2026 GMC Sierra HD: Specs, Towing, and More

The standard-issue GMC Sierra 1500 is an absolute beast, but sometimes, a half-ton pickup just doesn’t cut it. For the days that demand more of your truck, the Sierra 2500 HD and Sierra 3500 HD offer class-leading performance to tackle the heaviest loads and the toughest jobs without breaking a sweat. 

Read on to find out just how powerful a truck can be when you shop at our GMC dealership near Dentsville, SC. 

  

2026 GMC Sierra HD Trims 

The Sierra HD has a broad variety of trims, from the affordable and no-frills Pro to the off-road conquering AT4X and ultra-luxury Denali Ultimate. Here’s the complete lineup, along with their starting prices: 

• Pro: $47,000 

• SLE: $54,000 

• SLT: $65,200 

• AT4: $72,200 

• Denali: $75,200 

• AT4X: $85,200 

• Denali Ultimate: $94,200 

2026 GMC Sierra HD Engines 

The Sierra HD dominates with two burly engine options, including one gas-powered and one diesel. The standard 6.6-liter V8 engine cranks out 401 horsepower and 464 pound-feet of torque, while the almighty Duramax™ 6.6-liter Turbo Diesel creates 470 horsepower and 975 pound-feet of torque, unlocking the maximum towing capacity (more on that in a minute). 

Both engines are paired with a durable 10-speed Allison® transmission, and they can be optioned with your choice of rear-wheel drive or four-wheel drive.

2026 GMC Sierra HD Dimensions 

With three cab sizes and two bed lengths, the Sierra HD can be configured in multiple different ways based on your specific needs. Here’s a look at all the combinations available: 

• Regular Cab, Long Bed 

• Double Cab, Standard Bed (2500 HD only) 

• Double Cab, Long Bed 

• Crew Cab, Standard Bed 

• Crew Cab, Long Bed 

Here’s a comparison of its cab and bed dimensions: 

2026 GMC Sierra HD Cab Sizes
	Regular Cab	Double Cab	Crew Cab
Max passenger capacity	3	6	6
Head room (front/rear)	43.11 / —	43.11 / 39.88 in	43.11 / 40.12 in
Shoulder room (front/rear)	66.06 / —	66.06 / 64.88 in	66.06 / 65.30 in
Leg room (front/rear)	44.53 / —	44.53 / 35.24 in	44.53 / 43.40 in

  

2026 GMC Sierra HD Bed Lengths
	Standard Bed	Long Bed
Length	82.20 in	98.27 in
Width	71.40 in	71.40 in
Height	21.00 in	21.00 in
Total volume	69.50 cu ft	83.50 cu ft

  

One more thing to consider: only the Sierra 3500 HD with the Long Bed can be optioned with Dual Rear Wheels, which massively increase towing capacity and payload. 

2026 GMC Sierra HD Towing Capacity and Payload 

The 2026 Sierra 2500 HD has a max towing capacity of 22,390 pounds, while the 2026 Sierra 3500 HD has a max towing capacity of 36,000 pounds when fitted with a dual rear wheel axle. 

However, your truck’s trailering capacity and payload depends on a number of factors, including the engine, drive type, cab and bed style, and available trailering packages. For instance, in order to tow the 3500 HD’s maximum 36,000 pounds, GMC recommends that you’ll need to configure it like this: 

• Duramax™ Turbo Diesel 

• 4WD 

• Regular Cab 

• Long Bed 

• Dual Rear Wheels 

• Max Trailering Package 

• Gooseneck hitch 

• Convenience Package 

Changing or omitting any of these elements will have an effect on towing and payload specs, so it’s essential to find the right rig for your needs. Luckily, it isn’t as intimidating as it sounds—you can find specific trailering information on the sticker in the driver’s side doorjamb, or you can contact your local truck and towing experts at Jim Hudson Buick GMC and we’ll be happy to guide you to the perfect model. 

2026 GMC Sierra HD Exterior 

The Sierra HD has a number of standard and available features to bolster performance and enhance appearance. Aside from the trim-specific features like unique wheels and exterior accents, all models come with LED daytime running lights, vertical trailering mirrors, and at least 12 in-bed cargo tie-downs rated for 500 pounds each. 

A stand-out feature on the GMC Sierra HD is the six-way adjustable GMC MultiPro Tailgate, which makes loading, unloading, and accessing the bed far easier. This class-topping feature is available across all trim levels, allowing you to build the perfect work truck at any price point. 

Other available features include: 

• Up to 14 exterior camera views 

• Factory-installed 1.5-inch suspension lift 

• Rear electronic-locking differential 

• Upgraded suspension components 

• AEV® stamped steel front and rear bumpers 

• Underbody skid plate protection 

• Power-retractable assist steps with LED lighting 

• MultiPro™ Audio System by Kicker 

2026 GMC Sierra HD Interior 

Front and center in nearly all trims except the base-level Pro, we find a 12.3-inch driver info display and a giant 13.4-inch center touch screen with Google built-in, Bluetooth, Apple CarPlay®, Android Auto™, and Wi-Fi hotspot capability, offering a variety of connectivity options and ways to interact with media and navigation. Every model also comes with the GMC Pro Safety package, which includes driver assistance features like Forward Collision Alert, Automatic Emergency Braking, Front Pedestrian Braking, Lane Departure Warning, and more 

Other available tech and comfort features for a truly premium experience include: 

• Remote Start 

• Multiple upfitter switches 

• Dual-zone climate control 

• Heated steering wheel 

• Heated and ventilated seats 

• Bose Premium Series with 12-speaker system with CenterPoint 

• Wireless phone charging 

• 15-inch head-up display 

• HD Surround Vision 

• Rear camera mirror 

Frequently Asked Questions 

Does the 2026 GMC Sierra HD have Super Cruise? 

No. Contrary to what some dealerships currently claim, GMC does not currently offer Super Cruise for any Sierra HD models or trims. However, there are rumors circulating about them including it in the next generation of Sierra HD models. 

What is the difference between the Sierra 2500 and 3500? 

Both have many similarities, but the main difference is that the 3500 has more robust body-on-frame construction and suspension, as well as an available dual rear wheel axle, which gives it a higher maximum towing and payload rating. 

Does the GMC Sierra 2500 HD have a short bed option? 

Unlike the Classic Sierra 1500, Sierra HD models can only be optioned with a Standard Bed or Long Bed. 

  

Find New GMC Sierra HD Models in Columbia, SC 

At Jim Hudson Buick GMC, we have an excellent selection of new Sierra HD models, with a variety of trims, powertrains, and body styles to suit the needs of any shopper. Whether you’re looking for a brawny work vehicle or buying your dream truck to tow all of your toys, we have you covered. 

Call us today at (803) 462-4475 to schedule a test drive—and don’t forget to check our new vehicle specials to find our latest GMC truck lease deals and finance offers.