2025 GMC Sierra 3500 HD Crew Cab

As appropriate pulling up to the valet stand at a 5-star restaurant as it is hauling bricks to the job site or pulling a boat to the lake, the 2025 GMC Sierra HD is a workhorse, doubling as a show pony for date night and family outings. Capable of tugging up to 36,000 pounds when properly outfitted, it doesn’t shy away from the tough jobs but can be downright luxurious in its Denali and Denali Ultimate trims.

We’ve spent hundreds of hours driving and evaluating this generation of full-size heavy-duty trucks, including the GMC Sierra HD.

Enjoying a major refresh for 2024, the Sierra HD rolls into the new model year with minor upgrades. Of note is the migration downward of its adaptive cruise control with trailering assist from the AT4X and Denali Ultimate trims to the AT4 and Denali grades. All trims now provide the trailer-brake controller as standard. As another nod to safety, the entry-level Pro and next-in-line SLE grades can now add front and rear park assist.

Although as the Sierra HD and its key rivals, the Ford Super Duty, the Ram HD variants, and the Sierra’s corporate cousin, the Chevy Silverado HD, age, their prices on the used market may (and do) deviate, they are all in the same ballpark when new. The 4-wheel-drive Sierra 2500 HD Denali with the Duramax diesel engine is a very popular option. If you like the cut of the Sierra HD’s jib but want to spend a bit less, we will direct you to the Chevy Silverado HD. If you want to spend a lot less and don’t require the towing and payload capabilities of the Sierra HD, you will save yourself some money and stress during inner-city parking by picking the 1/2-ton Sierra 1500 instead.

Before buying a Sierra HD, check the Kelley Blue Book Fair Purchase Price to know what you should really pay. The Sierra 2500 holds its value better than the rest of the ¾-ton competition; however, the Sierra 3500 doesn’t do as well as the Ford F-350 or Ram 3500 five years down the road. Of course, that means it’s a better deal on the used market.

Despite its engorged dimensions, the GMC Sierra HD still drives like an overgrown pickup truck. Therefore, we found it comfortable and composed for its considerable size. Rough roads are no problem for the Sierra HD, and it floats along rather nicely on the highway.

Since GMC engineered this truck expressly for heavy towing and hauling, it tugs without skipping a beat as long as your load is within its capabilities. We found that it pulls especially comfortably when propelled by the available Duramax turbodiesel V8, making well over 900 lb-ft of torque. The standard gas V8 gets the job done but strains a bit in the heaviest towing situations.

As for off-road capabilities, the rugged AT4 and AT4X models are the most adventurous variants in the Sierra HD lineup. Separating the AT4 and AT4X goes beyond the $11,000 price difference. The AT4 has Rancho shocks and all-terrain tires, while the AT4X boasts 35-inch tires, stronger skid plates, and more robust suspension components, including Multimatic DSSV shocks.

Fuel Economy

The government doesn’t keep track of nor publish fuel-economy estimates for this pickup classification.

To say that the GMC Sierra HD is somewhat more premium than the average heavy-duty truck is at least somewhat understating the facts. The interior design is upscale yet practical. Every Sierra HD has roomy front seats. We found the legroom adequate when we climbed in the back of the Double Cab. However, we’d much prefer the Crew Cab’s rear seats on a long road trip. The Crew Cab also benefits from under-seat storage. For context, the rear seat in the Sierra HD Crew Cab is about the same as the Ford Super Duty Crew Cab and roughly 3.0 inches more than the Ram HD.

The Sierra HD becomes more impressive inside as you travel along the model range. For example, the SLT and higher trims come with perforated leather seats, the AT4 trim has Jet Black and Kalahari interior accents, and the Denali model is full of luxurious materials like Denali-exclusive leather and open-pore wood trim.

The top Denali Ultimate grade is one of the most luxurious trucks in this class. It boasts premium features like massaging front seats, a microsuede headliner, and a Bose 12-speaker audio system. It rivals the Ford Super Duty Limited and Ram HD Limited.

The GMC Sierra HD straddles a thin line, balancing a look that is both premium and rugged. The GMC design language is fully displayed, but it still looks unique compared to the smaller Sierra 1500 and the mechanically similar Chevrolet Silverado HD.

The Sierra HD’s exterior changes a bit with each trim, as does its interior. The AT4 models have rugged appearance packages with red tow hooks and stylish black accents. The Denali grade has a flashy grille and wheels. The Denali Ultimate model adds a unique look with Vader chrome exterior trim, 20-inch wheels, power running boards with LED lighting, and a Kicker audio system within the MultiPro tailgate.

One of our favorite exterior features of the Sierra HD is the 6-position MultiPro tailgate. You can configure it with load stops, cab steps, a “Work Surface” desk, and more.

Where we do find some commonality is how its size compares to the other entries in the heavy-duty segment, like the Chevrolet Silverado HD, Ram HD, and Ford Super Duty. As with every truck in this class, it offers numerous configurations with three cab sizes, two bed lengths, and even a chassis cab option.

Another characteristic this class shares is the issue of driving and parking in crowded city spaces. Where the sheer size of an HD truck enhances its ability to tow and haul immense weight, it also means more hassle when dealing with busy city streets and narrow parking spaces. Hey, it’s a trade-off.

Luxurious Denali Trim
The Sierra HD Denali is a luxury pickup truck that doesn’t skimp on capability. It has a premium appearance package, perforated leather seats (heated and cooled in front), open-pore wood trim, a Bose premium sound system, and much more. To kick it up another notch, opt for the even more opulent Denali Ultimate grade.

Off-Road-Ready AT4 Models
The AT4 and AT4X models are capable off-roaders. On top of a rugged appearance package inside and out, they come with skid plates, an off-road inclinometer, all-terrain tires, and upgraded suspension systems. We’ve spent time in the AT4 and the even more capable AT4X. Both are highly competent when the pavement expires.

Duramax Turbodiesel V8
This optional turbodiesel V8 vastly increases the torque rating and towing capability of the Sierra HD. When properly equipped, it can tow a whopping 36,000 pounds, plus it’s likely more fuel-efficient than the base engine. (The EPA doesn’t require fuel economy ratings for these big trucks.) If hard work is high on the list of your pickup needs, we say, go with the Duramax.

MultiPro Tailgate
The MultiPro tailgate is standard on all but the base Pro trim of the Sierra HD. It has six different positions, including load stops, cab steps, a desk, and more. We were skeptical before we actually sampled this versatile accessory. Now, it would be high on our list of reasons if we were buying a Sierra HD.

ProGrade Trailering System
The ProGrade Trailering System includes Hitch Guidance with Hitch View, GCW (Gross Combined Weight) Alert, Bed View, and more, making towing and hauling safer and easier. It also has an in-vehicle trailering app. We think this is some of the best towing tech in the industry.

Wireless Android Auto and Apple CarPlay
We appreciate the convenience of this standard feature, bringing your maps, music, and more to your Sierra HD’s infotainment touchscreen (13.4-inch on SLE and higher trims) without removing your phone from your pocket.

The 2025 GMC Sierra HD lineup includes a choice of two V8 engines: strong and stronger.

The Sierra HD’s base engine is a gas-powered 401-horsepower (hp) 6.6-liter V8 that makes 464 lb-ft of torque and mates to a 10-speed automatic transmission. Sufficient for most HD pickup drivers, it’s a robust engine optimized for towing and hauling. This mill is similar in horsepower to the base engine in the Ford Super Duty or the Ram HD and has the most torque of the three. If you don’t have the budget or the need for the diesel, the gas V8 is plenty.

The available 470-hp Duramax turbodiesel V8 significantly boosts the torque rating (975 lb-ft) and maximum towing capability (36,000 pounds) of the Sierra HD. Ford’s answer to the Duramax is a 500-hp 6.7-liter turbocharged High Output (HO) Power Stroke V8 that generates 1,200 lb-ft of torque. It can tow up to 38,000 pounds in the F-350, while the Ram 3500 can tug up to 37,090 pounds with the 1,075 lb-ft of torque generated by its available 6.7-liter HO turbodiesel.

3-Year/36,000-Mile Warranty

GMC backs the Sierra HD with a 3-year/36,000-mile basic warranty and a 5-year/60,000-mile powertrain warranty. This coverage is average for this segment. You also get one complimentary service visit for an oil change, tire rotation, and multipoint inspection.

Safety

Most advanced safety tech is available on the options list or as standard as you move up through the trim levels. Such upgrades include a surround-view camera, blind-spot monitoring with trailer assist, rear cross-traffic alert with automatic emergency rear braking, and more.