Added standard features and introduction of a light-duty Crew Cab highlight 2004 for GMC's version of GM's full-size pickups. Sierra shares its design with the Chevrolet Silverado. This report covers the half-ton 1500-series models. They offer regular-, extended-, and crew-cab body styles. Extendeds have rear-hinged back doors that don't open independently of the fronts. Crew cabs have four conventional doors. Both include a 3-person rear bench seat. Extendeds and crew cabs offer front bucket seats vs. a bench. Regulars and extendeds are available with conventional 6.6- and 8.0-ft Fleetside cargo beds or a 6.6-ft flare-fender Sportside box.

The new half-ton Crew Cab has a shorter bed than the previous 1500 Heavy Duty Crew Cab, which for '04 is redesignated as a 2500-series model. The new 1500 Crew Cab uses a new 5.8-ft cargo box and is virtually the same length overall as the extended-cab short-bed model.

Sierra comes in Work, base, SLE, and SLT trim. The flagship Sierra Denali is a luxury/performance extended cab with all-wheel drive. Other Sierras come with rear-wheel drive with optional traction control or with one of two 4WD systems. The base 4WD setup must be disengaged on dry pavement. Optional Autotrac 4WD can be left engaged on dry pavement. Unlike Denali's AWD, the 4WD systems include low-range gearing. GM's Quadrasteer 4-wheel steering is standard on Denali and available on other Sierra extendeds. It provides a tighter turning radius at low speed and is designed to aid stability at high speed or when towing. A special flare-fender short box is included with Quadrasteer. Antilock 4-wheel disc brakes are standard. Available is a ride-control suspension with two levels of shock-absorber firmness to suit road or load.

Regular and extended Sierras have a 4.3-liter V6 and offer 4.8- and 5.3-liter V8s. The new light-duty Crew Cab will use the 5.3 V8. Denali has a 6.0-liter V8. Crews and extendeds include automatic transmission with GM's Tow/Haul mode. Regulars offer manual transmission or optional automatic.

For 2004, base models gain standard chrome exterior trim and cruise control, SLEs now come with fog lamps, and extendeds offer optional rear under-seat storage. Satellite radio is optional on SLE, SLT, and Denali, and rear DVD entertainment is optional for Crew Cabs. Sierra's performance and accommodations mirror those of similarly equipped Silverados.