If you've been paying attention to new truck releases, you've no doubt seen photos of the latest Chevy and GMC Heavy Duty trucks. Ever since their unveiling at the Chicago Auto Show, all of us at Truckin' have been eagerly awaiting our chance to put one through its paces. Our waiting finally ended at a media event that began in Baltimore, Maryland, and had us travelling across three states, racking up over 500 miles in the latest 2500 and 3500 models from Chevrolet and GMC.
Upon first glance, the 2011 HDs look a lot like their 2010 counterparts, but inexplicably more brawny. New bumpers, grilles, and hoods are responsible for the improved looks, but like your mom always said, "it's what's inside that counts," and the new chassis is responsible for not only an improved stance that's a bit wider, but the enormous strides made in capability. Before we can tell you how the trucks stack up against their competition, we need to explain exactly what the freshened-up bodywork is hiding, or "keeping dry" as the chassis and powertrain engineers like to say. GM has 45 percent of the 3/4-ton market but only 28 percent of the 1-ton market. They knew that the payload and towing capability of their 3500s was trailing Ford and Dodge, so they beefed up their chassis and powertrains to offer class-leading payload and towing in several cab configurations, not just one oddball model. Underneath it all, the HD chassis is 99.9 percent new. Until now, the HD trucks used a frame that carried over from the previous-generation HD trucks. Not anymore. A fully-boxed frame that has five times the torsional rigidity of the old HD frame made it easier to tune the suspension, and chassis engineers did just that, with five unique torsion bars depending on cab configuration. Yes, the HDs retain independent front suspension (IFS) in their 4WD models, unlike the Ram HD and Ford Super Duty which rely on a live axle. GM believes that IFS gives them the edge in ride and handling. It does. Their strengthened front axle, with Gross Axle Weight Ratings (GAWR) of over 6,000 pounds, allows for snowplow equipment to be attached to the front of any of their 4WD model and gives users the ability to tune ride height after the heavy equipment has been bolted on. By the way, the 0.1 percent of the chassis that remains, which is my math, not theirs, are the two sway bar end links in the front suspension.
After flying into Baltimore, we had a little over 130 miles from the airport to our destination at the Rocky Gap Lodge in Flintstone, Maryland, but we chose to simply ride as passengers for this portion and sling questions at the GM engineer sitting in the back seat, rather than drive. With 2,000-lbs of ballast in the bed, our 2500 rode amazingly well. We don't often find ourselves in luxury cars, so we can't quite make that comparison, but the ride felt as good or better than any 1/2-ton we've been in. The following morning, we had our first shot behind the wheel on the HD pulling a 9,500-lb camp trailer up and down the steep and winding grades of western Maryland. We were actually warned that this part of the drive should be reserved for those of us with trailering experience, but we've hauled vehicles on trailers, so we figured it would be a cinch. It turns out that the roads were narrow and we were on our toes with oncoming lumber trucks taking more than their share of the road. The engine braking of the Duramax's variable-geometry turbo dramatically reduced the amount of downshifting necessary on the steep grades we encountered and wasn't intrusive, but when we did need more braking, a tap on the pedal would let the Allison transmission know what we wanted. If more braking was needed, another tap got us another downshift. It impressed us, as well as several other drivers, with how intuitive the system worked. We don't really have much else to say about the new Allison six-speed transmission, and in our opinion, that's a good thing. When it comes to towing, we don't want to think about gear selection if we don't have to, and once we pulled the shifter into "D" and hit the tow/haul button on the dash, we didn't have to. Improved shifts and additional clutches increased the capacity of the Allison to match the Duramax, and they work perfectly together.
Unfortunately, for all of the engineers that worked so hard getting the Allison to work seamlessly and be more efficient, the Duramax stole the show. It's been on the scene for 10 years now, and it's no stranger to the diesel community. The aftermarket welcomed it with open arms, as did a large number of drag racers, sled pullers, and everyday, average trailer users. The LML is definitely worthy of carrying the torch for the current HD trucks, it's nothing short of a beast. Merging uphill onto highways was not a problem, even with a big load behind us, as the Duramax pulled steadily no matter the engine speed. The fact that Duramax engineers were able to coax an additional 30 hp and 100 lb-ft out of the same engine platform is impressive, but the fact that the new engine is quieter, cleaner, more fuel efficient, and under no more stress than previous versions is proof that this wasn't just a simple engine software upgrade. With new injectors, pistons, bearings, and oiling characteristics, the LML Duramax offers several small, but significant, upgrades over the previous generation. The only new factor that owners will have to deal with is the Diesel Exhaust Fluid (DEF) system that reduces the Duramax's NoX emissions by over 60 percent. A 5.3-gallon tank under the passenger-side footwell is accessed through a filler neck under the hood, which is appropriate since the fluid will only need to be topped off every 5,000 miles (about every oil change). Further improvements in the emissions system include a diesel particulate filter system with an extended regeneration cycle. The system can go as far as 700 miles before the downstream injector supplies extra fuel to clean the filter. The extended regeneration cycles cut fuel usage, and the use of a downstream injector keeps additional unburned fuel from seeping past the rings and contaminating the oil.
Another improvement that was soon appreciated was in the steering. We didn't have a 2010 Chevy HD on hand for a direct comparison, but a quicker steering ratio and larger steering gear eliminated any play and felt nicely dialed in. The steering response, engine power, engine braking, and exhaust brake all translated to immediate driver confidence. The truck never got out of balance or felt like it had a mind of its own. In fact, we set the cruise control and let the truck handle the speed going up as well as going down the 8 percent grades, making for a relaxing drive even though we had over 35 feet of trailer hanging off the back.
After a suggestion from a colleague, we drove identical loops back-to-back, first with 2,000 pounds in the bed of a single-rear-wheel Chevrolet 3500 4x4 with the brand-new Duramax and then again with 2,000 pounds in the bed of a single-rear-wheel Ford F-350 4x4 with Ford's brand-new Power Stroke. Both trucks are remarkably powerful. Chevrolet and GMC have the bragging rights for now with a 7 hp and 30 lb-ft advantage over Ford, with 397 hp and 765lb-ft of torque, so both have enough power to haul just about any tool or toy you'd care to load on a trailer, and it's practically too close to call from the seat of the pants feel. What's easier to perceive is engine noise and ride quality. Cruising on an even stretch of highway with the engine at around 1,700 rpm you'll struggle to hear the Duramax, while the Power Stroke has a noticeable rumble as well as turbo whine. We didn't really mind the engine noise from the Ford on our short time behind the wheel, but it's one of the factors that GM engineers addressed in their HDs to reduce driver fatigue. The fewer distractions and annoyances, the better. As for ride and handling, the IFS certainly has its advantages compared to the solid axle front suspension in the Ford and Ram. IFS allows for a better contact patch for steering and braking, and obviously each side can react to bumps on its own. On the relatively new asphalt highways we were on the difference was subtle, but noticeable. Where the Ford and Dodge solid axles prevail is in the sort of off-road environments where extreme wheel travel and low speeds are the way to go, but on the highway there's no question that IFS rules. Before we get hate mail from Ram HD or Super Duty owners, we're not trashing the ride of your trucks, we put thousands of miles in a Ram HD earlier this year and didn't have a complaint,-it's just that these trucks are even better in that regard.
With so much attention paid to the Allison's shifting to take advantage of engine braking and the turbo's exhaust braking, we hardly had cause to test the truck's traditional brakes. Remember, I said hardly. With 14-inch rotors on each corner that are thicker than before, stiffer calipers, and revised hydraboost calibration, the 2011's pack some powerful binders. On our final driving session of the trip we stepped into a Duramax crew cab dually that was carrying 2,000 pounds in the bed and had over 10,000 pounds of skid steer loader on a conventional trailer. My copilot, so confident in my skills and so comfortable in the passenger seat, fell asleep (he obviously doesn't know you well-Ed. Dan). The ride was completely uneventful and I felt perfectly at ease towing the heavy trailer, but a wayward tourist was bound and determined to shake things up. The confused driver, who was nearly totally committed to exiting the highway, changed their mind and their lane, simultaneously it seemed, into the one we were occupying. I'd use the term "merge", but that would imply at least some attempt on their part to match our speed. I don't know how an earlier version of the HD would have handled the situation, but the truck didn't miss a beat as we were able to quickly reduce our speed without any unexpected feedback from the truck or trailer and all parties were able to continue unscathed. Uncharacteristically, I didn't even feel the need to shout obscenities.
No doubt the Chevy and GMC faithful will fall in love with the newest iteration of their HDs; they've improved on everything that they already had done quite well, but will this new HD pry owners out of their Ram HD or Super Duty? Even GM's engineers and marketing admit that Ford and Ram offer competitive products, in fact they enjoy the rivalry because competition drives them all to produce the best product they possibly can. What GM focused on was trying to capture the segment of the market that they call "free agents", those buyers who aren't fiercely brand loyal. Never has their decision been more difficult, as the Big 3 have some amazing HD offerings, but if ride quality, steering feel, and driving confidence are high priorities, we can easily see them with one of the General's new HDs in their driveway.