2011 Chevrolet 2500HD/3500 TrucksBy Jim Bigley Copyright 2010 by www.TheDieselPage.com
The past few months have been interesting, with regard to learning more about what direction the GM HD pickups are going. The national economic climate and GM's restructuring have certainly raised a few questions. Since we're focused on the GM diesel, I learned some months ago that DMAX, the company that produces the Duramax 6600, suspended manufacturing this past December and that production won't begin again till April 2010. This lapse in production was certainly curious, and produced a litany of rumors. The log jam of information finally broke this past February 4th, and we learned all about GM's plans for the 2011 model year GM 2500HD/3500 series pickups. Though we're expecting a price increase of $3,000-$5,000, due to the addition of the "Diesel Exhaust Fluid" (urea) system, GM is back with a range of improvements and upgrades that promise to make GM the HD diesel truck leader.
While the sheet metal incorporated into the 2011 model-year trucks is largely the same as that introduced in 2007, nearly everything else, from the chassis, drivetrain to the interiors are all new or significantly upgraded for 2011. I participated in a live GM-produced webcast this past February 4th, which provided an early look at the new trucks and all of the new features and capabilities. What I learned is that it's actually a great time to be a Duramax enthusiast!
The front bumper has been tweaked to better help it blend into the front clip and to reduce the large expanse of chrome seen on previous models, and the hood has been tweaked to provide a more aggressive look. In addition, a new set of optional 20" wheels are now available for the 2500-series trucks. Enthusiasts have known GM needed larger wheels for quite a while - witness the popularity of aftermarket wheels. The optional wheels help provide a degree of confidence in knowing that they will have the designed payload and offset that meet both the safety and drivability requirements new truck owners expect.
During the live webcast, Jim Mikulec, GM's HD lead development engineer, held up a pair of front swaybar links to show how many chassis components were carried over from the 2010 models. From the sheet metal down, nearly everything is all new - including a completely new chassis. The fully boxed steel frame provides a stiffer platform, offering a 5-fold increase in torsional strength and a 20% increase in beaming strength. The new independent front suspension utilizes larger and stronger components, which allow for a 25% increase in the front axle weight rating - making all of the 4WD models snow plow capable. We all know that GM has provided an industry-leading ride quality and that torsion bar trim can be adjusted when adding accessories to the front of the truck (like a snow plow). Can't do that with a spring-over-coil or leaf spring front suspension.
The new chassis allows for somewhat longer wheelbases - ranging from 133.6 inches (3,395 mm) to 167.7 inches (4,259 mm) - and wider front/rear tracks work to improve the ride and handling. The stiffer frames, longer wheelbases and wider tracks are joined by new jounce bumpers, shock mounts and hydraulic body mounts to help isolate the road from vehicle occupants. The factory shock absorbers are usually the first items replaced by new truck buyers, but GM has installed specially valved shocks that were designed to work with the new uprated chassis and suspension, yet maintain the truck's segment-leading ride characteristics.
In the rear, GM is maintaining the AAM1150 rear axle/differential, but the U-joints used in the rear driveline are now larger, to absorb the increase in engine power and torque. The new 3" wide rear elliptical leaf springs have been redesigned to provide for an improved unloaded ride quality yet handle an increase in payload and tow ratings, which are now as high as 20,000-lb trailer towing and 6,335-lb payload - said to be segment-leading (higher than that offered by Ford & Dodge).
Higher payloads and trailer towing capability are made possible by a new braking system. New and larger brake rotors and calipers improve braking power and efficiency, with a 13% & 17% improvement in braking swept area. In addition, the hydraulic brake booster has been re-valved to provide more power to the brake master cylinder. More power assist and less brake pedal travel are said to improve brake feel and driver confidence.
Added fuel tank capacity is a welcome improvement. The new and larger 36-gallon fuel tank, combined with the fuel economy increase, extend range to as high as a bladder stretching 680-miles. Doing the math, GM's fuel economy calculations work out to something on the order of 18.8-mpg. Given the fuel price spike we all endured in 2008, and the specter of another, we're glad GM is considering fuel economy as an important ingredient in swaying future buyers. Be sure to check out a companion article that discusses the new LML Duramax 6600 and Allison in more detail.
New for 2011 is the use of the "StabiliTrak" electronic stability control system on all SRW (Single Rear Wheel) 2500HD/3500 series pickups. As discussed by the GM Powertrain engineers, the combination of StabiliTrak and the integrated electronic trailer brake controller greatly improve towing safety on rough or slippery road surfaces, and will automatically detect and prevent trailer sway. StabiliTrak controls both the truck/trailer brakes and engine management to help keep the truck and trailer under control without input from the driver. Having recently towed a heavy trailer through the mountains of Montana and Idaho in February, I can appreciate having more control.
In addition to StabiliTrak, a "hill start assist system" is now available which will automatically activate when vehicle sensors detect a grade of about 5 percent or greater. The hill start assist system will maintain braking power for about 1.5 seconds after releasing the brake pedal or until the accelerator pedal is depressed, thus preventing a rollback - even while towing.
The interiors are similar to those used in the 2007-2010 models, but subtle changes add luxury and feature enhancements. The 2011 trucks are also much safer. Aside from the newly designed chassis that builds-in safety in the event of a crash, seat pelvic/thorax and head curtain side air bags are now available on the 2500HD models. A rear backup camera and the exclusive OnStar 9.0 are optional features that can help to prevent an accident or save lives in the event of an accident.
We were told that GM may offer new sheet metal in the coming years, but for now, the GM HD pickups are the best ever, the safest ever and the most capable. Now may be the best time to order that new truck! The Diesel Page
SPECIFICATIONS
2011 SILVERADO 2500HD
Overview
Models:
2500HD reg. cab, long box, 2WD & 4WD
2500HD ext. cab, std. box, 2WD & 4WD
2500HD ext. cab, long box, 2WD & 4WD
2500HD crew cab, std. box, 2WD & 4WD
2500HD crew cab, long box, 2WD & 4WD
Body style / driveline:
2-3 passenger regular cab or 5-6 passenger extended cab,
5-6-passenger crew cab
3/4-ton; 2- and 4-wheel-drive heavy-duty pickup
Construction:
body on frame
EPA vehicle class:
full-size truck
Manufacturing location:
Flint, Mich.,
Ft. Wayne, Ind.
Key competitors:
Ford Super Duty Series pickup, Dodge Ram heavy-duty pickup
Engines
Vortec 6.0L V-8 (L96)
Duramax 6.6L Turbo Diesel V-8 (LML)
Type:
6.0L V-8
6.6L V-8
Displacement (cu in / cc):
364 / 5967
403 / 6599
Bore & stroke (in / mm):
4.00 x 3.62 / 101.6 x 92
4.06 x 3.9 / 103 x 99
Block material:
cast iron
cast iron
Cylinder head material:
cast aluminum
cast aluminum
Valvetrain:
overhead valve, two valves per cylinder, variable valve timing
