Search Cars for Sale

2015 GMC Sierra 3500HD: New Car Review

Editor’s note: If you’re looking for information on a newer GMC Sierra 3500HD, we’ve published an updated review: 2018 GMC Sierra 3500HD Review.


The heavy-duty GMC Sierra is one of the most capable and massive pickup trucks you can buy today. Designed not for city streets but rather commercial-grade applications such as towing, hauling and getting around dusty jobsites, the Sierra is a true work truck, and the 3500 model is at the top of the heap.

As for the 2015 GMC Sierra 3500HD, it’s been redesigned for the latest model year. But while its styling is modernized, its ride is improved, and its cabin materials are a cut above last year’s heavy-duty Sierra, don’t let the changes fool you: The truck is still the same competent, highly capable workhorse that it’s always been. See the 2015 GMC Sierra 3500HD models for sale near you

What’s New for 2015?

The GMC Sierra 3500HD is fully redesigned for the 2015 model year. While it keeps last year’s engines, the latest Sierra boasts new styling, a revised interior, new equipment and a new double-cab model that replaces last year’s extended cab. 

What We Like

Impressive towing and hauling capabilities; huge power and torque from any engine; new interior is a major improvement

What We Don’t

Manual transmission would be nice; pricing a little steep; no self-leveling suspension like RAM HD

How Much?


Fuel Economy

The 2015 GMC Sierra 3500HD offers two engines, both of which are carried over from the 2014 model. The truck’s standard powerplant is a 6.0-liter V8 that makes 360 horsepower and a muscular 380 lb-ft. For drivers who want more power, the truck also offers a 6.6-liter turbodiesel V8, which makes 397 horses and an impressive 765 lb-ft of torque.

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 the trucks aren’t for buyers interested in saving fuel. Most drivers will see around 12 miles per gallon in the city and 17 mpg on the highway, regardless of engine choice.

Standard Features & Options

The Sierra 3500HD comes in a wide variety of trim levels, body styles and configurations. There are regular cabs and crew cabs, and for the 2015 model year, there’s now an extended cab model with four full doors. There are 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.

When it comes to trim levels, the Sierra 3500HD offers four: a base-level Sierra model, mid-level SLE and SLT trims, and an upscale luxury-oriented Sierra Denali.

Choose the Sierra ($34,200) and you’ll get only the basics, as this trim level is primarily designed for use on gritty jobsites. Standard features include an AM/FM stereo with an auxiliary port (but no CD player), air conditioning, vinyl seating and little else. In fact, these Sierra 3500HD models don’t even include features such as keyless entry or power mirrors.

Next up is the SLE ($37,800), which adds many missing creature comforts as standard equipment. There are heated mirrors, for instance, and remote keyless entry. There’s GM’s OnStar telematics system, which can provide directions and other assistance. And there’s a standard backup camera, which is helpful in a truck this large.

Slotting above the SLE is the SLT ($46,200), which offers all the luxury that most shoppers will ever need. There’s leather upholstery, dual-zone automatic climate control, chrome door handles, LED lighting and heated front seats. SLT models also offer available front and rear park assist.

Topping the Sierra HD’s range is the Denali ($51,700), which adds a long list of high-end equipment. Features include a heated steering wheel, cooled front seats, additional chrome accents, a vastly improved interior with contrasting stitching and aluminum trim, and a navigation system.

In addition to the Sierra 3500HD’s standard features, the truck also offers quite a few options. Of course, there’s the 6.6-liter Duramax turbodiesel engine for shoppers interested in more power and torque, but the truck also offers a heavy-duty trailer package, 4-wheel drive, power adjustable pedals, and front and rear park assist. Shoppers can also add high-end safety features such as a lane-departure warning system and forward-collision alert.


The 2015 Sierra 3500HD boasts plenty of standard safety equipment, such as side airbags, curtain-side airbags, traction control, stability control and daytime running lights. Also standard is a trailer sway control feature, which helps to stop trailers from swaying. Optional safety features include a backup camera, front and rear park assist, forward-collision alert and a lane-departure warning system.

Because of the 3500HD’s recent redesign, the pickup has not yet been crash-tested by the federal government’s National Highway Traffic Safety Administration or the Insurance Institute for Highway Safety.

Behind the Wheel

The GMC Sierra 3500HD is a full-size, heavy-duty truck, and in spite of changes for the 2015 model year, it still drives like one. Expect light steering, huge dimensions that are unfriendly to 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.

Step inside the Sierra 3500HD and we suspect you’ll be impressed with the truck’s modern new dashboard and center stack. Both items are unusual in the world of the heavy-duty truck, where cutting-edge features and new equipment are rarely added. We’re also impressed with the truck’s rear-seat room, especially in crew-cab models. Still, we wouldn’t suggest using any Sierra 3500HD as around-town family transportation, given its massive size and inevitable parking difficulties.

Other Cars to Consider

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.

RAM 3500HD — The heavy-duty RAM 3500HD is endlessly capable thanks to its huge engines, its wide variety of configurations, and unique features such as self-leveling suspension and a manual transmission. But the latest Sierra is far more refined than the RAM.

Ford F-350 — The increasingly outdated F-350 isn’t as refined as rivals such as the RAM, the Sierra and the Silverado, but with a new model on the way, it may be a better deal.

Autotrader’s Advice

Because there are so many versions of the Sierra 3500HD, recommending the right one is a difficult task. In the end, we like the pickup, and we think you’ll need to carefully consider the model lineup to decide which one is the best for you. If you’re looking for a family hauler, it’ll be the crew cab. Want to tow a trailer? Go for the turbodiesel. No matter what your desire, truck shoppers will find something for just about everyone in the Sierra 3500HD. Find a GMC Sierra 3500HD for sale


Sign up for Autotrader newsletters

The best cars and best deals delivered to your inbox

Email Address 

By subscribing, you agree to our privacy policy

Where You Can Buy

Loading dealers...

Leave a Comment

Most Popular Articles

2020 Hyundai Sonata Hybrid: First Look

The 2020 Hyundai Sonata Hybrid jumps to the head of the hybrid class.

Best Truck Deals: July 2021

These are the best deals on trucks for the month of June.

Search By Style

More Articles Like This