Epitome of Refinement: The 2017 Chevy Silverado HD is as Polished as It’s Ever BeenPosted in Features on August 9, 2017
The heavy-duty pickup scene is a busy place these days. With diesel engines packing 900 lb-ft of torque, commercial-grade six-speed automatic transmissions, and towing and payload capacities perpetually climbing skyward, there is little left to be desired on these mountain movers. In fact, before any of the Big Three’s latest truck offerings even begin to break a sweat you’ll need to obtain a commercial driver’s license. Think about that…
As for the ’17 Chevrolet Silverado 2500 and 3500 HDs, GM opted to perfect its existing chassis, debut an all-new Duramax powerplant, and leave the GCWR number chasing to Ford and Ram (for now). While this move might seem submissive, we can assure you that it’s anything but. With the majority of its customers towing between 10,000 and 20,000 pounds, it only made sense to further refine its product for its target audience.
To find out exactly what the ’17 Silverado was made of, Chevrolet invited us to a ride-and-drive event cohosted by John Deere in the Quad Cities area of northwest Illinois and southeast Iowa. While there (CDL in hand), we were able to get behind the wheel of 2500- and 3500-model trucks that had been loaded to their maximum GCWR. Throughout our testing, it was clear that the latest Silverado is as polished and capable as it’s ever been.
Without question, the all-new Duramax diesel is the headline for the ’17 Silverado HDs. Thanks to a complete redesign, the L5P-code 6.6L V-8 produces a class-leading 445 hp at 2,800 rpm and an incredible 910 lb-ft of torque at just 1,600 rpm. To stand up to the elevated cylinder pressures required to achieve that torque figure, the deep skirt, cast-iron block is heat-treated for a 20 percent improvement in strength. The connecting rods, equipped with larger bearings and beefier wrist pins than predecessor engines, are 20 percent stronger as well. In addition, for the first time since being introduced in 2001 the Duramax does not utilize a Bosch common-rail fuel system. Instead, Denso G4S Gen III solenoid-style fuel injectors and a Denso HP4 injection pump will handle high-pressure fuel supply (up to 29,000 psi). An electronically controlled and actuated, variable geometry turbocharger takes care of aspiration, forcing boosted air through an air-to-air intercooler before making its way into the highest flowing set of aluminum cylinder heads to ever grace a Duramax.
The Full Scoop
For anyone out there in reader-land still wondering, yes, the hood scoop is fully functional—but also 100 percent necessary. According to the folks at Chevrolet, the L5P Duramax receives roughly half of the air it needs through the hood scoop. To keep moisture and airborne debris from entering the intake tract, incoming air is routed through an expansion chamber whereby liquid(s) and heavier debris settle in the bottom (and escape via draining to the atmosphere) while air is allowed to flow through to the engine. The chamber itself is essentially self-cleaning, although an integrated plug exists for removing larger debris. In environments where the ambient air temperature is excessive and the engine is working at maximum load, you’re bound to see more heat (namely elevated exhaust gas temperature). This passive cold-air intake system provides for controlled intake air temperatures to enter the engine at all times so the truck never experiences a de-fuel scenario (where the ECM pulls power in order to keep the engine safe).
The tried and true Allison A1000 automatic will remain the sole transmission option behind the Duramax, albeit with several updates to cope with the newfound torque. Among the six-speed’s key revisions is a larger output shaft and an upgraded torque converter with added holding power. The clutch packs, input shaft, and intermediate shafts are all carryover items, while driveline reinforcements come in the form of larger U-joints. From our own observations (independent data gathered at the drag strip), only a 12-14 percent drivetrain loss in power occurs on the ’17 trucks—a testament to the Allison’s power-transfer efficiency.
Unloaded, the ’17 Silverado HD is hands down the quickest truck in the heavy-duty segment. In fact, Crew Cab, shortbed, 4x4 configuration 2500 models are capable of sprinting through the quarter-mile in 14.8 seconds. While not impressive by today’s sports car standards, that type of giddy-up is proof positive that just under 400 of the engine’s 445 ponies makes it to the wheels. In our time behind the wheel, we noticed a touchier accelerator than what we found on the ’11-’16 trucks. Chevrolet disclosed that less spring tension is now employed on the accelerator pedal, which means less throttle input is required to accelerate. Couple that touchier accelerator with 910 lb-ft of torque being available as early as 1,600 rpm, and it’s easy to see why the new Silverado 2500 HDs can go from 0-to-60 in just over 6 seconds.
Built to Tow
As most of us know, the days of GM’s HD trucks getting pushed around by a loaded trailer faded with the release of the ’11 model year Silverado and Sierra, which sported a fully-boxed frame, 3-inch-wide asymmetrical leaf spring packs, and a beefier independent front suspension. Building upon that chassis redesign—and knowing that when its customers hook to a trailer they’re usually towing one of their most prized possessions—the ’17 trucks take things a step further in terms of controlling loads. The combination of an exhaust brake, quick-reacting integrated trailer brake controller, and a Tow/Haul mode that has all but been perfected culminates in a relaxing towing experience, regardless of what you have in tow. The ’17 Silverado HDs may not have the edge in the GCWR war, but they certainly feel right at home when towing at or near their maximum capacity.
Pushing the (Legal) Limit
To get an idea of just how capable the new Silverado is, Chevrolet loaded a 33-foot tandem axle Big Tex gooseneck trailer with a 310L John Deere backhoe and attached it to one of its Crew Cab, dual rear wheel 3500 models. The combination brought the truck within 1,000 pounds of its maximum GCWR of 31,300 pounds. While no pickup ever really appreciates being saddled with that much weight, the truck’s chassis didn’t seem to mind, the Duramax had no problem getting the load moving, and the Allison always gave us the right gear for the given driving situation. However, we were much more impressed with how well the dualie was able to bring all that mass to a halt. Between the integrated trailer brake controller, firm yet smooth engagement of the exhaust brake, and aggressive downshift strategy of the Allison when in Tow/Haul mode, stopping 30,000 pounds worth of truck and trailer felt very surefooted.
Pushing the conventional trailer tow rating of its 3/4-ton model (13,000 pounds, in this case), Chevrolet also invited us to pilot a Crew Cab, shortbed, 4x4 Silverado 2500 HD. The load consisted of a John Deere 324E skid steer strapped to an 18-foot tandem axle trailer, also supplied by Big Tex Trailers. For this test, the Duramax/Allison combo was definitely in its element from an acceleration standpoint. Merging onto the interstate and overtaking other vehicles could be accomplished with little effort. Stability was what you’d expect from a single rear wheel, 3/4-ton pickup toting a compact piece of equipment down the highway—not nearly as good as a dualie, but sufficient enough to get the job done. Just as was the case with the dualie, the exhaust brake, integrated trailer brake controller, and engine braking (courtesy of the timely downshifts you get with the Allison in Tow/Haul) worked flawlessly. Add to that an improved service brake pedal feel (it’s much stiffer than on ’11-’16 models), trailer sway control, and digital steering assist and a lot of the chore work has been removed from the towing experience.
Fine-Tuned Exhaust Brake
Since 2011, GM has offered an exhaust brake on its diesel-powered Silverado and Sierra HDs. Now with six model years under its belt, the exhaust brake function is as refined as it’s ever been. Its performance is smoother than what you’ll find on Ram 2500 and 3500 models, yet more aggressive than what we’ve experienced on the ’17 Super Duty. Technically a turbo brake, the exhaust brake takes advantage of the variable geometry turbocharger’s ability to restrict exhaust flow leaving the turbine (exhaust) housing and uses that capability to decelerate the truck. The exhaust brake helps make the descent on the backside of any mountain a comfortable and safe experience—especially when used with the aforementioned integrated trailer brake controller and the transmission’s effective Tow/Haul mode.
Multiple Vantage Points
Chevrolet’s trailering camera system allows you to keep tabs on your trailer from several angles. Visibility comes by way of cameras mounted within each side view mirror housing, a trailer-mounted unit, and an optional third brake light camera. The trailer-mounted camera is designed to be placed at the rear of your trailer for utmost safety when backing, and is hardwired into the trailer lights. The trailering camera system also fully integrates with the Silverado’s infotainment system and provides imagery from up to four different cameras simultaneously. Our favorite feature is the fact that the side view mirror cameras are activated anytime you use your turn signals.
Of course, a top-of-the-line High Country model—equipped with nearly every bell and whistle offered in Chevrolet’s arsenal—was on hand for everyone to drool over. Available only in Crew Cab configurations, the High Country trim level includes 17-inch, polished forged-aluminum wheels on dual rear wheel models (shown) and 18-inch chromed-aluminum wheels on single rear wheel 3500s. A unique grille, paint-matched front and rear bumpers, and 6-inch-wide chrome running boards are also part of the deal, while a choice of Saddle or Jet Black interior, heated and vented custom leather-appointed front seats, center floor console, and a Bose premium audio system highlight the list of luxuries found in the cab. A spray-in bedliner is also included in the High Country package, complete with a full-on Chevy logo. And, who could forget the wireless charging pad for your smartphone?
Comfortable and Quieter Cab
The diesel rattle is officially gone as far as Chevrolet heavy-duty trucks are concerned. Thanks to the use of inlaid, triple-sealed doors, an acoustic windshield, and various other measures taken to limit in-cab noise, the ’17 HDs are ultra-quiet. Under the hood, sound-deadening rocker covers and the new injection system’s use of multiple pilot events make the diesel clatter extremely faint. Aside from a slight hint of compression ignition at idle, the average Joe might not even know a Duramax exists under the hood. As for comfort, the same cab that debuted in ’15 is in use with its added legroom in Crew Cab configurations, along with double cab models receiving forward-hinged rear doors. Lastly, dual-firmness foam seats help alleviate fatigue and offer added support.