• General Motors has revealed a significantly refreshed Chevrolet Silverado HD and GMC Sierra HD for the 2027 model year.
  • The heavy-duty trucks get new engines, including a diesel 8.3-liter V-8 with 1,230 pound-feet of torque, and they adopt an electric rack-and-pinion setup.
  • The new HD trucks are expected to go on sale by the end of the year, with prices to be announced before then.

When looking at the refreshed versions of the heavy-duty Chevrolet Silverado and GMC Sierra, we can’t help but think of the Fiat S76. Built in 1910, the S76 is better known as “The Beast of Turin.” It earned that moniker because of its 28.3-liter four-cylinder engine that sounds like a chained eldritch beast. These new GM workhorses, many of which will be powered by the company’s new diesel 8.3-liter V-8, could use a nickname as well. We haven’t heard the new engine — officially called Mongoose — roar yet, but maybe “Devil of Detroit” will work.

A blue pickup truck towing an off-road vehicle trailer on a dirt road surrounded by mountains and greenery.

Engines and Powertrain

The new massive-displacement Duramax diesel will serve as an optional engine on both the Silverado HD and Sierra HD. As the new flagship engine, the Mongoose produces 555 horsepower and 1,230 pound-feet of torque. It’ll be joined by an updated gas-burning 6.6-liter V-8, which now generates 412 horsepower and 472 pound-feet of torque. The gasser benefits from a new turbo-jet intake manifold that GM tuned specifically for HD performance. This powertrain also receives better cooling and lubrication under load, which is helpful since these HD pickups are often towing something. Both engine options are connected to an Allison 10-speed automatic transmission.

Towing Capacity

The power increases come with meaningful gains in towing capacity. The HD’s maximums have risen to 20,000 pounds with a conventional trailer hitch, while models equipped with a gooseneck setup can now haul up to 38,000 pounds. Every diesel truck configured with a dual-rear-axle setup can now tow at least 30,000 pounds. The 2500 maxes out at 23,200 pounds, though opting for the crew cab drops that figure to 22,400 pounds.

Dark green pickup truck parked on rocky terrain with blue sky and distant mountains in the background.

Steering and Brakes

The new trucks should also feel better behind the wheel. GM has finally ditched the old recirculating-ball steering found on every other heavy-duty truck and switched to an electrically assisted rack-and-pinion setup. Not only does the new system have about 30 percent more power than the outgoing hydraulic setup, according to GM, but it should offer much more precise steering. The first-in-the-segment steering is joined by a first-in-the-segment electronic brake-boost system.

The new GM trucks also come with 14.6-inch front rotors, four-piston front calipers, and updated hardware for the rear brakes. The new brakes can take more heat and — coupled with a new pedal placement and more linear brake travel — should improve confidence while hauling heavy loads.

Availability and Pricing

GM says the 2027 Chevy Silverado HD and 2027 GMC Sierra HD are expected to arrive by the end of the year. Pricing has not yet been announced, but given how close the new model year is, those figures should follow soon.