There's a particularly trite and overused phrase we've heard so often we no longer respond when someone utters it: "You can't judge a book by its cover." And it's baloney, too. War and Peace is a tough read because it has so many damn pages, is old and weighs a lot. Cats for Dummies is something less than high art and will not soon become a major motion picture.
But a lesser-known corollary to this adage actually works: "You can't judge the profound changes in the capability of a heavy-duty pickup truck by the freshness (or lack thereof) of its sheet metal and interior."
Haven't heard that one? Jim Mikulec, GM's lead development engineer on the 2011 Chevrolet Silverado HD and GMC Sierra HD project, puts it another way: "Everything that's changed is under the skin. Everything that's important is under the skin."
Falling Down
Just four years ago, the 2006 Chevrolet Silverado 3500HD dually defeated Ford Super Duty and Dodge Ram HD trucks in our straight-up fight of strength and towing capability. Despite an aging interior, it won largely on the strength of its 6.6-liter Duramax turbodiesel V8 engine and class-exclusive six-speed Allison automatic transmission. In 2007 GM gave its HD pickups a long-overdue body and interior redesign to go with these then-impressive mechanicals, and for the next couple of years the Chevrolet Silverado HD and GMC Sierra HD twins stood atop the pile.
But the competition would not stand for this. Neither would they sit idly by or take it lying down. We're not sure what it looks like when you're not standing, sitting or lying down, but it apparently involves lots of engineers and money.
Dodge engineers countered first by upping the displacement of the Cummins turbodiesel from 5.9 to 6.7 liters in 2007 and replacing the archaic four-speed automatic with a much-needed six-speed a year later. For 2010 they added new sheet metal and a long-overdue crew cab to the lineup, and the Ram HD vaulted to the front
Ford's brainiacs leapfrogged ahead mere months later after introducing a revolutionary 6.7-liter PowerStroke V8 turbodiesel and a brand new six-speed automatic to handle the new mill's 390 horsepower and 735 pound-feet of torque. The 2011 Ford Super Duty got a final cherry on top in the form of significant upgrades to the interior electronics.
In less than a year, the Chevrolet Silverado HD tumbled from first to worst. Enter the 2011 Chevrolet Silverado 3500HD.
Skeletal Reconstruction
Looking at it, the 2011 Chevrolet Silverado HD seems little different from 2010 versions. The bodywork and interior are essentially unchanged because GM focused its engineers and money on the areas where the Silverado HD lagged behind the competition: payload and towing capacity.
But the GM brass didn't want to merely improve their 2011 Chevrolet and GMC HD trucks. They wanted them to have best-in-class towing and hauling performance, or as Chief Project Engineer Mark Cieslak told us, the goal was to "take the segment."
To accomplish this, carryover bodies would sit atop a completely new frame and suspension designed to support class-leading ratings for GVW (gross vehicle weight) and GCW (gross combined weight).
The resulting clean-sheet frame is built from rails that are both taller and wider, and you won't find any open c-sections because this frame is now fully boxed from end to end. The rails themselves feature more gradual bends, and the crossmembers are stouter, more numerous and tend to be welded in place instead of riveted.
It has paid off big-time. The resulting structure is 92 percent stiffer in bending and nothing less than 500 percent stiffer in torsion than the outgoing frame.
Suspension Beef
A frame like this permits the use of a suspension that can handle higher loads and absorb impacts more efficiently, and GM has taken full advantage with clean-sheet designs for both the HD's front and rear suspension.
In front, the 2011 Silverado HD retains its fully independent double-wishbone layout and the built-in ride and steering advantage it provides over the solid-axle competition. But all of the pieces are newly designed and significantly beefier — the single exception being the stabilizer bar's drop link.
The lower control arms are stouter while the upper control arms, now forged from steel instead of stamped, have been moved upwards to a high-mount position. Heftier torsion bar springs, revalved shocks and dual urethane bump stops allow the front gross axle weight rating (GAWR) to increase to 6,000 pounds on 4x4 versions, a move that allows GM to offer the snow-plow prep option on any 2011 Silverado HD or Sierra HD 4x4 model, regardless of engine choice.
The beefiness extends to the braking system, where 14.0-inch cast-iron brake rotors replace the 12.8-inch units used last year. To ensure proper caliper clearance, this move dictates a minimum wheel size of 17 inches instead of 16 inches. Optional 18- and 20-inch wheels are also on the menu.
Back-to-back drives in the Silverado HD against a Ford F-350 on the open road clearly demonstrated the ride comfort of the Silverado's independent front suspension with its relatively low unsprung mass. But that we expected; it was the brakes that gave us a pleasant surprise. Turns out Chevy engineers didn't like last year's long, soggy brake pedal any more than we did, so they made welcome improvements to the pedal ratio and the hydro-boost assist characteristics to improve response.
Payload Payoff
Out back, the leaf springs are now 3 inches wide, up from 2.5 inches before. The projecting forward half of the springs has been shortened to make the leaves asymmetrical front to rear, a move that reduces axle windup at launch. Urethane rear bump stops replace hard rubber ones, and every mounting bolt in sight has been upsized.
The result is a 1,175-pound increase in rear GAWR from 8,200 to 9,375 pounds. This plus the aforementioned front-end improvements allow a hefty 1,600-pound GVWR increase to 13,000 pounds.
The latter now equals the Ford F-350's GVW rating, but Silverado curb weights tend to be lower, leaving a larger surplus for payload. The top payload of the Silverado 3500HD, the so-called "1-ton" truck, is 6,635 pounds, 1,380 pounds more than last year. Ford's F-350 tops out at 6,520 pounds. In all, Chevy has five 3500-series models with payloads topping 6,000 pounds. Ford has one.
It's much the same on the "3/4-ton" side, where the max payload of 4,192 pounds is one of 13 Chevrolet 2500HD configurations that are rated to carry more than 3,100 pounds. Ford's F-250 offers one such rating. (Ouch.)
Weight Underway
That's the payload side, but it takes more than a stout chassis to support increased trailer weight. As good as the 6.6-liter Duramax had been in the old truck, 365 hp and 660 lb-ft of torque wasn't going to cut it against Ford's new 6.7-liter Super Duty turbodiesel.
No worries. Chevrolet powertrain engineers found another 32 horses and 105 lb-ft, allowing the revised Duramax 6.6-liter turbodiesel to best the Ford's output with a class-topping 397 hp and 765 lb-ft of torque.
The 6.6-liter displacement and 16:1 compression ratio are unchanged. The output increases come instead from a new set of 30,000-psi piezo injectors, a selective catalytic reduction (SCR) system and, more to the point, careful tuning of the engine calibration and turbo-boost map to meet new diesel emissions regulations and testing methods.
Like most other modern clean-diesel emissions technologies, the SCR system injects tiny amounts of the increasingly familiar diesel exhaust fluid (DEF) to react in the SCR catalyst, reducing NOx in this case by some 63 percent. The Silverado's new DEF tank holds some 5.3 gallons, enough for 5,000 miles.
A same-sized variable-nozzle turbo is used, but it's been altered to provide a computer-controller engine braking function, not unlike the system that recently appeared on the Ford Super Duty diesel trucks. Chevy's version differs in that it has an on-off switch and utilizes four maps to optimize performance in the four possible combinations of cruise control on-off and tow/haul on-off.
Through it all, GM claims the new Duramax is up to 11 percent more fuel-efficient than last year's model. Heavy-duty pickup trucks aren't subjected to official fuel economy testing, but GM claims a 680-mile highway range on a 36-gallon tank of diesel. That works out to 19 mpg — unofficially, of course.
It all adds up to a significant increase in the 2011 Silverado's GCWR, the limiting factor when it comes to towing capacity. Last's year's GCWR topped out at 23,500 pounds, leaving 16,500 pounds of maximum 5th-wheel towing capacity. This year's GCWR leaps to 29,200 pounds, dragging the maximum tow rating along with it to 21,700 pounds, a convenient 100 pounds more than the Ford F-350 Super Duty.
Trailer in Tow
The proof, of course, is in the towing. We didn't get a chance to drive on our familiar desert test grade, but we were able to make back-to-back comparisons to a similar Ford F-350 diesel with equal 9,000-pound trailers attached.
In short, Ford and Chevy have themselves a horse race, and Chevy seems to have a slight advantage. Both towed the admittedly lightweight trailer up the admittedly short grade in an equally relaxed manner at part-throttle, but the Chevrolet 3500HD got off the line a tad quicker and ultimately produced less diesel rattle on the steeper sections.
But the rolling terrain of western Maryland was good for demonstrating just how superior the downhill grade logic of the six-speed Allison transmission really is, especially with the exhaust brake added into the mix. The Ford Super Duty was good, but the Silverado HD felt better.
But these conditions weren't particularly challenging or definitive. It wasn't hot, the grades weren't steep or long and, most of all, the supplied trailer didn't bring either truck close to its considerable limits. These heavy-duty machines deserve nothing less than a full rematch on home soil. Don't worry. We're already making plans.
Unfinished Business
We recognize that GM made a logical business decision when it focused its attention on the skeleton and guts of the 2011 Chevrolet 2500 and 3500HD trucks. And we don't really have a problem with the old exterior of this new truck. Minor tweaks to the bumper, grille and hood have made a good-looking rig even more handsome.
But the interior, it needs help. The 2010 Ram HD is all-new in this regard, with a very handsome cab adapted from the universally praised Ram 1500's interior. The 2011 Ford Super Duty's cab isn't particularly new, but the basic design is sound and it is aging quite well thanks to the addition of a very clever new instrument panel and the much-praised Sync infotainment system.
By comparison, the Chevy and GMC interiors are built well enough, but there appears to be a lot of wasted space. Also the switchgear is small, particularly on the center stack, with lots of same-sized buttons in close proximity. Tiny air-conditioning icons highlight our growing need for bifocals, and the control switch for that excellent exhaust brake has a status indicator light that's impossible to see in daylight. There's room for improvement here.
But Still...
There is no denying that the 2011 Chevrolet Silverado 3500HD is a great truck. The things that matter most in this segment — engine, chassis, suspension — have been thoroughly upgraded under the skin. It's nothing less than a heart-lung-brain-skeleton transplant, with stitching so expert we can't see the Frankenstein seams.
An LT-grade Chevrolet 3500HD 4x4 dually starts at $42,885. Add the Duramax diesel engine and Allison transmission ($8,395) and the price rises to $50,880, about $500 less than a Ford F-350 XLT dually 4x4 with a V8 diesel and six-speed automatic. Dodge Ram 3500 SLT prices reside in the same ballpark.
For the time being, at least, the 2011 Chevrolet 3500HD can boast the largest towing capacity, the highest payload and the healthiest engine output in the 1-ton segment. But that's sure to change when the competition throws yet more engineers and money at their respective trucks. After all, as another over-used saying goes, "This is war!"
Edmunds attended a manufacturer-sponsored press event to facilitate this report, which originally appeared on insideline.com.
