GMC updated its complete line of full-size Sierra pickup trucks for the 2003 model year and incorporated a new electrical architecture. While this General Motors division positions its trucks as "professional grade," the similar Chevrolet Silverado ranks as the high-volume member of the duo.
Sierras are available in half-ton 1500, three-quarter-ton 2500HD and one-ton 3500 forms. No regular 2500 series exists, but a 1500HD is offered. Whereas the higher-rated models provide an increased level of hauling and towing capabilities, the 1500 series offers editions that aren't available in the others, like the Sierra Denali luxury pickup.
For 2006, GMC's Sierra Hybrid expands to nationwide availability; it previously was offered only in select markets. Though its electrical motor does not actually propel the vehicle, GMC still classifies it as a hybrid.
(Skip to details on the: Sierra Hybrid | 2500HD | 3500)
The Sierra Denali is a luxury pickup with a 345-horsepower, 6.0-liter V-8; permanent all-wheel drive; and a specially tuned suspension. Chevrolet doesn't offer an equivalent to the Sierra Denali, and GMC offers no equivalent to the high-performance Chevrolet Silverado SS. Offered as a Crew Cab rather than an extended-cab truck, the Denali features leather seats and can be fitted with a sunroof and 20-inch wheels.
For 2006, several new packages, trims and configurations are available — most notably a new base-model 1500 SL Crew Cab at a lower price than the 2005 base SLE Crew Cab. Also, the optional 6.6-liter turbo-diesel V-8 on Sierra 2500HD and 3500 models gets more power, and a new six-speed-automatic transmission replaces the previous five-speed in models equipped with this engine.
Light-duty Sierra styling is similar to the heavy-duty models. The Terra4 concept truck inspired the Sierra 1500's front end. Sierras differ from Silverados mainly in the front, which is dominated by a bolder grille and a prominent red GMC badge.
Regular-cab, extended-cab and Crew Cab models are offered. Crew Cab trucks have four conventional front-hinged doors. Extended-cab trucks have two front doors and a pair of narrow back doors that open toward the rear and can't be opened unless the front doors are open. The 1500HD is available only in Crew Cab form. Denalis have chrome running boards and a unique front fascia.
Regular-cab models seat either three occupants on a bench or two in twin buckets, while extended-cab pickups have a rear bench seat and can carry five or six people. Models with bucket seats have a standard center console that flows up into the instrument panel. Optional uplevel mirrors have a power-folding feature for parking in narrow spaces. For 2006, available camper mirrors offer manually extendable surfaces for increased visibility when towing a camper or trailer.
XM Satellite Radio is available. Denali and SLT models have a six-CD changer. Crew Cab trucks can be equipped with a DVD-based entertainment system.
Under the Hood
The engine choices for the Sierra 1500 include one V-6 and a selection of V-8s. A 195-hp, 4.3-liter V-6; a 285-hp, 4.8-liter V-8; and a 295-hp, 5.3-liter V-8 are offered. A version of the 5.3-liter V-8 can run on gasoline or E85, which is 85 percent ethanol and 15 percent gasoline. An aluminum variant of the 5.3-liter V-8 produces 310 hp. The Denali is fitted with a 345-hp, 6.0-liter V-8, while the 1500HD is powered by a 300-hp, 6.0-liter V-8. Available transmissions include a five-speed manual and a four-speed automatic.
Three four-wheel-drive systems are available. Insta-Trac is an on-demand system with a floor-mounted transfer case; it is available on base models. Autotrac is an automatically engaging system that transfers power to the front wheels, as needed, on slippery surfaces; this system can be installed on SLE and SLT trim levels. The Sierra Denali is equipped with full-time all-wheel drive.
Daytime running lights and antilock brakes are standard. GM's OnStar communication system is available on some models.
Like the Silverado, GMC's Sierra 1500 can be equipped with simple features for basic work duty or it can be fully decked out with extras to make it resemble a luxury vehicle. High-end models are quite appealing for regular driving. Though the Sierra certainly isn't carlike, drivers may occasionally forget they're inside a truck.
The Sierra 1500 exhibits above-average quietness. Even though the ride isn't cushiony, a luxury edition is about as smooth on pavement as you're likely to find in a pickup. The 5.3-liter V-8 delivers plenty of zip, and it's matched to a well-behaved and quick-responding automatic transmission.
Because of their manageable size, these pickups are relatively easy to judge while parking, and climbing aboard a four-wheel-drive model isn't an arduous task.�
Late in the 2004 model year, GMC launched a Sierra Hybrid pickup. At the same time, Chevrolet introduced a closely related Silverado Hybrid. Offered initially to fleet buyers, each became available to retail customers in select states in 2005. The Sierra Hybrid will be available nationwide for 2006.
GM claims the Sierra Hybrid achieves up to a 10-percent fuel-economy improvement due to the workings of the compact 14-kilowatt starter-generator. This starter-generator permits the Sierra Hybrid to automatically stop and restart its gasoline engine at stoplights or for other temporary halts. It also provides regenerative braking while the truck is coasting. Unlike other hybrid models on the market, the electric motor doesn't actually propel the vehicle.
The 5.3-liter V-8 has the same output ratings as the conventional version: 295 hp and 335 pounds-feet of torque. Whenever the engine shuts itself off, which occurs as promised, it's difficult to discern that anything unusual has happened. The system also serves as a mobile power-generating station. There are 120-volt power outlets located under the rear seat and in the pickup bed.
According to estimates by the Environmental Protection Agency, these pickups can achieve 17 - 18 mpg in the city and 19 - 21 mpg for highway driving, which amounts to a 2 mpg improvement in city driving and a 0 to 1 mpg gain on the highway when compared with equivalent models. Back to top�
Sierra 2500HD trucks come in Work Truck, base, SLE and upscale SLT trim levels. A rear-seat DVD entertainment system with a 7-inch screen and wireless headphones is available for Crew Cab models.
Extended cabs have two front doors and a pair of narrow back doors that open toward the rear, but they can't be opened unless the front doors are open. Crew Cab models have four conventional doors that open toward the front, and they can seat up to six occupants when properly equipped. Regular-cab models are also available.
The standard 6.0-liter V-8 produces 300 hp and 360 pounds-feet of torque, while an available big-block 8.1-liter V-8 churns out 330 hp and 450 pounds-feet of torque. Both engines can team with either a manual or automatic transmission. The optional 6.6-liter Duramax turbo-diesel V-8 has been extensively revised for 2006 and now generates 360 hp and 650 pounds-feet of torque when mated with a new six-speed-automatic transmission. Insta-Trac part-time four-wheel drive features a floor-mounted transfer case. Back to top�
GMC's heavy-duty one-ton 3500 series comes in Work Truck, base, SLE and upscale SLT trim levels, with a choice of three cab styles. Some Sierra 3500 trucks have two pairs of rear wheels.
Sierra 3500 pickups have a standard 6.0-liter V-8 that produces 300 hp and 360 pounds-feet of torque, while GMC's big-block 8.1-liter V-8 makes 330 hp and 450 pounds-feet of torque. Both engines will be available with either a manual or automatic transmission. An extensively revised 6.6-liter Duramax turbo-diesel V-8 will be available in mid-2006. It generates 360 hp and 650 pounds-feet of torque when mated with a new six-speed-automatic transmission. Back to top