2021 GMC Sierra 3500 HD

The 2021 GMC Sierra 3500 HD comes in five trims: base, SLE, SLT, AT4, and Denali. Just like with most other trucks on the market, this truck has plenty of cab and bed options.

The regular cab models, which have either two or three seats, come with an 8-foot-2-inch bed along with 83.5 cubic feet of cargo volume. The double-cab variants, which have seating for five or six travelers, come with either a standard 6-foot-9-inch bed with 69.9 cubic feet or the 8-foot bed. The crew cab has a spacious interior while also offering the double cab's two bed options.

You'll find one of two engine options under the hood of the 2021 GMC Sierra 3500 HD, with one gas and the other diesel. The gasoline-powered 6.6-liter V-8 engine produces 401 horsepower and 464 pound-feet of torque. It comes standard with a six-speed automatic transmission and rear-wheel drive, but all-wheel drive is optional. For additional power, consider the 6.6-liter V-8 diesel engine that generates 445 horsepower and a massive 910 pound-feet of torque. It comes mated to a 10-speed automatic transmission and rear-wheel drive.

When properly outfitted with the Max Tow package, the diesel engine, and the dual-rear-wheel configuration, the 2021 GMC Sierra 3500 HD can tow a maximum of 36,000 pounds. It also has a maximum payload capacity of 6,610 pounds.

Once you step inside the 2021 GMC Sierra 3500 HD, you'll notice the user-friendly technology features. It comes standard with Apple CarPlay and Android Auto connectivity along with a 7-inch touch-screen display. The upper trims have a larger 8-inch display.

Selecting the SLT trim or higher, you gain satellite radio and voice control. The Denali models include integrated navigation. The base model has a 3.5-inch display located in the instrument cluster, and the higher trims have either a 4.2- or 8.0-inch display. Many of the trims include a six-speaker stereo system, but the Denali comes with a seven-speaker Bose system.

If you're looking for extensive driver-assistance safety features, most modern technology options are available as add-ons. Some of these features include blind-spot monitoring, automatic emergency braking with forward-collision alert, rear cross-traffic alert, and a 360-degree camera. The truck has a rear camera mirror, which is a feature not found on other heavy-duty pickup trucks. Once you flip a switch, the rearview mirror becomes a video screen, projecting a wide-angle view of what's behind you.

Also, the truck now has an abundance of trailer features found in the ProGrade Trailering System, which can help you navigate the roads better when towing a trailer. You gain a trailer-length indicator, jack-knife alert, trailer-angle indicator, rear trailer-view guidelines, and rear side-view enhancement.