2025 GMC Sierra HD Model Research

The 2025 GMC Sierra HD comes in 7 distinct trims: the utilitarian Pro, SLE, and SLT, the rugged AT4 and AT4X, and the lavish Denali and Denali Ultimate. The Pro trim offers a no-frills, functional design, highlighted by animated LED projector headlamps with daytime running lamps, built for work. The SLE and SLT upgrade to a more refined appearance while maintaining the truck’s rugged character, with conveniences like cab-mounted cargo lamps, animated taillamps and fog lamps, rain-sensing wipers, and the MultiPro™ Tailgate. The AT4 trim is designed for the adventurous, featuring a lifted suspension, off-road tires, and skid plates for enhanced durability. The AT4X takes off-road capability even further, offering a up to 35-inch mud-terrain tires, heavy-duty skid plates, and a higher level of performance with advanced suspension and greater ground clearance. At the top of the lineup, the Denali trim provides the highest level of luxury, with chrome accents, polished wheels, and a signature grille, but the Denali Ultimate goes above and beyond. Its Vader Chrome grille, illuminated power assist steps, 20-inch ultra-bright machined wheels, and premium finishes hint at the indulgence within. Every trim offers customization options and a wide palette of colors to make it your own.

Under the hood, the 2025 GMC Sierra HD offers 2 powerful engine options. The standard 6.6L V8 gas engine provides 401 hp and 464 lbs.-ft. of torque, delivering the power needed for most heavy-duty tasks. For even more muscle, the 6.6L Duramax® Turbo-Diesel V8 engine produces 470 hp and a staggering 975 lbs.-ft. of low-end torque, making it perfect for towing heavy trailers and equipment. Both engines are matched with an Allison® 10-speed automatic transmission—the preferred choice for heavy-duty applications.

Performance is where the 2025 GMC Sierra HD truly shines. Whether equipped with rear-wheel drive or 4WD, this truck is built to handle demanding work environments and diverse road conditions. The turbo-diesel engine in particular offers exceptional towing power, allowing it to haul up to 36,000 lbs., supported by the ProGrade™ Trailering System and up to 14 camera views including a transparent trailer view. The advanced suspension systems, especially in the AT4 and AT4X trims, provide exceptional off-road capability, compounded by a rear e-locking differential and twin-tube shocks to maximize their prowess.

Inside, the 2025 GMC Sierra HD offers a cabin that blends luxury with functionality. The interior features spacious seating for up to 6 passengers, depending on the configuration, and provides ample legroom for both front and rear passengers. Premium materials, including leather upholstery and real wood accents, are available on higher trims such as the SLT, Denali, and Denali Ultimate. This last trim truly indulges you with 16-way heated, ventilated, massaging seats in full-grain leather, laser-etched topographical maps of Mt. Denali on open-pore wood. This cabin is outfitted with a 13.4-inch touchscreen—the largest in its class—alongside a 12.3-inch Driver Information Center, while an available 15-inch multicolor Head-Up Display keeps you informed and focused. Wireless smartphone integration and available wireless charging keep you connected and your cabin clutter-free. With ample storage solutions and a versatile center console complementing Best-in-Class Crew Cab front head and legroom, this cabin works for you in every way.

The 2025 GMC Sierra HD comes standard with GMC’s ProGrade™ Trailering System, which includes features like Trailer Sway Control and Hitch Guidance, making towing safer and more manageable. Additional standard features include Forward Collision Alert, Lane Departure Warning, and Automatic Emergency Braking, all of which help enhance safety during everyday driving. Higher trims like the Denali Ultimate offer even more advanced safety technologies, including Adaptive Cruise Control, Rear Cross Traffic Alert, and the Surround Vision Camera. With these features, this truck covers you from every angle.