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2018 GMC Sierra 3500HD: New Car Review

The 2018 GMC Sierra 3500HD charges into showrooms this year virtually unchanged from last year, which saw the introduction of the stump-pulling 6.6-liter Duramax Diesel as an optional powerplant. With a powerful available diesel in play, the Sierra offers the best of both big truck worlds. It can work hard by day and impress the gentry when the sun goes down. Even in its entry-level grade, it’s an impressive show pony. Really jazz it up with the upscale Denali trim and you’ve got a luxury people hauler featuring a cabin with loads of space and premium materials.

Breathing rarefied air, the 2018 GMC Sierra 3500HD has but two competitors beyond its Silverado cousin: the Ford F-350 Super Duty and the Ram 3500 HD. Unless a consumer is a die-hard GMC loyalist, some cross-shopping is inevitable; but the Sierra 3500HD stands on its own. It does everything it should do and does it well. And the wildly popular Denali grade tosses in a bit of added luxury to boot.

What’s New for 2018?

The Sierra HD now provides a standard backup camera on all grades; MyLink with 7-inch display is standard on base model

What We Like

Massive towing and hauling capabilities; strong Duramax diesel engine; user-friendly technology; multiple parking and towing cameras; classy Denali model

What We Don’t

Rivals technically have greater towing capacity; no self-leveling suspension such as with the Ram HD

How Much?


Fuel Economy

The 2018 GMC Sierra 3500HD offers two engines. The truck’s standard power plant is a 6.0-liter V8 making 360 horsepower and a muscular 380 lb-ft of torque. Although capable, that engine is hugely outdone by the optional 6.6-liter turbodiesel V8, producing 445 hp and 910 lb-ft of torque. A 6-speed automatic is standard with both.

Since the Environmental Protection Agency doesn’t provide fuel economy ratings for vehicles as large as the Sierra 3500HD, official gas mileage numbers are unavailable, but these trucks aren’t for buyers interested in saving fuel. When unloaded, most drivers will see around 14 miles per gallon in combined driving.

Standard Features & Options

The 2018 GMC Sierra 3500HD comes in a wide variety of trim levels, body styles and configurations. There are Regular, Extended and Crew Cabs, along with regular beds and long beds, gasoline and diesel engines and 2- and 4-wheel drive. Drivers can also choose between two rear wheels or four (a "dually"), depending on their desired payload capacity.

As for trim levels, the Sierra starts with a base model simply called the Sierra ($42,390) that actually comes pretty well-equipped. Standard features include 17-inch steel wheels, an automatic locking rear differential, xenon headlights, LED running/accent lights, power locks, manual windows, cruise control, a front beach seat, a tilt-only steering wheel, a backup camera, a USB port, an auxiliary audio jack and a 6-speaker sound system. Also standard is a 7-in IntelliLink touchscreen that brings with it Bluetooth and Pandora. There is the choice of cloth or vinyl upholstery.

Next up is the Sierra SLE ($49,090), which adds alloy wheels, rear privacy glass, full power accessories, keyless entry and a remote-locking tailgate, power windows, a leather-wrapped steering wheel, a CD player, HD Radio and an 8-in touchscreen.

Above the SLE is the upscale SLT ($54,190), which adds 18-in wheels, power-folding mirrors, heated 8-way power front seats, driver memory settings, power-adjustable pedals, a tilt-telescopic steering wheel, dual-zone automatic climate control and remote ignition.

To the SLT (4WD/Crew Cab/single rear wheel), you can add the All-Terrain HD package. Available only as a Crew Cab, it adds all-terrain tires, the "Z71" off-road suspension, underbody protection, side steps, a spray-on bedliner, body-color bumper trim, parking sensors and a heated steering wheel. The Z71 suspension can be ordered separately on the SLE and SLT, though again, not with dual rear wheels.

There’s also the popular range-topping Sierra Denali trim ($59,190). Available only as a Crew Cab, it adds unique styling elements, including a new grille design, 20-in wheels, side steps, a power-sliding rear window, parking sensors, ventilated front seats, a heated steering wheel, a navigation system, wireless smartphone charging and a Bose sound system.

In terms of options, the Sierra 2500HD offers quite a few, including upper trim level features being available on lower trims. In addition to the Duramax turbodiesel engine, Sierra buyers can also opt for a heavy-duty trailer package, a snow plow prep package and high-tech safety features, including a forward-collision alert system and a lane-departure warning system that vibrates the driver’s seat should you drift from your lane.


The 2018 Sierra 3500HD boasts standard side airbags, side-curtain airbags, a backup camera, traction control, stability control and trailer sway control. Optional safety features include front and rear park assist, forward-collision alert and a lane-departure warning system.

The 3500HD has not been crash-tested by the federal government’s National Highway Traffic Safety Administration or the Insurance Institute for Highway Safety.

Behind the Wheel

The 2018 GMC Sierra 3500HD is a full-size, heavy-duty truck, and it still drives like one. Expect light steering, huge dimensions that are unfriendly in tight corners and a high seating position. With that said, we’re impressed with the Sierra’s quiet ride, which cancels out wind noise, road noise and even diesel-engine noise better than most full-size trucks.

As for engine choice, the new 6.6-liter turbodiesel is your best choice if you have serious towing and hauling needs — and isn’t that a given for a 3500 truck? Its mammoth 910 lb-ft of torque will pull, pull and keep on pulling no matter what you throw at it. It also benefits from a smart 6-speed transmission, extra cooling for extreme situations and a standard exhaust brake that takes stress off the brakes. When towing, we also appreciate the multiple cameras that aid you when hitching up a trailer and help keep an eye on its sides once under way.

Inside, the Sierra’s cabin design is a little more functional in its design than its competitors’, especially when you compare the popular, range-topping Denali trim to other high-dollar heavy-duty trucks. It has less of an overt luxury feel, but we think that’s okay given its strong quality. We certainly appreciate its no-nonsense functionality, especially its user-friendly IntelliLink touchscreen controls. Climbing into the back, you’ll find abundant room for the family, and there are plenty of creature comforts available to keep everyone comfortable and entertained.

Other Cars to Consider

2018 Chevrolet Silverado 3500HD — The Silverado 3500HD is mechanically identical to the Sierra, and it looks almost the same, too. Check out both pickups, as they’re highly similar, though the upscale Denali trim is unique to the GMC.

2018 Ford F-350 Super Duty — The F-350 Super Duty is all-new for 2017. It gets a stronger frame, more powerful engines, an upgraded cabin and more available features. It’s also available in a wider variety of models and trim levels.

2018 RAM 3500 HD — The heavy-duty RAM 3500 HD is endlessly capable thanks to its huge engines, its wide variety of configurations and unique features, such as a self-leveling suspension and extra-large Mega Cab configuration.

Autotrader’s Advice

We suspect anyone seriously considering the 2018 GMC Sierra 3500 HD over its Chevy cousin wants a little more and is willing to pay for it. In that spirit, we suggest swinging for the fences with the Sierra in Denali trim armed with the Duramax diesel. Not only will it give you bragging rights to the segment’s highest diesel-horsepower rating, but you’ll impress the daylights out of the gang at the country club.

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