A 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, Suburban, Tahoe SUVs. 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 (pre-2007) models, 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.
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, most with four-speed automatic transmissions moving to six-speed autos, and a 6.2-liter with six-speed automatic. Except for Hybrids and the 6.2-liter, EPA ratings run 13-15 mpg City, 17-20 mpg Highway, and on E85 those numbers drop substantially.
A late addition to the 2009 lineup are XFE (Xtra fuel economy) models with a 5.3-liter V8, six-speed automatic and axle ratio of 3.08:1 that increase EPA ratings form 14/20 to 15/21. Proprietary XFE pieces include aerodynamic upgrades in the form of a soft bed cover and extended front air dam, plus aluminum wheels (including the spare) and lower front suspension arms, locking rear differential, and low rolling resistance tires. A trailering package is standard so XFE models can tow up to 7000 pounds. Next Page