2015 GM Heavy Duty Trucks Should Silence Doubters With Real-World Prowess: First Drive

There is something very pure and quixotic about an old work truck. The bench seat, the hand-crank windows, the raw metallic sound of a tailgate slamming shut… the affordability. And the feeling that if anything goes wrong, it could be fixed with just a hammer, callused fingers, and a couple of hours in a dimly lit garage. Possibly with old friends and a twelve of Lite, with Stevie Ray Vaughn in the background.

These are not the trucks of today. And it all seemed to happen overnight.

Just as much then as they are now, pickup trucks have been a worker’s best friend, yet they have evolved to be so much more than Spartan cargo carriers. Never before have trucks been so car-like, with a suite of sound insulation, creature comforts like a heated steering wheel, new-age infotainment systems, and no shortage of active safety driver’s aids. Though, considering the sheer size of today’s trucks — especially when looking at the 2015 Chevrolet Silverado and GMC Sierra Heavy Duty trucks — it’s easy to see how features like a backup camera and proximity sensors can come in handy.

Not long ago, driving long distances in 3/4 and full-ton pickup trucks meant putting up with the drone and hum of their diesel engines and other elements that could wear on the driver over time. Not so with the GM’s new HD work horses, with the quietest cabins in the segment by far. This is because of the reworked sheetmetal, improved sound deadening, and better aerodynamics to reduce wind noise. And if we do say, they look mighty handsome, especially the HD GMC Denali, which can only be described as the trophy truck among trophy trucks. GMC does enjoy the highest average transaction price of any truck brand, after all.

So, with all this modernization of added refinement and technology, drivers of GM’s new HD machines can drive for longer distances without their senses being ground down from elevated noise, vibration and harshness levels. Long-haul drivers will enjoy this. They will also enjoy the re-calibrated suspension and throttle response. (Side note: the pedal feel of these trucks feel better when wearing boots. Work or combat will do. If you wear chukkas, go sit in a corner.)

“Whatever, man. I want my truck to be loud. Because, you know, that’s what trucks are supposed to sound like. ‘Merica.”

Sure, you’re allowed to say that. But that’s not the only thing, nor the primary reason why the 2015 Silverado HD and 2015 Sierra HD have an edge over the competition from Ram and Ford. Which, by the way, trump the GM trucks in horsepower, torque, and fifth-wheel towing. On paper, that is. More on that in a moment.

Right now, let’s focus on what it means to have a sense of control of what one is actually towing with 3/4-ton and full-ton trucks.

With a trio of very evenly evenly-matched 3/4-ton, diesel powered crew cab pickups winched up to 10,000-pound trailers; one being a 2015 Silverado 2500 HD equipped with the acclaimed 6.6L Duramax diesel engine and the other two being a Cummins-powered Ram 2500 Heavy Duty and Ford F-250 Super Duty with the new Powerstroke diesel, we descended from 5,200 feet (or exactly one mile high, where there is less air for the engine to breathe) to roughly 3,200 feet in the down a twisting, six-percent grade highway in the mountains of Arizona. This simple test demonstrated how well GM’s diesel exhaust brake system worked in comparison to the others. It also helped me understand how well each truck could handle the 10,000 pound trailer it was pulling.

10,000 pounds. That would be like pulling two or three track day cars, plus equipment. Or perhaps a trailer with about eight or nine horses, taking into account the weight of the trailer. Or a few heaping cords of lumber. Yet GM’s 2015 HD trucks are rated at pulling as much as 23,200 pounds, and we’ll say it’s the most conservative in the segment based on how well the 2500 model handled the 10,000 pound trailer compared to the Ram and Ford.

When driving downhill with the Ram 2500 Heavy Duty, cruise control engaged, one thing became quickly apparent: the diesel exhaust brake couldn’t maintain the truck’s speed. The farther down I went, the more the Ram accelerated. Eventually, I had to intervene with manual braking and downshifting. The same could be said of the Ford. More alarmingly, it felt like the trailer was the one doing the driving — more so with the F-250 — which had me decelerating more than I would have liked just to gain control.

The Chevrolet HD, meanwhile, was able to maintain its speed downhill with its diesel exhaust brake and cruise control when the others couldn’t, and was able to manage its trailer significantly better than either the Ram or Ford. You wouldn’t think it reading the spec sheet, being the underdog in rated torque, horsepower and fifth-wheel towing, but the Chevy outclassed both its rivals in this real-world action.

Going back up the 6-percent grade revealed that rated horsepower doesn’t mean nearly as much as power delivery. With a clearing in traffic, the Silverado HD, with its 397 horsepower and 765 lb-ft of torque, lined up next to the Ram 2500 Heavy Duty and its 385 horsepower and 850 800 lb-ft of torque, matched mirror to mirror at 35 mph, and with a signal, accelerated back up to 60 mph. The Ram, with the mightiest engine rating of the bunch, was shamed. The 400 hp, 800 lb-ft Ford Super Duty put up a more even fight, but seemed to run out of steam in the higher revs, and that’s where the Chevrolet pulled away.

As an aside, we’re not sure how Ram can get away with saying its 3500 model can tow 30,000 lbs when the 2500 model with a slightly de-tuned variant of the same engine can barely accelerate up a hill with a third of that weight. The adoption of the J2807 SAE standard cannot come soon enough.

In short, the demonstration points to the following conclusions: if you just want the sales leader and nothing else, consider the Ford Super Duty. If you want the loudest truck of the bunch and want to brag about numbers on paper, consider the Ram Heavy Duty.  But if you’re serious about your hauling and towing, and value real-world testing and data over what automakers claim, consider either the 2015 GMC or Chevrolet HD trucks.

As a reference, GM’s 2015 HD trucks feature a segment-leading max payload rating of 7,374 pounds; and maximum available conventional towing is 19,600 pounds, which is also best in class, thanks to a special hitch mount. Meanwhile, maximum available fifth-wheel towing is 23,200 pounds. Which is probably more than anybody is going to rationally pull with a truck of this caliber. Because at that point, a commercial medium duty truck might be an option, as well.

On the drive up into the mountains, I was able to drive one of the only GM HD trucks equipped with the naturally aspirated 360 hp, 380 lb-ft 6.0L Vortec base engine. It’s power delivery is smooth, but there’s not much of it when tasked with moving a vehicle of this magnitude. It also felt worked climbing up the mountains. That said, we don’t expect the motor to make it in the next refresh, which is expected to bring a new frame and engines. But for now, what GM is currently offering is more than sufficient, especially with the tried-and-true Duramax-Allison powertrain.

… If only they could actually fit in the garage.