2026 GMC Sierra HD Gainesville TX

When the job demands maximum strength, advanced trailering control, and a premium command center behind the wheel, the 2026 GMC Sierra HD answers without hesitation. Designed for serious work and engineered to handle extreme loads, this heavy-duty pickup offers towing capability of up to 36,000 pounds along with technology that makes even the toughest hauls feel controlled and confident.

From large equipment trailers to fifth-wheel RVs, the Sierra HD is built for North Texas drivers who rely on their truck every day. With a wide range of trims, two proven powertrains, and professional-grade features throughout, it delivers the muscle of a work truck with the comfort of a luxury vehicle.

Explore available 2026 GMC Sierra HD models at Glenn Polk Auto in Gainesville, TX and see why so many drivers trust GMC when the work gets serious.

The 2026 Sierra HD is engineered for heavy-duty performance with two powerful engine options. The standard 6.6L gas V8 produces 401 horsepower and 464 lb-ft of torque, delivering dependable strength with towing capability up to 22,500 pounds when properly configured. For maximum pulling power, the available 6.6L Duramax Turbo-Diesel V8 cranks out 470 horsepower and an industry-leading 975 lb-ft of torque, enabling towing ratings up to 36,000 pounds with dual rear wheels and a gooseneck hitch.

Both engines are paired with the proven Allison® 10-speed automatic transmission, providing smooth power delivery and confident control under load. The diesel model includes an integrated exhaust brake to help manage speed and stability when descending steep grades while towing.

Trailering confidence is a cornerstone of the Sierra HD. ProGrade™ Trailering Technology offers up to 14 available camera views, including Transparent Trailer View, hitch guidance, and rear side views to simplify connecting and maneuvering large trailers. Adaptive Cruise Control with Trailering adjusts automatically for the added weight of a trailer, helping reduce driver fatigue on long hauls. A trailer brake controller comes standard across all trims, and available front and rear parking sensors enhance low-speed awareness on job sites and in tight spaces.

Inside the cabin, the Sierra HD delivers a high-tech, driver-focused environment. The available 13.4-inch touchscreenanchors the dash and supports Google Built-In for navigation, voice control, and apps. A 12.3-inch digital driver displaykeeps critical information front and center, while the available 15-inch Head-Up Display projects speed, navigation, and safety alerts directly onto the windshield. Premium options include 16-way power-adjustable front seats with massage, a Bose® premium sound system, wireless Apple CarPlay® and Android Auto™, and available Wi-Fi connectivity, proving that a heavy-duty truck can also be a comfortable place to spend long days.

At Glenn Polk Auto, we understand what heavy-duty truck owners expect because we’ve been serving North Texas drivers for decades. Conveniently located just off I-35, our Gainesville dealership makes it easy for customers throughout the region to find the right Sierra HD configuration for their workload. Our experienced sales team can walk you through engine options, trailering setups, and trim differences to ensure your truck fits how you actually use it. And with GM-certified technicians in our service department, you’ll have expert support long after you drive off the lot.