The front-end design of the 2008
GMC Sierra emphasizes the truck's wide stance. The GMC emblem is set amid dark horizontal bars in the middle of an upright and chrome-surrounded grille. The headlamps are a pair of stacked, jeweled lenses. The front bumper features round fog lamps and a wide air intake and wraps around the sides of the truck to the front lower edge of the front wheel wells.
The Denali gets its own chromed grilles, both the upper section and the air vent below the front bumper, and the bumpers are painted to match.
The hood has a pair of long, narrow V-shaped power bulges and leads back to a steeply raked windshield. The windshield is tilted back for improved aerodynamics and enhanced highway fuel economy.
The side view features slightly bulging and elongated fender flares that sweep down behind the headlamps. The sides of the cargo bed are higher than on previous models, and the exterior of the tailgate is sculpted, enhancing the rear view of the truck. Stacked tail lamps are on either side of the tailgate.
Two new reds are available on a truck that looks taller and stronger than its predecessor, yet also has improved aerodynamics. Engine choices include a V6, a 4.8-liter V8, four 5.3-liter V8s (iron and aluminum blocks, some E85 flex-fuel capable, all with Active Fuel Management that disables some cylinders for fuel economy), a 6-liter V8, all with four-speed automatic transmissions, and on the Denali only a 6.2-liter and six-speed auto. Except for Denali, EPA ratings run 13-15 city, 17-20 highway, and on E85 those numbers drop substantially.
An optional cargo management system is available for the bed with side rails and various cargo-carrying and cargo-controlling boxes and dividers and tie-downs.
The GMC Sierra and Chevy Silverado are built on the GMT900 platform that debuted in 2007 and shares many underpinnings with the Yukon SUV. The pickups get a unique rear suspension and frame section that is 245 percent stiffer. The Sierra and Silverado share mechanical components, with the exception of the unique features found on the Sierra Denali.
Compared with the previous-generation, the current frame is 234 percent stiffer in torsional rigidity, 62 percent more resistant to bending and 136 percent stiffer laterally. This yields a smoother ride and better handling. It also allowed the engineers to reduce the gap between the truck bed and passenger compartment as well as the gaps between fenders and bumpers, all of which enhances aerodynamics and fuel efficiency.
The front suspension uses a coil-over-shock setup and the rack-and-pinion steering gear is mounted to the engine cross member frame. The truck also has a new rear axle design with shocks absorbers mounted outboard and more upright for better dynamic control. next page