2027 GMC Sierra HD in Newport, Arkansas

Updated October 9, 2026, from GM's September 24 heavy-duty truck release and gmc.com's 2027 Sierra HD preview page. Engine ratings are GM's, under SAE J1349.

What's new for the 2027 Sierra HD

• Duramax 8.3L turbo-diesel V8: 555 hp and 1,230 lb-ft, available on the Sierra HD and standard on the Denali Ultimate.
• Steering and brakes: electric power steering replaces hydraulic, and electronic brake boost arrives with larger brakes.
• AT4X: a 1.5-in. lift, larger Multimatic DSSV dampers, a rear electronic locker, 35-in. mud-terrain tires and a new one-pedal Terrain Mode.
• Enhanced 6.6L gas V8: the standard engine, rated at 412 hp and 472 lb-ft.

2027 Sierra HD trims

GMC's 2027 Sierra HD page lists Pro, SLE, SLT, AT4, AT4X, Denali and Denali Ultimate, with the AT4X not offered on the 3500HD.Unlike the 2027 Sierra 1500, the HD keeps the SLE and SLT names on that list.

Engines and towing

The standard 6.6L gas V8 makes 412 hp and 472 lb-ft, and the available 8.3L Duramax makes 555 hp and 1,230 lb-ft. Both use an Allison 10-speed automatic.

• Sierra 3500HD: up to 38,000 lb of gooseneck towing in a Regular Cab long bed 2WD dually with the 8.3L, the Max Trailering Package and a gooseneck hitch.
• Sierra 2500HD: up to 23,100 lb in a Regular Cab 2WD with the 8.3L, the Max Trailering Package and a gooseneck hitch.
• Across the HD line: up to 20,000 lb of conventional towing and up to 46,500 lb GCWR when properly equipped.

These are maximums for specific configurations. Ask us to look up the rating for the cab, bed, axle and hitch you plan to buy.

Trailering technology

GMC lists its ProGrade Trailering system and up to 14 camera views, including Transparent Trailer View.

When the 2027 Sierra HD arrives

GM says the 2027 Sierra HD reaches U.S. dealers beginning late 2026. Call us for the latest on timing and on how to order the configuration you want.

Shopping a 2027 Sierra HD at George Kell GMC

Start with how much you tow and how: bumper pull, fifth-wheel or gooseneck. That decides 2500HD or 3500HD, single or dual rear wheels, and gas or diesel. Then check what's on our lot today and what makes sense to order.

See new Sierra HD inventory → · Call sales: 870-523-2792 · Finance application →

For a used heavy-duty pickup, browse George Kell GMC used inventory.

Duramax service, tires and accessories after you buy

The shared Chevrolet and GMC service department at 3808 South Van Dyke Road handles Duramax diesel service; read our diesel truck service guide before your first visit. Schedule GMC service online or call for current hours, and ask about free service pickup and delivery within 50 miles.

For load-rated tires and the AT4X's 35-in. mud-terrains, start with our tire guide. Steps, bed equipment and wheels are on the truck accessories page, and towing and vehicle transport covers trucks that can't be driven.

Northeast Arkansas shoppers

Hay season, cattle sales and camper trips put very different loads on a heavy-duty truck. If you're driving in from Batesville, Searcy, Swifton or Jonesboro, call ahead with the trailer you pull most so we can have the right Sierra HD ready to compare.