp (220 kW) and 305 lb.-ft. of torque (414 Nm).

  • 5.3L FlexFuel V-8 (LMG), E85-capable with iron block and Active Fuel Management, rated at 315 hp (235 kW) and 338 lb.-ft. of torque (458 Nm).

  • 5.3L FlexFuel V-8 (LC9), E85-capable with aluminum block and Active Fuel Management, rated at 315 hp (235 kW) and 338 lb.-ft. of torque (458 Nm).

  • 5.3L V-8 (LH6), with aluminum block and Active Fuel Management, rated at 315 hp (235 kW) and 338 lb.-ft. of torque (458 Nm).

  • 5.3L V-8 (LY5), with iron block and Active Fuel Management, rated at 315 hp (235 kW) and 338 lb.-ft. of torque (458 Nm).

  • 6.0L V-8 (L76), with aluminum block, variable valve timing and Active Fuel Management, rated at 367 hp (274 kW) and 375 lb.-ft. of torque (508 Nm). This engine is available on SLE and SLT extended and crew cab models as part of the enhanced trailering package.

  • 6.2L V-8 (L92), with aluminum block and variable valve timing, rated at 403 hp (298 kW) and 417 lb.-ft. of torque (565 Nm). This engine is exclusive to Sierra Denali.

The engines are backed by proven Hydra-Matic electronically controlled automatic transmissions, including the 4L60 four-speed automatic, high capacity 4L70 four-speed automatic and a new 6L80 six-speed with the Sierra Denali's 6.2L engine. The six-speed automatic has a wide, 6.04:1 overall ratio — including two overdrive gears — that helps deliver an excellent balance of performance and fuel economy. Also, the 6L80 has a “tap up/tap down” capability that allows the driver to manually select upshifts and downshifts with a button on the column shifter.

As evidenced by its five-star frontal crash test rating from NHTSA, Sierra delivers a perimeter of safety protection through a stronger frame and body structure as well as industry- and segment-leading technology. New features include segment-first StabiliTrak electronic stability control with rollover mitigation technology, head curtain side air bags, which are integrated into strengthened chassis and body structures to provide excellent passenger protection, and segment-first safety belt pretensioners that activate during a rear-end crash.

The head curtain side air bags are available on Sierra SLE and SLT models; they are standard on Sierra Denali models.

Driver control dynamics are enhanced by wider front and rear tracks, as well as more responsive suspensions — including a new coil-over-shock front suspension design and rack-and-pinion steering. Additional safety features are offered on Sierra, including factory-installed remote vehicle starting (segment exclusive), Autotrac active transfer case to help keep the vehicle sure-footed in slippery driving situations, Ultrasonic Rear Parking Assist and a revised, easier-to-use tire pressure monitoring system.