2017 GMC Sierra 3500HD Review

One of the most appealing versions of the 2017 GMC Sierra 3500HD is the SLT trim level, especially when equipped with the optional 6.6-liter turbodiesel engine. The SLT comes with items such as leather upholstery and power-adjustable pedals, and with the diesel engine you can tow almost anything...

The six-speed automatic transmission is mostly smooth, but the 1-2 upshift can be abrupt. And it's smart, letting the engine's massive torque do the work instead of downshifting. In town, throttle pedal action is supple and the brakes are never touchy.

Even before recent updates, the Sierra's optional diesel engine was the one to get. It had smooth, nearly instantaneous power delivery at all times. We expect this new engine to be even better.

In everyday driving, the brake pedal action is pretty linear, but at times the slightly spongy pedal makes it feel as if the brakes aren't all that strong. Our track-tested panic-stop distance from 60 mph — 144 feet — is a bit longer than average for the segment.

For such a large, heavy-duty truck, there's good steering, with good weighting (typically it's too light) and some feedback. It's a slow ratio, though, which means it requires several rotations of the wheel to get it around corners on back roads.

Handling is aided by precise steering and well-controlled body roll through corners. The suspension reacts pretty well to midcorner bumps. You don't buy a heavy-duty truck for its handling abilities, but it's nice to know that this one isn't a slouch around turns.

The six-speed automatic transmission is mostly smooth, but the 1-2 upshift can be abrupt. And it's smart, letting the engine's massive torque do the work instead of downshifting. In town, throttle pedal action is supple and the brakes are never touchy.

With the Z71 suspension package (which our test truck had), you get upgraded shocks, underbody shields, hill descent control and doorsill plates. It's no rock-crawler, but with a competent four-wheel drive and a low-range transfer case it's a very capable off-road machine.

Everyday comfort in the 3500HD is pretty good overall. The seats aren't quite as comfy as those in rival trucks, but they're still quite nice. We are impressed with how quiet the cabin is.

Despite thick padding, the front seats aren't all that plush, and the seatbacks in particular are on the hard side. The rear seat cushions feel softer than the front ones and envelop you more. The rear seatback is at a nice angle for all-day riding.

Considering the heavy-duty Sierra was designed with towing and hauling in mind, it's a decent-riding truck. You'll get some of the typical jiggling on concrete freeways (especially when the truck's unloaded) and big bumps upset it, but overall it's pretty livable.

This is an impressively quiet truck. The previous-generation diesel had a bit of ever-present clatter, especially when cold and at low speeds, but it was never obnoxious. There's hardly any wind noise, and the big truck tires don't sound like big truck tires.

There are high-quality materials, a large amount of space and plenty of storage areas inside the 3500. We love the optional damped tailgate's action, as well as the integrated bumper step.

The instrument panel is legible and clear, and the IntelliLink touchscreen responds relatively quickly to inputs. Buttons and knobs are generously sized and intuitive. Cruise control can overshoot your desired speed downhill, though, even when the "smart" exhaust brake is invoked.

As with pretty much any heavy-duty truck, the Sierra sits high. It's a definite step up to get in, but entry is made easier thanks to the optional running boards and the standard grab handles at each door.

Up front, there's enormous amounts of headroom and plenty of space to stretch out sideways. It would be nice if there was a dead pedal as a resting spot for the driver's left foot. There's tons of rear headroom with excellent foot space underneath the front seats.

For a 3500 series truck, the front windshield pillars are refreshingly narrow. But the roof pillar behind the driver and the grab handle restrict the driver's lane-change view, and the rearview mirror and side mirrors could be larger. Otherwise, this is an airy cabin with tall side windows.

Few owners will ever get near the theoretical tow limit of a truck as capable of the GMC Sierra 3500HD (in most places, you'd need a commercial license just to tow that much). However, with its newly revised diesel engine it has some of the top towing numbers in the class.

There's a large center-console storage compartment that doubles as a big armrest, cupholders at every turn, and plenty of pockets for whatever you've brought along. This truck can tow the big things and haul plenty of the small stuff, too.

A large cabin with a fold-up 60/40-split rear seat means there's plenty of room for tools or whatever other precious cargo you'd like to keep locked up inside. There are also a number of optional tonneau covers for the back if that's where you'd rather store your things.

The Sierra 3500HD with the optional 6.6-liter turbodiesel can tow up to 20,000 pounds with a trailer hitch, or 23,300 pounds with a gooseneck/fifth-wheel — both of which are impressive numbers.

GMC's IntelliLink infotainment system was improved in 2016 with faster processors and Apple CarPlay and Android Auto functionality. The navigation display similarly impresses with easy address input and readable graphics.