2027 GMC Sierra HD

Updated October 2026 by MN, Savvy Dealer Inc.

Heavy-duty trucks have a big job to do, and buyers expect them to handle demanding work without sacrificing comfort or capability. The Sierra HD has long catered to drivers who need more muscle than a light-duty pickup can provide. So, what can buyers expect from this GMC heavy-duty truck? Find out below!

Key Takeaways:

The 2027 GMC Sierra HD costs more across the lineup—diesel models see the largest increase.
With maximum gooseneck towing capacity, the Sierra HD can pull up to 38,000 pounds.
As of October 2026, the Sierra HD will be in our showroom in late 2026.

What's New for the 2027 GMC Sierra HD?

AutoEvolution reports that GMC made several changes to the Sierra HD for 2027, starting with its available engines. The biggest news is an all-new 8.3-liter Duramax diesel, which replaces the previous 6.6-liter diesel. The 6.6-liter gas V8 also gets minor updates with 11 more horsepower and 8 more lb-ft of torque than in the previous model year. Improvements also include a new intake manifold, revised lubrication system, engine-mounted oil cooler, and digital oil-level display, according to GM Authority.

Changes extend beyond the engine. GMC introduces rack-and-pinion electric power steering, an electronic brake-boost system, and larger front brake rotors to the Sierra HD.

How Much Will the 2027 GMC Sierra HD Cost?

Every 2027 Sierra HD trim receives a $900 price increase. The entry-level Sierra 2500 HD Pro now starts at $57,495, and the AT4X starts at $89,195 in crew-cab four-wheel-drive configuration.

Diesel buyers will pay considerably more. The new 8.3-liter Duramax adds $11,400 over the gas V8, making it $1,410 more expensive than the previous diesel option.

That puts the diesel-equipped Pro at $68,895 and the AT4X at $100,595. The diesel-only Denali Ultimate starts at $99,395 before additional options. The AT4X also crosses the $100,000 mark for the first time when equipped with the diesel engine, even before adding optional equipment.

What Engines Are Available in the 2027 Sierra HD?

Buyers have two engine choices: a 6.6-liter gasoline V8 that produces 412 horsepower and 472 lb-ft of torque. The new 8.3-liter Duramax diesel is the more powerful option. GM says it delivers the highest horsepower and torque figures in the heavy-duty truck segment, although we don't yet know its specific output numbers.

How Much Can the 2027 GMC Sierra HD Tow?

With the new Duramax diesel, the 2027 Sierra HD has a max gooseneck towing capacity of 38,000 pounds.

What Does the Sierra HD AT4X Offer for Off-Road Driving?

For 2027, GMC revises its Multimatic DSSV dampers to manage suspension movement under different driving conditions.

The AT4X also gets a new Terrain Mode with one-pedal driving, letting the driver better control low-speed movement with the accelerator and reducing the need to switch constantly between it and the brake when navigating obstacles.

Find Your GMC Sierra HD Model

Ready to see what the 202 Sierra HD can do for you? Our Reliable dealership can help you explore the lineup, compare available models, and find the truck that matches your needs (and, of course, your budget). Contact us to learn more about its arrival and schedule a visit when it arrives!