GM’s 3/4 ton (2500) and 1 ton (3500) Chevrolet Silverado and GMC Sierra HD pickups are all-new for 2001. Based on the standard full-size GM pickup introduced for 1999, the HD models have a stronger frame, slightly different styling, a higher ride height, higher payload and towing capacities, and more powerful engine choices, including an all-new 300 horsepower 6.6 litre Duramax turbo-diesel engine and 5-speed Allison automatic transmission.
New Duramax diesel engine provides class-leading performance
In late November, GM invited a group of Canadian journalists to Calgary, Alberta to get some driving time in the all-new, Chevrolet Silverado and GMC Sierra Heavy-Duty 2500 (3/4 ton) and 3500 (1 ton) pickups. I spent two days in the Calgary/Kananaskis area driving these trucks, a good opportunity to compare the different engines, transmissions, and bodystyles under varying road conditions – from snow-covered mountain passes to bare, prairie highways.
GMC Sierra HD 2500 and Chevy Silverado HD 3500
As GM’s heavy-duty trucks are frequently used for towing trailers and hauling loads, part of my drive included towing a 5000 lb. horse trailer.
GM’s new 2500HD and 3500HD full-size pickup trucks are based on the 1/2 ton and 3/4 ton pickups which were redesigned in 1998 for the 1999 model year. The 2001 HD pickups have a stronger frame, a different choice of engines with more power and increased hauling and towing capacities, and a number of other special features related to towing and work needs.
The styling of the heavy-duty trucks is similar to the standard GM pickups, but the HD trucks are 51 mm (2 in.) taller with a higher hoodline, wider fender flares, and a different grille with a wider chrome bar and a different headlight arrangement. Dual rear wheels with a rust-free composite ‘dually’ fender design are standard on 3500HD models and optional on 2500HD trucks.
Two new engines
While 1/2 ton and 3/4 ton Silverado/Sierra pickups come with a choice of 4.3 litre V6, 4.8 litre V8, and 5.3 litre V8 engines, the new 3/4 ton HD and 1 ton HD trucks offer a standard 6.0 litre V8 engine, an all-new 8.1 litre V8, and an all-new Isuzu-built Duramax 6.6 litre V8 turbo-diesel engine. The latter two engines are now the most powerful engines in the over 8500 lbs GVW pickup class.
The new Duramax 6.6 litre V8 turbo-diesel replaces GM’s 6.5 litre turbo-diesel engine. The Duramax engine was developed in conjunction with Isuzu which, I discovered, is one of the world’s largest diesel engine manufacturers. Duramax engines are built by GM in Moraine, Ohio.
GM claims the Duramax is the most powerful diesel engine ever developed for a pickup truck. It’s rated at 300 horsepower at 3100 rpm and 520 ft-lb of torque at just 1800 rpm. This compares to Ford’s 7.3 litre Powerstroke V8 turbo-diesel with 275 horsepower and 520 ft-lb torque, and Dodge’s Cummins turbo-diesel which has 245 horsepower and 505 ft-lb. of torque.
The 90 degree, OHV, four valve per cylinder Duramax 6.6 litre turbo-diesel V8 engine features Bosch Direct Injection Common Rail Fuel system, a water-cooled turbocharger, an integral oil cooler, transmission oil cooler, piston spray cooling, and charge air cooler. GM says the Duramax engine will last at least 320,000 km with proper maintenance.
Fuel consumption figures were not available, but GM says the 6.6 litre Duramax offers an improvement of 15 to 20% over the previous 6.5 litre V8 turbo-diesel.
Diesel engines are often noisy, but GM says the Duramax is the quietest in its class, producing 78 decibels of sound at cold idle startup – GM claims this is half the sound level of the Ford 7.3 litre turbo-diesel – more on this in a minute.
GM’s other new engine is the 8.1 litre V8 which replaces the previous 7.4 litre V8 engine. The 8.1 litre V8 develops 340 horsepower at 4200 rpm and 455 ft-lb. of torque at 3200 rpm – more than it competitor’s V10 engines. Ford’s 6.8 litre V10 has 310 horsepower and 425 ft-lb. of torque, and Dodge’s 8.0 litre V10 offers 310 horsepower and 450 ft-lb. of torque.
Even GM’s standard 6.0 litre V8 engine, which replaces the 5.7 litre V8, has 300 horsepower at 4400 rpm and 360 ft-lb. of torque at 4000 rpm – or about 40 to 50 more horsepower and 25 to 35 more ft-lb of torque than competitors comparable powerplants.
Two new transmissions
GM needed a heavy-duty transmission to handle the 520 ft-lb. of torque of the Duramax diesel engine, so they engaged Allison Transmissions, a leader in the medium-duty automatic transmission market, to supply one.
The heavy-duty Allison 1000 5-speed automatic transmission features engine grade braking – it shifts down automatically from fifth to fourth gear when going downhill to improve braking and vehicle control, and to avoid overheating the brakes (particularly with a trailer in tow). It’s capable of handling a GVWR of up to 19,850 lbs or a GCWR of up to 26,000 lbs. It also offers a Power Take-Off bolt-on feature which allows running external devices like pumps or generators.
A new ZF 6-speed manual transmission is also available which offers a high torque and load capacity, improved shift feel, long-term durability, and a power take-off provision. The 6.0 litre V8 engine is available with a carryover 5-speed manual transmission or optional Hydra-Matic four-speed automatic transmission which now features adaptive shift control, smoother shifts, and so-called ‘Abuse and Shift torque management’.
All GM automatic transmissions feature Tow/Haul mode, a driver-selectable shift mode which uses a different computer shifting program to account for the extra weight of a trailer or load, and the grade of the road. In Tow/Haul mode, the torque converter engages in second, third, fourth and fifth gears to avoid excessive transmission heat build-up. It also reduces ‘shift busyness’ in hilly terrain. With the five-speed Allison transmission, the Tow/Haul mode will automatically shift down from fifth to fourth to third to slow the truck on steep grades.
Stronger frame, and class-leading towing capability
To handle increased payloads and towing capacities, GM’s 2500 and 3500 HD trucks have a stronger frame than the standard 1/2 ton and 3/4 ton pickups. The chassis cab rails are over 12 inches deep and 1/2 inch thick in high stress areas, and GM claims a best-in-class GVW rating of 9,200 lb for 2500HD models, and 11,400 lb. for 3500 HD trucks.
For both 2500HD and 3500HD trucks equipped with the 8.1 litre V8 or 6.6 litre V8 turbo-diesel engines, GM claims a best-in-class trailer towing capacity of 12,000 lbs (about 2000 lb. more than its competitors) and a best-in-class fifth-wheel towing capacity of up to 15,900 lbs, a 2,900 lb. increase over the previous model. The GCWR is 22,000 lbs.!
The GM 2500HD truck will haul payloads up to 1790 kg (3947 lb.) and the 3500HD truck will handle payloads of up to 2583 kg (5696 lb.)
New features for 2001
All of GM’s new full-size pickups have a new independent front suspension which includes torsion bars on both 4X2 and 4X4 models. It provides a better ride, improved steering feel, and better stability. 4X2 models have a considerably wider track than previous models (up to 135 mm/5.3 in.).
At the rear, the Heavy-Duty pickups have standard multi-leaf springs and solid rear axle. All models have a wider rear track of up to 43 mm/1.7 in.) for improved stability.
For the first time, four wheel disc brakes are being used on GM HD pickups. These brakes feature larger front rotors and a 35% increase in pad size. In addition to shorter stopping distances (48.6 m/160 ft. from 100 km/h to 0 unloaded), the new brakes have a more solid pedal feel and require less pedal effort.
4X4 models are available with both manual and electric shift transfer cases which can be engaged without leaving the cab. New for 2001 on Heavy Duty pickups is an electric transfer case with an automatic transmission – with a push-button, the driver can select 2HI (two-wheel-drive), 4HI (part-time 4WD), 4LO (low range gear), or Neutral (for flat towing behind a recreational vehicle).
Other improvements to GM’s heavy-duty trucks include wider 16 X 6.5 inch wheels, higher E-load range tires, and improved steering feel, and larger 6.5 cu. ft and 8.0 cu. ft. boxes with 2 percent more cargo volume.
Crew cab is roomy
Like the standard GM pickups, the HD regular cab and extended cab models have considerably more interior room. For 2001, all extended cab models have two rear-hinged doors instead of one.
My test vehicle was a four-door, Crew-Cab bodystyle which has a larger cabin than the extended cab model, and easier access for rear passengers. A three-passenger 40/20/40 split front bench seat is standard, but two individual bucket seats are also available. With the bucket seats comes a lockable centre storage/armrest with two cupholders – it also has two rear cupholders and air vents for rear passengers.
The 60/40 split rear bench seat can be folded down to create more interior storage space, and if two passengers are seated in the rear, there’s a centre armrest with two cupholders and storage bin.
I found the Crew Cab’s wide front bucket seats very comfortable on a long drive, and outward visibility, enhanced by the truck’s high ride height, is excellent. Step-in height is high, however.
As well as a speedometer and tachometer, the Silverado’s instrument panel includes an engine hour meter, and a transmission oil temperature gauge.
I spent much of my driving time in a Silverado 2500 HD Crew Cab long box 4X4 equipped with the optional Duramax engine and Allison 5-speed automatic transmission. When starting this motor on a cold sub-zero morning, it was initially noisier than a nearby Ford 7.3 litre turbo-diesel and a Dodge Ram Cummins turbo-diesel. But after a few seconds, it settled down to a low ‘rattle’, confirming GM’s claim that it is quieter than the competition. Still, I wouldn’t say it is half as loud as Ford’s diesel engine, as GM claims.
With maximum torque of 520 ft-lb. developed at just 1800 rpm, the Duramax-equipped Crew Cab had no trouble pulling our 5000 lb. trailer up long, mountain roads at elevations up to 6000 feet. To prove the Duramax engine outperforms its competition, General Motors set up a 1/4 mile drag race between a Duramax Silverado extended cab hitched to a 5000 lb. trailer, and its two Ford and Dodge diesel competitors with equal weight trailers. Predictably, the GM truck won every drag race, but it was the margin that was surprising: out of the gate, the Duramax was only slightly faster, but it rapidly pulled away from the others beating them by at least a truck and trailer length at the end of the 1/4 mile.
I was thoroughly impressed with the Allison 5-speed automatic transmission – this transmission is the cat’s meow if you want to tow a heavy recreational or work trailer over long distances. It shifts quickly, confidently, in a timely fashion, and seems to anticipate grade changes and curves by shifting at or before they arrive! With Tow/Haul mode engaged, the Allison transmission shifts down rapidly and automatically from fifth to fourth to third, minimizing brake use, and preventing the rapidly escalating momentum that can occur when towing a heavy trailer downhill. When going down a grade, the driver can induce the transmission to change down a gear by stepping on the brake pedal, but even if he/she doesn’t, the transmission will take care of it.
On the highway, the Duramax turns over just 1800 rpm at 100 km/h, right where its maximum torque lies. When accelerating, shifts take place at about 2500 rpm, then settles back to 2300 rpm when the torque converter engages. The redline on this diesel engine is only 3200 rpm.
In my opinion, the combination of the torque-rich Duramax diesel and the eerily-intelligent Allison 5-speed automatic transmission is probably the best engine/transmission combination currently available in a pickup today. They are expensive options though. The Duramax engine is a $5695 option, and the Allison transmission is a $2395 option when you upgrade from a manual transmission, and $1160 when you upgrade from a four-speed automatic transmission.
I also drove an extended cab Silverado 3500HD with the 8.1 litre V8 engine and the Allison transmission. This gas engine is considerably quieter than the Duramax diesel, but doesn’t have quite as much low-end grunt when towing – maximum torque is 455 ft-lb. at 3200 rpm – and it uses more fuel. Still, if I wasn’t towing a really heavy trailer, and I could afford the gas, I’d rather have the 8.1 litre V8 because it’s quieter and smoother. For work around the farm, or on the job-site, or for big towing jobs, the Duramax engine is probably the better choice.
On the highway, I found the 3500HD (1 ton) models had a stiffer ride than the 2500HD (3/4 ton) trucks. Still, when unloaded both had a surprisingly comfortable ride with less chop that I expected. With a load in the box or a trailer in tow, the ride improved in both models, but was better in the 2500HD models.
The Crew Cab trucks, particularly with the long box, are very long. A 90 degree turn requires pulling out wide enough so that the inside rear wheel doesn’t catch the curb as you round the corner. 180 degree U-turns also have be be made with some forethought.
Still, I found these big trucks very easy to drive – they’re stable at highway speeds, easy to steer, have excellent brakes, and good outward visibility. Offered in base, LS, and LT trim levels, they’re available with all the creature comforts you’ll find in a luxury vehicle, such as leather upholstery, automatic climate control and premium stereos.
GM 2500HD and 3500HD pickups range in price from $26,910 to $45,315 plus optional engines and transmissions. You’ll be looking at over $50,000 for a top-of-the-line model.
For heavy-duty recreational and work-related towing needs, GM’s new HD pickups now offer serious competition for Dodge and Ford trucks. In areas like interior room, engine noise, acceleration, and maximum towing capacity, GM’s trucks are clearly superior.
|2001 Chevrolet Silverado 2500 HD Crew Cab 4X4 long box dually|
|Price as tested||$52,000|
|Type||4-door, 6-passenger full-size pickup|
|Layout||longitudinal front engine/4WD|
|Engine||6.6 litre V8 diesel, turbocharged|
|Horsepower||300 @ 3100 rpm|
|Torque||520 ft-lb. @ 1800 rpm|
|Transmission||5-speed automatic (std. 6 speed manual)|
|Max. trailer capacity||5443 kg (12,000 lb.)|
|Max. 5th wheel||7212 kg (15,800 lb.)|
|Max. payload||1790 kg (3,947 lb.)|
|Max. GVWR||4173 kg (9,200 lb.)|
|Wheelbase||4242 mm (167.0 in.)|
|Length||6507 mm (256.2 in.)|
|Width||2438 mm (96.0 in.)|
|Height||1877 mm (73.9 in.)|
|Warranty||3 yrs/60,000 km|