The GMC Sierra SLT boasts interior features popularized by the Yukon sport utility, providing a much more upscale environment for the driver and passengers. GMC hasn't forgotten about owners who use their trucks for work, however. So other Sierra models use a pure pickup interior with more function, like dual glove boxes, and less luxury.
The "pure pickup," as it's called, has a unique dashboard that is more driver-oriented and has larger switchgear and door handles that are designed to be easily manipulated by those wearing work gloves. The pure pickup interior includes a 40/20/40 split front bench seat with the center section folding down to provide a large storage compartment and wide armrest.
The SUV-style luxury-oriented interior puts audio and ventilation system controls more easily within reach of the front-seat passenger and has two front bucket seats with a fixed center console with assorted storage compartments.
Either dashboard sports full analog instrumentation, and many have more info available through digital display. Operating controls are GM simple, especially on the pure pickup, while the top-line models central dash has many small white-on-black buttons that may require a short learning curve. Some drivers report peculiar ergonomic details as the steering wheel is slightly offset from the seat centerline.
Rear seating is provided for three people in the extended and crew cab versions, with 34.3 inches of rear legroom in the extended cab and 38.7 in the crew cab, space is similar to Ford's F-150 and Nissan's Titan, and smaller than Dodge's Quad and Mega Cabs and Tundra's Double and CrewMax cabs. The crew cab rear seat is split 60/40 and can folded up individually for a flat load floor; this arrangement is optional on extended cabs.
Access to the rear seating area of the extended cab is eased by rear-hinged doors that open to nearly flush with the bed sides. Sitting in the back seat of the extended cab is made more pleasant thanks to the fact that the windows in the rear access doors power fully down.
We've driven multiple versions of the new GMC Sierra and found all of them to be comfortable.
The 5.3-liter V8 provided plenty of power for the extended cab SLE models we drove and the 6.0-liter V8 was more than enough for the SLT Crew Cab we checked out. All engines need to be revved up (by truck standards) for best grunt. Generally the Sierra models match competitors for smoothness, though by benefit of their five-speed automatics the Ram 4.7 typically runs with GM's 5.3, the Ram 5.7 and Titan 5.6 compete with the GM 6.0, while Tundra's 5.7 and six-speed auto performance can be matched only by the Denali's 6.2 and six-speed auto.
Of the suspensions, the Z83 is claimed the smoothest ride while the Z85 is slightly stiffer and for those who often tow moderate trailers. The Z71 is set up to enhance off-pavement driving. The Z60 configuration is for what GMC calls maximum street performance and includes big 20-inch wheels. The NHT package is designed for Sierra owners who need to tow and carry the heaviest loads.
With NHT, the SLT Crew Cab 4x2 is equipped with the Vortec Max 6.0-liter V8 engine, and a 3.73:1 rear axle. It was fitted with StabiliTrak, side-curtain airbags, a locking rear differential, and a convenience package that includes adjustable pedals, remote vehicle starting system and rear park assist. The SLT with NHT suspension is designed for maximum capacity trailer towing, with a special steering gear, shock absorbers, rear axle and tires.
The suspension is compliant relative to its carrying capacity but if you drive empty and don't tow you don't want to get the NHT package just so you can have the 6-liter V8 due to the harsher ride. Isolation and control are both very good but the best suspension setup for comfort on the widest range of surfaces is typically the Z71 package.
By virtue of its fairly stiff spring and shock rates, the NHT suspension can be driven aggressively on winding roads with tire squeal the primary indication you're approaching limits. Steering is direct by truck standards and nicely weighted, providing good feedback about how hard everything is working though the assist can fall behind during repeated full-lock maneuvering as when backing a trailer.
All new Sierras benefit from much improved brakes over earlier models, whether they have the rear discs or drum brakes.
For 2008, drivers who tow will appreciate the optional integrated brake controller like that used on the Sierra HD. However, be sure your trailer brakes are compatible with it before choosing the option, as some electro-hydraulic disc conversions do not work with the integrated controller.
The highest tow rating is 10,500 pounds on extended cab (not long bed) or crew cab models; top regular cab rating is 8900 pounds. Note these figures typically apply to a truck with just a driver on board, and vary substantially based on a variety of equipment and options.
The standard cab is designed for fleet buyers and others who want a basic truck for work, budget play, or a clean slate for customization. It can be equipped with a standard bed (6-foot, 6-inch) or a long bed (8-foot), two bucket seats or a three-person bench seat, V6 or V8.
The extended cab has two rows of seats with rear-hinged rear access doors that open 170 degrees and have roll-down windows. The extended cab can be equipped with either a short bed (5-foot, 8-inch), standard or long bed. The extended cab can be equipped with seating for five or six.
The crew cab has two rows of seats and four front-hinged doors, like those on a Yukon. The crew cab can be equipped with seating for five or six and comes with the short bed.
Standard equipment on the Work Truck ($17,070) includes vinyl seating surfaces, air conditioning, AM/FM/XM radio, one-year of OnStar, daytime running lights, tire pressure monitoring system, Smooth Ride suspension, 17-inch wheels, chrome bumpers.
The SLE ($24,690) adds a CD player, cruise control, cloth seats, a rear-window defogger, auto-dimming rearview mirror with compass and outside temperatures, leather-wrapped steering wheel, fog lamps, handling/trailering suspension, carpeting and power door locks/windows/mirrors. To this, SLE2 ($28,465) adds premium cloth seats, dual-zone air conditioning, a floor console, six-way power driver and front passenger seats, audio controls on the steering wheel, and machined aluminum wheels.
The SLT ($30,860) adds leather seat trim, a unique instrument panel, six-disc CD changer with Bose sound system, heated windshield washers, front bucket seats with 12-way power adjustment and heat, and polished aluminum wheels; crew cab models also get a rear-seat audio system.
The Denali ($38,095) includes a top-flight interior with leather, heated and powered front seats, unique woodgrain console, side curtain airbags, dual-zone climate control, park assist and so on. Denali options include a heated steering wheel, sunroof, and rear-seat entertainment. Denali comes only as a crew cab with a 403-hp 6.2-liter V8 engine, six-speed automatic transmission and rear or all-wheel drive.
The All Terrain model, available as a late-2008 model, features the Z71 off-road package, heavy-duty trailer package, 18-inch wheels, Rancho shocks, and myriad cosmetic enhancements. When ordered with SLT trim, exclusive two-tone leather is used. All Terrain is available as an extended cab standard box or crew cab, 2WD or 4WD with 5.3-liter or 6-liter engine.
Options for the Seirra include head curtain airbags, a locking rear differential, StabiliTrak, towing and trailering equipment, and a power sunroof.
Safety features include dual front airbags and a tire-pressure monitoring system. Optional head curtain airbags automatically inflate when sensors sense a severe impact to provide extra protection in the event of a rollover or secondary collision. Also available: driver and front-seat passenger side-impact air bags; anti-lock brakes, StabiliTrak electronic stability control with rollover mitigation technology, Autotrac active transfer case, ultrasonic rear park assist, OnStar emergency notification.