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2003 GMC 2500 HD SLT 4WD Crew Cab

Diesel Evolution

GMC ups the ante with its Duramax-powered 2500 HD.

When it comes to heavy-duty light trucks, each of the Big Three has aligned itself with a company that knows a thing or two about diesel engines. Dodge selected Cummins for its inline six-cylinder. Ford developed its 7.3-liter V-8 with International, and General Motors turned to its longtime partner Isuzu in manufacturing its 6.6-liter diesel V-8.

Producing 300 horsepower at 3,000 rpm and 520 pound-feet of torque at 1,800 rpm, the Duramax diesel worked a bit differently from its competition. The engine felt a bit peakier than other diesel engines, a notion reflected in the engine’s specs. For instance, it makes only 5 horsepower less than the HO Cummins in the Dodge, but all 300 ponies don’t make their presence known till the engine is a mere 250 rpm shy of its maximum rpm. On top of that, its torque also comes in later than the Ford and Dodge, at 1,800 rpm.

In fairness, 1,800 rpm doesn’t qualify as a lofty, but it is higher than Ford or Dodge, and it did make a difference in the way the truck drove. It felt like a turbo engine, and it was, but the odd part is that, unlike most diesels, there was a discernible turbo lag at lower rpm. When the boost came in, though, it surged forward with reassuring pressure on the seat of your pants.

That is not to say the GMC is sluggish. In a drag race, the GMC would out-gallop the heavier 7.3-liter-powered Ford Excursion and the Dodge Ram 3500 with the HO Cummins. Granted, the Dodge had a long-throw shifter that made quick gear changes as easy as pole-vaulting, but the GMC still hit 60 mph in less than 10 seconds, some two seconds faster than the Excursion and the Ram. That’s not much, but it made a difference in heavy traffic, especially during daily use.

Unlike the Dodge Ram, the GMC 2500 HD was something you actually could use for daily driving, despite its 12,000-pound towing capacity. It was easy to drive, easy to park and fit through drive-through windows much more easily than any dually ever could.
The GMC also offered a better ride than the dually Ram 3500 we tested in February 2003—and even the Hemi-powered 2500 from April—at the minimal expense of 3,750 pounds of towing capacity. If your trailer doesn’t weigh more than 12,000 pounds, we’d take the GMC over the dually Dodge and the Hemi. The more supple ride is a bonus, considering the superior fuel mileage of the Duramax, compared with the Hemi and the Cummins.

 We netted better than 15 miles per gallon without a boat and just less than 15 with a boat. That’s good, considering it had a fairly small fuel tank—for the breed—at 26 gallons. With a boat in tow, the 2500 HD’s cruising range was in the neighborhood of 350 miles.
Some routes take you over some pretty significant hills, and we can’t say how much fuel mileage would suffer as a result. We can say that the GMC 2500 HD required a lot of pedal—read floored—to travel uphill with an 8,000 pound trailer in tow.

Heading downhill, the 2500 HD’s brakes required only a light pedal effort, yet provided plenty of power for slowing down the combined 13,000-plus pounds. The pedal had a little play at the top, but brake feel was good, like a much smaller truck. Considering that the system was boosted hydraulically, we’d have to congratulate the engineers on their achievements.

The antilock system, however, could use some refinement. During fire-and-brimstone panic stops, the system engaged at the proper threshold, but shook the truck more than we’re accustomed to. It also seemed to lock the individual wheels longer before releasing, even on dry pavement. The Southwest is normally is as dry as a glass of oaky chardonnay, but the rest of the country gets rain and snow a lot, and it seemed to us the 2500 HD’s system might not be as effective in wet weather.

We did engage the four-wheel drive system, which couldn’t have been simpler. Put it in neutral and rotate a knob. The servo-driven transfer case took care of meshing the gears. The driveline felt tight and provided ample power to spin front and rear wheels, leaving clouds of dust behind us.

Outside rear-view mirrors—interestingly enough, shaped like Nebraska—included in the SLT package were fine for towing, so good that you don’t really need the optional extended mirrors.

We also liked the newly redesigned interior. With four real doors and big, comfortable leather seats, long trips were a snap. Another creature comfort we enjoyed was the center console, with a rubber-matted tray in the lid, so your cell phone didn’t slide around when negotiating curves and corners. Inside, the console had a power outlet at the rear and a built-in CD rack. In this case, it also could be used for DVDs because the 2500 HD SLT came with a 7-inch screen that flipped down from the ceiling for rear-seat passengers.
As if that weren’t enough, GMC provided two wireless infrared headsets for rear passengers with independent volume control, a wireless remote control and auxiliary video, and audio jacks.

That ought to keep the kids busy—and quiet—on those long trips to the racetrack, the ocean or wherever you go. From its comfortable interior to its miserly diesel engine, GMC showed that it knows a thing or two about building trucks.


Fuel Consumption:
Towing...     14.5 mpg
Non-towing... 15.3 mpg

0-60 towing... 25.12 seconds
40-60 towing... 10.94 seconds
0-60 non-towing… 9 seconds
40-60 non-towing... 5.94 seconds

Engine... 6.6-liter Duramax diesel V-8
Horsepower...  300    @   3,000  rpm
Torque...   520 pound-feet @   1,800  rpm
Compression ratio... 17.5:1
Transmission... Allison five-speed automatic

Axle ratio... 3.73:1
Fuel capacity... 26 gal.
Tire size... LT245-75-R16
Brakes... Hydraulically boosted, four-wheel disc with four-wheel ABS
Suspension... Front: long- and short-arm independent torsion bar; Rear: semi-elliptic two-stage multileaf spring.
Tow rating... 12,000 lbs.
Gross Vehicle Weight Rating... 9,200 lbs.
Gross Combined Weight Rating... 17,200 lb.

Overall length... 227.7"
Maximum width... 79.7"
Wheelbase... 153"
Curb weight... 5,631 lb.
Base price...$34,889
Price as tested... $46,784

Formula 271 FAS3Tech
8,000  lbs.

Customer service...800-462-8782


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