General Motor's Heavy Duty Pickups Come Work Ready

Sept. 28, 2010

It's like watching a frog race: Full-size pickups, primarily from the domestic Big Three auto makers, leap over each other with new and improved models every few years.

General Motors was the latest to upgrade its vehicles, to where writers at enthusiast magazines have proclaimed the new 1500-series Chevrolet Silverado and GMC Sierra as the best half-ton trucks now available.

But folks who tote lots of tools, supplies and equipment — in the bed or on a trailer — prefer the heavy-duty 3/4- and 1-ton models. For them, GM recently released the 2500HD and 3500HD, which use the 1500's noses and cabs mounted on stronger frames and suspensions.

Does the charm of the highly regarded lighter-duty models migrate upward? Yes and no, I found, after driving several of them during a GM event in Charlotte, N.C.

A rough ride

The HDs look a lot like the handsome half-tonners; and many interior features, including gauges, switches and controls, and trim packages, are shared throughout the line — though there are some style differences in the hoods and noses of Chevy and GMC versions. However, the exceptionally smooth, controlled ride that's one of the Chevy/GMC 1500's finest features is not present in the heavier models.

That was plain after just a few blocks in a couple of 3500HDs I briefly drove, as well as the 2500HD featured here. Over even asphalt, their ride was firm, as one might expect from stronger underpinnings; and over rough concrete, the ride bordered on harsh. This was true with single rear wheels or duals, long or short wheelbases, and simple or posh trim levels.

Simple was the word for the work-truck (W/T) trim on this bright-red Regular Cab pickup. Inside it had a split bench seat with a fold-down armrest and seat bolsters for driver and passenger; the raised upholstery kept my rear and legs in place through corners, but I had to plant my broad beam squarely between the two bolsters to keep my thighs from being pinched. A handsome, tweedy cloth fabric in black-and-grey looked nice, felt good, stayed cool, and will probably wear well.

The dashboard was the "pure-truck" design (a "luxury" style is used on higher trim levels), and the truck had cruise control, air conditioning, and a nice-sounding stereo radio with CD player. But its equipment was otherwise no-nonsense, with rubber floor mats, roll-up windows, and non-motorized mirrors.

The two-piece mirror on the right side was an annoyance, as I had to stretch across the wide cab and roll down the window to grab and adjust the glass, and I couldn't seem to get the convex portion aimed to where I could see enough. Power mirrors are a better idea, especially if a truck will be regularly driven by more than one guy or gal. And as on the 1500s, there is no assist handle for the driver, which made climbing into high-floored 4×4s a chore, as there's only the steering wheel to grab.

Now, would the 2500HD's firm ride settle down while toting a load? GM Fleet & Commercial's press-relations manager, Rob Minton, arranged for one — a pallet of bottled water weighing about 1,300 pounds. A crew fork-lifted it aboard, and as it settled into the bed, the truck's stout, two-stage leaf springs hardly deflected. The ride remained firm but less choppy, and the truck seemed more than able to handle more weight.

This truck had some optional bed hardware that helped secure the load. The pallet's forward edge rested against a tube-and-mesh divider that locks into aluminum rails on either side. Various sizes and shapes of tool boxes are also among the aluminum accessories available as part of this system.

The only gasoline engine offered in HD pickups is the Vortec 6000 V-8, as the big-block Vortec 8100 can now be had only in GM's medium-duty trucks; of course, guys who tow heavy trailers with pickups will choose the Duramax diesel anyway. The 6-liter (364-cubic-inch) Vortec makes up to 353 horsepower and 373 pounds-feet of torque. It does not have Active Fuel Management, which cuts out four cylinders when loads are light to save gasoline and is standard with this engine in 1500-series pickups. Engineers figure that in a heavier truck, the engine will work harder and be less likely to revert to V-4 con-figuration.

The Vortec 6000 in the HD comes only with a new six-speed Hydra-matic (you can't get a manual transmission). The new automatic's 5th and 6th gears have overdrive ratios of 0.85 and 0.67, respectively, and 4th is a slight underdrive at 1.15 to 1. The tranny and its torque converter had a ratio for every situation, so the engine neither lugged nor overreved. It's so smooth that you're not aware of what gear it's in unless you're counting.

Or unless you're playing with the Manual position on the shift quadrant, just below Drive. While in M, you can thumb a sliding switch on the shifter lever to down- or upshift the tranny. I soon learned that leaving it in D and using the Tow-Haul mode worked better. When engaged by a push-button on the end of the shifter, T-H caused the tranny to stay in each gear longer during acceleration and down-shifted all the way to 2nd during braking to add some engine-compression retarding.

Both the Manual and Tow-Haul modes originated several years ago in the six-speed Allison 1000 automatic that comes with the 6.6-liter DuraMax V-8 diesel. While the two Allisons I drove in Charlotte shifted smoothly enough, they thumped roughly into gear from Park or Neutral. I couldn't tell if this is a new characteristic or if these two examples simply needed an adjustment.

Urban sprawl along interstates, state highways, and county roads north and west of Charlotte provided plenty of opportunities to slow, stop and accelerate, giving the Vortec/Hydra-matic powertrain a brisk workout. As temps climbed, I cranked up the windows and switched on the strong A/C. The HVAC controls on this work truck were easily understood rotary knobs, while upscale trim levels use sometimes puzzling push buttons.

New equipment available on the new-series HDs includes a stronger hitch platform with a 2.5-inch receiver (versus the usual 2-inch size) and an integrated trailer-brake controller, which this truck didn't have. Standard is a hydroformed front frame section, larger disc brakes, and revised steering with supposedly better center-line feel, though my hands failed to sense the improvement.

Altogether, I covered about 90 miles in this very able but plain-vanilla pickup, and concluded that GM's new 2500HD and 3500HD are just what they appear to be — good looking, well equipped and built, seemingly easy to live with and, with the proper options, work ready — a combination worthy of your consideration. And if you already own a firm-riding pickup, you'll also feel right at home.

HD pickups use the same nose and cabs as the 1500 series, but are mounted on stronger frames and suspensions. Brakes on the 2500HD are bigger than those on previous models.
A six-liter (364-cubic-inch) Vortec gasoline V-8 has plenty of power and torque; and it works well witha new, smooth-working six-speed Hydra-matic.
W/T (for work truck) trim includes a two- or three-passenger split bench seatwith handsome cloth covering, complete instrumentation in the "pure-truck" style dashboard, and easy-to-use rotary knobs for the HVAC.
Hydra-matic's quadrant includes an "M" position that lets you up- or downshift using a sliding switch on the lever. Here it's in 4th gear at a little over 30 mph.
Optional aluminum hardware in this bed includes a load divider, which the 1,300-pound pallet snugs against, and available tool boxes. HD pickups come with 8- or 6.5-foot beds.
Test Set

Truck: 2007 GMC Sierra 2500HD Regular Cab 2×4 pickup w/8-ft. bed, GVWR 9,200 lb., payload (including people) 3,892 lb., W/T (work-truck) trim

Engine: 6-liter (364-cubic-inch) Vortec gasolineV-8, iron block/aluminum heads, 353 hp @ 5,300 rpm, 377 lbs.-ft. @ 4,300 rpm

Transmission: Hydra-matic 6L90 six-speed double-overdrive w/Manual and Tow-Haul modes

Steering: Integral hydraulic power, recirculating ball

Front axle/suspension: Long- and short-arm independent torsion bar

Rear axle/suspension: Live axle on semi-elliptic 2-stage multi-leaf springs, 3.73 or 4.10 ratio

Wheelbase: 133 inches

Tires & wheels: LT245/75R16 on steel discs

Brakes: 4-wheel hydroboosted hydraulic discs, 12.8- × 1.5-in. front, 12.8- × 1.2-in. rear

Maximum trailer towing: 12,900 lb. w/4.10 ratio

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