When it comes to pickup trucks, brand loyalty runs deep. Many truck owners swear by a single brand for life, but over the last four years, I’ve owned five pickups from Ram, Ford, and GMC. As I reflect on an entire year with my 2024 GMC Sierra 3500 HD AT4, I find myself pleasantly surprised—this GMC is the best truck I’ve owned. Coming from a self-proclaimed anti-GM truck guy, that’s saying something.
After a year of ownership, nearly 40,000 kilometers, and several cross-country trips from British Columbia to Ontario (including a run towing a cargo trailer), this Duramax-powered Sierra 3500 HD AT4 has proven itself as a capable, comfortable workhorse that excels in performance, design, and tech.
Power and Performance: Duramax Muscle for Serious Towing
The 2024 Sierra 3500 HD AT4 is built for heavy-duty tasks, powered by a 6.6-liter Duramax Turbo Diesel engine delivering 470 horsepower and 975 lb-ft of torque. That power translates to effortless towing, whether hauling a fully loaded cargo trailer or pulling my 2015 Dodge Challenger Hellcat. This engine is complemented by a smooth-shifting 10-speed transmission, providing the torque and control you need for towing even on hilly or challenging terrain.
On recent trips across Canada, including one while towing a hefty cargo trailer, the Sierra 3500 HD AT4 handled the journey effortlessly. The truck’s stability and control are exceptional, even when navigating steep grades and varying road conditions. GMC’s towing technology suite—complete with trailer sway control, multiple camera views, and an integrated trailer brake controller—makes towing feel secure and manageable. With these tools, the Sierra handles cross-country hauls with ease, instilling confidence no matter the load or route.
Redesigned Exterior and Interior: A Refreshed, Functional Look
GMC’s 2024 refresh of the Sierra HD lineup brought meaningful changes, particularly in design. The front-end redesign gives the truck a bolder, more modern look, with sleeker headlights and a revamped grille. Rear design updates, including refined taillights, give the Sierra 3500 HD AT4 a standout presence on the road.
Inside, GMC has made significant strides in both design and materials. The new dashboard layout is a big improvement, with controls placed intuitively where you’d expect them. While GMC’s materials may not reach the class-leading luxury of Ram’s top trims, like the Longhorn or Limited, the quality is noticeably better than in previous Sierras. This refreshed design feels upscale but remains practical for a truck built for hard work.
That said, the interior isn’t without its quirks. The placement of controls for the transfer case, drive modes, and auxiliary lights down near the driver’s left knee is less than ideal. These controls are tough to see and operate without taking your eyes off the road. Additionally, it’s disappointing that GMC hasn’t added a panoramic sunroof, a feature Ford has offered in the Super Duty since 2017. In a segment where details matter, these could be areas for improvement in future models.
Infotainment and Technology: Smooth, Reliable, and Modern
One of the 2024 model’s standout features is the 13.4-inch Android Automotive-based infotainment system. This new setup is intuitive, reliable, and packed with features, performing flawlessly through my extensive use. Wireless Apple CarPlay and Android Auto support allow for easy smartphone integration without the hassle of cables, and the interface is responsive, with just the right level of customization.
Whether on a long-haul drive or a short run around town, the infotainment system has been a valuable addition, adding convenience and functionality to the driving experience. GMC’s system is thoughtfully designed and offers quick access to essential functions, making it one of the highlights of the 2024 refresh.
Comfort and Seating: Designed for Long-Haul Comfort
Seat comfort can make or break a long drive, and the Sierra 3500 HD AT4 impresses in this department. Online reviews have been mixed on GM truck seat comfort, but I’ve found the heated and cooled leather seats to be comfortable and supportive. After multiple cross-country trips, I’ve experienced no fatigue, which speaks to the seat design’s support for extended driving.
Passengers have also praised the seat comfort, reinforcing my own experience. Compared to my previous 2020 Ram 3500 Limited, where seat discomfort was a frequent issue on long drives, the Sierra’s seats are a major improvement. While I had no issues with Ram 1500 seats, the heavy-duty Ram’s seats were less comfortable for long trips, making the Sierra 3500 HD AT4’s comfort a welcome surprise.
Fuel Efficiency and Driving Impressions
In addition to towing and comfort, the Sierra 3500 HD AT4 has shown impressive fuel efficiency for its size and power. On longer highway drives, I’ve seen 20 MPG, and it averages around 14 MPG in town—a solid figure for a heavy-duty truck. The 10-speed transmission consistently finds the right gear, providing smooth shifts and ample acceleration when needed.
Driving the Sierra 3500 HD AT4 has been a consistently positive experience. Despite its size, the truck handles well and provides a steady, controlled ride. The suspension smooths out bumps without compromising the ruggedness needed for towing and hauling. In my opinion, GM’s HD lineup offers the best ride quality in the heavy-duty segment, striking an impressive balance between comfort and capability.
The available driver-assistance features, such as adaptive cruise control, have also added convenience on long journeys, enhancing both safety and ease. The truck’s powertrain has been flawless, and I’ve had no issues over the year of ownership—no repairs, just regular maintenance and a few recalls.
Final Thoughts: The 2024 GMC Sierra 3500 HD AT4 Is a Top Contender
The 2024 GMC Sierra 3500 HD AT4 brings a lot to the table, blending performance, practicality, and comfort in a well-rounded package that meets the demands of both work and travel. The recent updates have truly elevated the Sierra, especially in terms of interior quality and functionality. If you’re looking for a heavy-duty truck that combines impressive muscle with surprising comfort and refined styling, the GMC Sierra 3500 HD AT4 is an option well worth considering. For a truck that has converted a lifelong GM skeptic, it’s safe to say the Sierra 3500 HD AT4 is built to impress.
