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2007 GM HD Pickups - First Drive

Posted in Vehicle Reviews on June 1, 2007 Comment (0)
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Photographers: Courtesy of General Motors

General Motors needs you to like its new heavy-duty trucks. After all, they are one of the General's most profitable vehicles, and when you add the sales of Chevrolet and GMC together, they outsell the number one-selling Ford Super Duty. No matter how you slice it, the heavy-duty segment of the fullsize truck market still means big profits for struggling automakers, and despite rising fuel prices, they remain important vehicles. GM recently introduced the '07 Silverado and Sierra HD trucks, known internally as the GMT900, and invited us for our first drive of these important new vehicles.

We think the GMC is the better-looking of the two trucks, with its more refined lines.

The first thing you'll notice about the new trucks is the exterior, which matches that of its light-duty siblings, albeit with more muscular proportions. As with the light-duty trucks, we think the GMC Sierra HD is once again the looker of the pair, as the Chevy Silverado HD sports a set of ungainly, chromed jowls, which are about as attractive as Britney between rehabs. The 16- and 17-inch wheel-and-tire looks significantly undersized on these big trucks, and in a market where the competition starts out with 17-inch wheels and goes all the way up to 20s, 16s just don't seem to do it for us anymore. On a positive note, the bodies are extremely tight, and the fit of the panels and tightness of the gaps are among the tops in the automotive industry.

What's Hot: Bold new styling, comfortable interiors, increased fuel economy, best ride of the HD segment.

What's Not: No true F-450 competitor offered, uses upgraded GMT800 chassis, redesign didn't go far enough, offset steering wheel, low ground clearance.

As expected, the new HDs are available in three cab configurations (regular, extended, and crew), two bed lengths (6.5- and 8-foot), in single or dual rear wheels, and in two- or four-wheel drive. With the upgraded 2.5-inch receiver hitch, GM claims the best conventional tow rating of 13,000 pounds and a segment-leading GCWR of 18,500 pounds. With a fifth-wheel hitch, the tow rating improves to 16,700 pounds.

Inside the cabin, you'll find that the same high-quality materials and tight fit and finish found in the GMT900 LD trucks carries through to the HDs. Just as in the LD trucks, we prefer the "pure-pickup" dash to the "luxury-inspired" version shared with the SUVs, as it offers more storage, and gives you places to mount aftermarket accessories, such as radios, gauges, and switches. These interiors, even on the base models, are among the best available. However, we still noticed wind around the A-pillar and windshield header in a couple of our testers, something we have also noted in about half of the LD and SUV GMT900s we have sampled. So if you find wind noise distracting to your driving experience, drive before you buy.

Climbing underneath the big HDs reveals a modified GMT800 chassis that retains torsion bars, rather than switching to the LD GMT900's coilover shocks. GM cites increased durability for the reason to stick with torsion bars on the HDs, but unfortunately it stuck with the low hanging frame as well.

While the low frame height and ground clearance don't inspire spirited wheeling, at least the Z/71 off-road package is available on the HDs for the first time and includes skidplates, different suspension tuning, a high-capacity air cleaner, and a mechanically locking rear differential.

Two engines are offered on the HDs: The iron-block 6.0L Vortec V-8 with variable valve timing and putting out a class-leading 353 hp and 373 lb-ft of torque (for durability, the over 10,000-pound GVWR 3500HD dualie models have power output that is reduced to 312 hp) and the class-leading clean technology turbodiesel Duramax 6.6L V-8. We towed an 8,000-pound trailer with a 2500HD 4x4 equipped with the 6.0L and we think that even big-block die-hards will be impressed, especially with the economy that comes from being backed by an all-new wide ratio 6L90E six-speed automatic.

For those who aren't sold on the 6.0L gas engine, the Duramax is a compelling option, no longer offering the turbo lag or electronic throttle lag of previous models. With 365 hp and 660 lb-ft of torque, the Duramax leads Dodge's new 6.7L Cummins I-6 and Ford's 6.4L Power Stroke V-8, which are both rated at 350 hp and 650 lb-ft of torque. The new Duramax is even certified to run on B5 diesel fuel and is probably the quietest diesel we've ever heard in a heavy-duty pickup. Thanks to a variable-geometry turbocharger, power delivery is smooth and comes on hard and fast, with quick shifts from the new Allison 1000. The Allison, already the beefiest tranny in its class has been upgraded with a sixth cog for 2007, improving fuel economy. Sadly, manual lovers will be forced to bemoan the loss of another manual transmission choice, as the manual transmission bites the dust, leaving the Duramax as a jaw-dropping $8,395 option package-$7,195 for the engine and $1,200 for the mandatory Allison. Diesel buyers can order the Super Duty with a manual for only $6,895, and Ram buyers can do the same for $6,100.

On top is the luxury-inspired interior...

In the details, you can see where the General has spent time studying the competition. We expected innovation, but instead got features that could best be described as derivative. Features such as the roll-down rear extended-cab door windows and tailgate assist may be the first in the heavy-duty segment, but were first seen on the '04 Ford F-150, while the rail system and 170-degree opening rear extended-cab doors are already offered on the Nissan Titan. At least GM buyers have access to these conveniences now, as well as an integrated trailer brake controller a'la Super Duty.

...while the pure pickup is seen here.

Behind the wheel, the HD trucks were a comfortable place to cover long stretches of road with a smooth ride. While the GMT800 trucks were often criticized for having too-soft IFS front ends and too-stiff solid-axle rear ends, the tuning on the new trucks is much improved, no longer having the unladen pogo'ing over freeway expansion joints and uneven roads. We devoured the delicious exhaust note served up by the 6.0L, a song we could have listened to all day. Even the steering is nicely weighted, and the big trucks didn't feel like they needed to be manhandled through twisty mountain roads, handling them with comfort and ease. Braking was also similarly improved.

The main complaint we had while in the driver's chair was an offset steering wheel that is inboard of the centerline of the seat, something that had the tendency to irritate and fatigue the cranky back of one of our testers, a point to keep in mind if you suffer the same ailment.

Overall we enjoyed, but were not smitten by, the new GM trucks. They certainly are an improvement over the outgoing models, but we don't feel that they raised the bar in any particular area and are merely keeping pace with the Joneses. The redesign is exactly what you might expect, with no surprises. What these trucks are is very capable, competent, and well-built pickups that will dutifully fulfill just about any chore that you might have in mind. However, we think GM could have gone farther with this generation, as it has to serve the company in the midst of increasing rivalries for the next seven to nine years. In this hot market, only time will tell if GM might have underestimated the competition with this redesign.

Vehicle model: 2007 Chevrolet/GMC Silverado/Sierra 2500HD Crew Cab
Base Price: $24,575
Engine Type: 6.6L Duramax V-8 (LMM)
Valvetrain: OHV
Aspiration: Turbocharged
Mfg.'s hp @ rpm: 365 @3,200
Mfg.'s torque (lb-ft) @ rpm: 660 @ 1,600
Transmission: Allison 1000 six-speed automatic

Ratios (:1)
First: 3.10,
Second: 1.81,
Third: 1.41,
Fourth: 1.00,
Fifth: 0.71,
Sixth: 0.61,
Rev: 4.49
Axle ratio: 3.73:1
Suspension (f/r): SLA, torsion bar/Semi-elliptical two-stage multileaf spring
Steering: Power assist, recirculating ball
Brakes (f/r): 12.8-inch vented disc/12.8-inch disc
Wheels/Tires: 17-inch cast aluminum/LT265/70R17

Wheelbase (in): 153
Length (in): 240
Width (in): 80
Height (in): 77.1
Track (in): 68.6 (front), 66.0 (rear)
Curb weight (lb): 6718
Ground clearance f/r (in): 9.5
Max Towing capacity (lb): 13,000
Fuel capacity (gal): 34
Seating capacity: 5

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