A black 2021 GMC Sierra 3500 HD is parked in a field.

Brawny but Comfortable: The 2021 GMC Sierra 3500

Most truck drivers are accustomed to having a choice. That is, a choice between a truck that can handle heavy jobs and a truck that’s enjoyable to drive. The GMC Sierra rejects this either/or notion, providing drivers with a selection of trims that will make daily driving of a Heavy Duty(HD) pickup truck feel less like a chore and more like a privilege. The 2021 GMC Sierra 3500 has a bunch of “Best in Class” accolades to its name, but it’s hardly the plastic seat, crank window, no radio type of heavy duty truck that drivers had no choice but to drive just a few decades ago.

Instead, the full range of options and configurations allow drivers to custom-tailor their on-the-road experience, and in the case of the GMC Sierra 3500 AT4 trim, that also includes off-road adventures, as well. It takes a special driver to pilot a heavy-duty truck, but it takes an even more special truck to make drivers want to drive it. From standard safety features to optional trailering aids that improve your work capability, the 2021 GMC Sierra 3500 is designed to be a truck for drivers and workers.

Under the Hood of the 2021 GMC Sierra 3500

In order to haul massive loads and faithfully carry a work crew to the site each and every day, a heavy-duty truck needs an equally well-prepared engine. The 2021 GMC Sierra 3500 comes with a choice of two 6.6L V8 engines.

The first option is the gasoline version of this engine. Equipped with direct fuel injection technology, this DOHC engine provides 401 horsepower and 464 lb-ft of torque at the driver’s command. This engine is paired to a nimble and responsive six-speed automatic transmission, taking all the guesswork out of the gears. The second 6.6L V8 engine is a Duramax turbo diesel option. This engine takes the power up to the next level, with 445 horsepower and 910 lb-ft of torque. Paired to an Allison ten-speed transmission, this engine is prepared for whatever antics drivers might need to throw its way.

Early test drives of the 2021 GMC Sierra indicate that the 3500 model is smooth and highly drivable with either engine option. Those who are looking for the most versatile power source may lean towards the turbo diesel engine, as it can not only tow best-in-class loads but has the ability to speed from 0 to 60 miles per hour in 19.9 seconds while pulling a trailer rated at 18,000 pounds. However, the regular gas engine still performs excellently.

The interior of a 2021 GMC Sierra 3500 shows the steering wheel and infotainment screen.

2021 GMC Sierra 3500 Capability and Configurations

Like any other pickup truck, HD or not, the 2021 GMC Sierra 3500 is offered in several cab/bed configurations. Each version excels in various areas. The best-in-class towing maximum of 36,000 pounds, for example, is achieved when drivers choose the Regular Cab with the Long Bed and dual rear wheel setup with rear-wheel drive. This maximum also requires the available Duramax 6.6L turbo diesel V8 engine and the Max Trailering Package with a gooseneck hitch. At first glance, that might sound like a lot of qualifications, but the turbodiesel is a natural choice for anyone who will be pulling heavy loads, and the Regular Cab is always paired with the Long Bed.

The 3500 is offered as a Crew Cab with a Standard Bed, which measures 6.8 feet, or the Long Bed, which is 8.2 feet. Double Cabs are offered with Long Beds only, like the Regular Cab option. All Long Beds have the choice of the single or dual-rear-wheel, as well. The AT4 and Denali trims are offered as four-wheel drive only, but all other trims and cab/box configurations may be had in rear-wheel drive or four-wheel drive.

The towing and payload ratings vary based on configuration. A single-rear-wheel Double Cab/Long Bed version can handle a payload of up to 4,148 pounds, while a dual-rear-wheel version of the same truck with rear-wheel drive can handle up to 6,059 pounds of payload. Conventional hitch limits hover around 20,000 pounds for most models, with fifth-wheel ratings at a maximum of 21,500 pounds. With a GCWR of 40,000 pounds plus, the dually versions have the highest fifth-wheel and gooseneck towing capacity, with all configurations pulling over 31,000 pounds.

Trims and Options for the 2021 GMC Sierra 3500

The 2021 GMC Sierra 3500 is offered in five trims, each of which presents a distinct personality to the driver. The base Sierra, for example, includes the gasoline engine, two USB ports, low maintenance flooring, air conditioning, LED headlamps, and connectivity with Apple CarPlay and Android Auto, making it a perfectly suitable road companion. However, stepping up a bit to the SLE trim adds carpet, cruise control, WiFi, OnStar, and a leather-wrapped steering wheel. You’ll also get GMC’s MultiPro Tailgate, which drops into a variety of configurations to make it a versatile surface for measuring, cutting, hauling, using tools, or even eating a quick lunch.

The SLT trim provides an abundance of creature comforts, like heated and power adjustable front seats and steering wheel, wireless connectivity, and dual-zone automatic climate control. There is also a host of convenience features that any driver can appreciate, such as perimeter lighting, a self-dimming rearview mirror, and a high-definition rear view camera. The AT4 is prepared for adventures on and off the beaten track, with skid plates, off-road-tuned suspension with Rancho shocks, heated and ventilated bucket seats featuring leather upholstery, and a two-speed transfer case with its standard four-wheel drive. At the top of the trims is the Denali. It stands high above the other trims on 20-inch wheels and includes standard trailer cameras, high definition 360-degree camera view, Bose sound system, and wireless charging capability.

The 2021 GMC Sierra 3500 offers drivers plenty of available options to increase safety for drivers, trailers, and more. The In-Vehicle Trailering App connects to the infotainment system and provides drivers with real-time trailer tire pressure readings, light sequence testing, temperature monitoring, and more. Jackknife Alert keeps track of the angle of the trailer and vehicle and provides a yellow warning when the angle is heading towards a jackknife. If the trailer is 90% into a jackknife, this alert turns red.

Up to 15 camera views are available, which is another class-leading statistic for the Sierra 3500. The transparent trailer view is an industry first, which provides drivers with a view of the rear surroundings as if the trailer weren’t there. An available Head-Up Display is also helpful, providing a 15” diagonal projection of essential vehicle information right onto the windshield. Settings include speed, phone and audio controls, and navigation, as well as helpful alerts like Forward Collision and Lane Departure Warnings.

A black 2021 GMC Sierra 3500 is towing a camper down an open road with mountains in the back.

Though It Is Large, It Is Still Comfortable

The 2021 GMC Sierra 3500 may be a very large HD truck, but it’s designed with the drivers in mind. From comfortable seats with ample leg and headroom to add-on packages that make driving a behemoth vehicle simpler and safer to drive, GMC has considered the needs of the driver beyond the basics of a best-in-class towing maximum and payload limits. While a work truck needs to work, it doesn’t hurt a bit if it’s fun to drive, as well.

While the 2021 GMC Sierra 3500 is designed with a specific purpose of towing and stowing in mind, the available configurations and options make it a vehicle that can be driven any day, for any reason. In a world where drivers may not have the luxury of having a work truck and a daily driver on the side, it’s incredibly helpful of GMC to design a truck that can be with drivers every mile of the way. From dropping the kids off at school to running to the store for a gallon of milk, this truck maintains surprisingly lithe drivability behind the powerful facade.