GM is getting to roll out a lineup of heavy-duty pickup trucks that it believes will give it control of a market long dominated by Ford.
"The superlative power of our new heavy-duty Silverado and Sierra, coupled with their best-in-class capabilities, durability and improved efficiency, nail every customer requirement and then some," says Tom Stephens, a GM vice president of engineering. "They provide customers with nothing less than a new standard for this segment."
Chevrolet Silverado and GMC Sierra each offer 32 heavy-duty models, including 2500HD (3/4-ton) and 3500 Series (one-ton) regular cabs, four-door extended cabs, Crew Cabs and chassis cabs. Four special versions of the heavy-duty pickups, with a reduced gross vehicle weight rating (GVWR), are also available for alternative fuel vehicle customers.
Stephens says the "segment's most powerful gasoline and diesel engines drive the 2500HD/3500 Series to the head of their class in performance. The new powertrains were all validated for an extended operating life of at least 322,000 km, without major component failures. They also incorporate new low maintenance features and provide better economy than the powertrains they replace."
A totally new Duramax 6600 diesel V8 replaces the previously available 6.5-liter turbo-diesel. The Duramax 6600 is a 90-degree, direct-injection, overhead valve, 4-valve-per cylinder, turbocharged and intercooled V8.
"From virtually any perspective," Stephens says, "the optional new Duramax 6600 provides more customer benefits than competing Ford and Dodge diesels."
With 300 hp at 3100 rpm and 520 pound-feet of torque at 1800 rpm, the Duramax 6600 produces 65-70 more horsepower and 20-70 pound-feet more torque than the competition's diesels.
These power numbers deliver what Stephens calls "Segment-leading acceleration at any load level. Acceleration tests actually show that, the heavier the load it pulls, the more quickly the Duramax 6600 outdistances its competitors."
Stephens says this diesel is also "amazingly quiet." At cold-idle startup, for example, it produces only 78 decibels of sound-about half the noise level of its next quietest competitor, Ford's 7.3-liter diesel.
Other plus features of the Duramax diesel would include better fuel economy, easier serviceability, and reduced maintenance schedules.
Stephens is just as bullish on the new and optional Vortec 8100 V8 gas engine, which replaces the Vortec 7400. Built on what he calls "one of the most celebrated engine foundations in automotive history, GM's Big Block V8," the Vortec 8100 has nearly 80 percent new parts. It shares its predecessor's valve and bore centers, and bore diameter, but features a 9.4-mm longer stoke for higher displacement and more power.
More power as in 340 horsepower at 4200 rpm and 455 pound-feet of torque at 3200 rpm, which is 40-65 more horsepower and 30-45 pound-feet of torque than Ford and Dodge's V10s.
Stephens says the Vortec 8100 also provides four percent better specific fuel economy than its predecessor, best-in-class gas engine acceleration and major emissions improvements.
The third engine in GM's new heavy-duty trucks is the new standard engine-the Vortec 6000 V8, which replaces the Vortec 5700 to become the most powerful base engine in its class. With 300 hp at 4400 rpm and 370 pound-feet of torque at 4000 rpm, it produces 40-50 more horsepower and 25-35 more pound-feet of torque than the competition's largest gasoline V8s.
New-for-2001 engine design changes include cast aluminum cylinder heads, intake and exhaust ports that provide major gains in volumetric efficiency (better breathing), a high lift cam, and a low restriction induction and exhaust system. The Vortec 6000 shares the Vortec 8100's low maintenance features.
All new 2500HD/3500 models have a standard engine hour meter that also allows fleet and commercial operators to calculate more precise servicing schedules for their engines.
The Duramax 6600 and Vortec 8100 mate to new smooth shifting, high capacity transmissions, including a standard ZF S6-650 6-speed manual and optional Allison 1000 5-speed automatic. Both have close-ratio gearing, Stephens says, "which provides exceptional launch, hill climbing and towing capability and economy. Their heavy-duty components are stronger than those typically found in one-ton truck transmissions, providing exceptional durability."
Stephens points out that, with their new power, frames, advanced suspensions, and higher capacity brakes, "the 2500HD/3500 Series provide outstanding payload capacities and unparalleled hauling and trailering capabilities, including:
- The 3/4-ton segment's highest 9,200-pound (4,173 kg) GVWR (400 pounds/181 kg more than competitors), and payloads of up to 3,964 pounds (1,798 kgs).
- The one-ton pickup segment's highest 11,400-pound (5,171-kg) GVWR (200pounds/90.7 kg more than Ford and 900 pounds/408 kg more than Dodge), and payloads of up to 5,753 pounds (2,610 kg).
- An 11,400-pound (5,171-kg) GVWR for 2WD chassis cabs and 12,000-pound(5,443-kg) GVWR for 4WD chassis cabs (exceeding Ford's gasoline engine) maximum by 200 pounds/90.7 kg and 800 pounds/363 kg, respectively. Chassis cabs provide payloads of up to 6,089 pounds (2,762 kgs).
Both the Vortec 8100 and Duramax 6600 Diesel V8 permit towing trailers weighing up to 12,000 pounds (5,443 kg); they provide a maximum 22,000-pound (9,979-kg) gross combined weight rating (GCWR). The trucks' best-in-class trailer ratings are only limited by the weight distributing range of the platform hitch itself.
With a fifth wheel or gooseneck hitch (placed about three inches in front of the rear axle), trailering capability increases to 15,800-pound (6,804-kg) maximum. The Vortec 8100 provides its maximum ratings with either a 4.10:1 or 3.73:1 axle ratio; the Duramax 6600 provides them a 3.73 axle ratio.
With a weight-distributing platform hitch and 4.10 axle ratio, the Vortec 6000 V8 permits towing trailers weighting to 10,500 pounds (4,763 kg) and provides a maximum 16,000-pound (7,257-kg) GCWR.
The heavy-duty pickups are completely trailering ready. A Handling and Trailering package is standard. A Trailering Equipment package provides the weight-distributing hitch platform, eight-wire trailer harness with mounted connector and a jumper harness with a convenient plug-in for connecting the electric trailer brake controller.
New features like larger recovery hooks and a wider choice of outsidemirrors than before further enhance towing, Stephens says.