2020 GMC Sierra Heavy Duty Is Their ‘Most Capable’ Truck Ever

First photos and specs of GMC’s musclebound new truck.

gmc sierra heavy duty truck

GMC’s latest Sierra Heavy Duty is here, and it’s already being called the company’s “most capable” truck ever. 

The 2020 Sierra HD still runs a 445-horsepower, 6.6-liter Duramax turbodiesel V8. But the high-end pickup now has a brand new Allison 10-speed automatic transmission to handle all 910 pound-feet of torque. 

The 2020 GMC Sierra 3500 HD. 

This improved powertrain translates to a towing capacity that GMC says is “well in excess of 30,000 pounds”—official figures have yet to be released.


With a slightly smaller engine, the Sierra HD will probably approach—but not surpass—the performance of the 1000-pound-feet club’s first member: the 2019 RAM HD. But there are other impressive features that might pull truck-lovers over to camp GMC.

The 2020 GMC Sierra 3500 HD. 

The new triple-tiered grille, complementary hood scoop and chrome accents look undeniably badass. It also has a 15-angle camera configuration that allows drivers to “see through” trailing cargo.

Then there’s the nifty “MutliPro” tailgate. The Drive has further details: 

For the 2020 Sierra HD, the admittedly-clever piece of kit will be standard on SLT trucks and above and optional on lower trims.

More important to daily users might be the one-inch-lower bed floor that makes load-in and fifth-wheel hitching just a little easier and standard side steps in front of the rear wheels to improve bed access all around.

The 2020 GMC Sierra 3500 HD

Two trim options will be offered. One is the expected “Denali” package, which upgrades the interior with premium leather-appointed seating, authentic open-pore wood and dark-finish aluminum decor. 

The 2020 GMC Sierra 2500 HD Denali. 

But the new off-road spec “AT4” trim goes beyond the cabin, with Rancho shocks, skid plates, and 18-inch (or available 20-inch) wheels, plus an “Off-Road” driving mode and inclinometer.  

The 2020 GMC Sierra 2500 HD AT4. 

The 2020 Sierra HD’s price has yet to be announced, but those details will come when it hits dealerships this summer.