There are only minor changes in the GMC Sierra for 2008. This full-size truck is available in different body styles and configurations. For 2008, satellite radio is standard equipment, while an integrated trailer brake controller is optional.

The GMC Sierra 1500 is available in three body styles and five engines. The body styles are: standard cab, extended cab and crew cab. Standard cabs come in either base work or SLE trim, while the extended and crew cabs are available in the SLT trim. Crew cabs have an SL and a Denali trim also. Work trucks are powered by a standard 195-horsepower, 4.3-liter V-6 engine. This can be upgraded to a 295-horsepower, 4.8-liter V-8 or a 315-horsepower, 5.3-liter V-8 engine. Either of the V-8 engines is standard on the SLE trims, while the SLT is equipped with the 5.3-liter engine. The 367-horsepower, 6.0-liter V-8 engine is optional and usually comes as part of the Max Trailering Package. The 403-horsepower, 6.2-liter V-8 engine teamed to a six-speed automatic transmission is exclusive to the Denali trim. A four-speed automatic transmission with a tow/haul mode is standard on other Sierra trucks. Buyers can choose a two-wheel drive, four-wheel drive or, in the case of the Denali, all-wheel drive.

Features including towing packages in the GMC Sierra depend on the model purchased. However, all models have refined interiors, comfortable seats and a striking dash design that is ideal for long drives. The seat cushions can be folded for a nearly flat load floor, while storage space is sufficient.

The long list of safety equipment includes anti-lock brakes with an all-disc setup through the Max Trailering Package or the Denali trim. Adjustable pedals and side-curtain air bags are optional. A stability control system with roll-mitigating technology is standard on crew cabs and optional on extended cabs.