By KBB.com Editors
Even though, for several decades, GMC has represented little more than a rebadged Chevrolet, in 2007 GMC made a concerted effort to distinguish itself from its divisional sibling. With the 2008 GMC Sierra HD trucks, GM's engineers have also made a concerted effort to increase the differentiation between the Heavy Duty pickups and their lighter-duty 1500 counterparts.You'll Like This Car If...
Whether purchasing for commercial construction, agriculture or recreational towing, if your needs are truly "heavy-duty" you'll likely find those needs met with the 2008 GMC Sierra HD, which offers all of the virtues, with few of the vices, normally associated with a "heavy-duty" truck.You May Not Like This Car If...
The Heavy Duty's principal mission is to haul or tow big and heavy things. If you don't need this sort of vehicle and its "heavy-duty" attributes, you'll probably be happier with something not quite so robust.What's Significant About This Car?
XM Satellite Radio is made standard on all models, while dual-rear-wheel versions receive new 17-inch wheels. A power driver's seat is now available on Regular Cab models.Driving It Driving Impressions
Given the number of drivetrain, cab and chassis variations in the GMC lineup, it's difficult to provide one set of observations regarding drivability. However, everything GMC's engineering team did to enhance the driving experience has worked. A more rigid frame, in combination with widened track and retuned suspensions (Z85, standard on 2WD and 4WD models; and Z71, the optional Off-Road suspension), supplies the needed capability without imposing the typical vices of a heavy-duty platform. The ride is composed, handling stable and steering accurate with good on-center feel. With the 6.0-liter gasoline V8, performance might be described as "almost recreational." The Duramax does what diesels do, pulling a lot of load (up to 13,000 lbs.) in an authoritative manner.Favorite Features
This transmission has two overdrive gears to provide relaxed cruising with lower engine speeds and a first gear that's intended to enhance off-the-line response. Of importance to those towing is both Driver Shift Control (tap up and down) and standard Tow/Haul Mode. Though some may wish for an available manual transmission, the six-speed automatic's overall excellence might cure you from wanting to shift your own gears.
Gen-IV 6.0L V8 (Gasoline)
For sheer day-in, day-out driving pleasure the 6.0-liter gasoline V8 is terrific, offering extraordinary response for a vehicle this large.
With the 2008 GMC Sierra there are two available interiors. The base and mid-level Sierra HD standard interior is all about functionality, with an instrument panel focused on ergonomic ease, specific door panels offering larger door pulls and handles, a specific center console and two glove boxes. The "luxury" interior of the SLT trim level offers a driving environment straight out of a top-of-the-line Yukon. With a distinct instrument design, large center console and other specific trim elements the end result is decidedly upscaleExterior
"Upmarket" might be a kiss-of-death descriptive for a heavy-duty pickup, but it will work for the 2008 GMC Sierra HD. The grille is framed by a large chrome or black surround, with the GMC logo as its centerpiece, and is flanked by large headlamps. Corner lights wrap into the flared front fenders, which complement the bulge atop the hood, and there is a sleeker profile by virtue of a 57-degree windshield angle. Functionally, large door handles are "grab-style" (for ease of operation while wearing work gloves), doors extend over the rocker panels and, on Extended Cab models, the rear doors open 170 degrees.Notable Standard Equipment
For truck-oriented capability few things beat power; GMC's standard 6.0-liter Gen IV V8 delivers 353 horsepower and 373 lb.-ft. of torque, and a six-speed automatic transmission meshes perfectly with the engine's capability. Standard safety features include seat-belt pretensioners, tire-pressure monitoring and OnStar.Notable Optional Equipment
For many, selecting the diesel is a no-brainer; GM's Duramax turbo-diesel provides plenty of power and is a lot quieter and smoother than diesels of the past. Those carrying lots of random cargo might better organize it with GM's cargo management system, those living in either excessively cold or warm climates will benefit from remote starting on certain trim levels and those wishing to be entertained will enjoy an enhanced DVD system and CD/MP3 audio. Finally, people who worry about getting lost should opt for the available touch-screen navigation system.Under the Hood
GMC offers two engine choices. Base power is the 6.0-liter gasoline V8 which delivers 353 horsepower and 373 lb.-ft. of torque. Although the EPA doesn't provide a rating for vehicles in this category, past experience suggests GM gasoline engines deliver competitive fuel economy. For those wanting more, the 6.6-liter Duramax provides 365 horsepower and a remarkable 660 lb.-ft. of torque
6.0 liter V8
353 horsepower @ 5400 rpm
373 lb.-ft. of torque @ 4400 rpm
EPA city/highway fuel economy: N/A
6.6 liter V8 Turbo Diesel
365 horsepower @ 3200 rpm
660 lb.-ft. of torque @ 1600 rpm
EPA city/highway fuel economy: N/A
The 2008 GMC Sierra HD has a Manufacturer's Suggested Retail Price (MSRP) starting just over $25,000 for the 2500 Regular Cab in Work Truck trim, while the 3500 WT costs a few hundred more. The diesel option adds another $7,000 to the total and and one could easily spend $50,000 for a heavily-optioned SLT Crew Cab. These numbers are fully competitive with Ford's Super Duty and slightly less than a Dodge Ram. Resale values for all three trucks are expected to be similar.