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.