AdChoices
2025 GMC SIERRA 2500HD AT4 4WD 6.6L DURAMAX DIESEL AT4 PREMIUM PLUS TECHNOLOGY PACKAGE 5TH WHEEL PREP SUMMIT WHITE LANCASTER PA
This 2025 GMC Sierra 2500HD AT4 4WD is powered by the 6.6L Duramax V8 turbodiesel paired with the 10-speed automatic transmission. Finished in Summit White with Jet Black/Kalahari leather, this is a loaded AT4 with the AT4 Premium Plus Package, Technology Package, sunroof, X31 Off-Road Package, and factory Gooseneck/5th Wheel Prep.
The Duramax delivers 470 horsepower and 975 lb-ft of torque, giving the Sierra HD serious pulling power for heavy trailers, equipment, or campers. The 10-speed keeps that torque readily available while making the truck surprisingly smooth on the highway.
The AT4 combines HD capability with legitimate off-road equipment. This truck has a 2-speed transfer case, Hill Descent Control, X31 Off-Road Package, and high-clearance off-road steps. The AT4's blacked-out exterior details and Summit White paint give it a sharp, aggressive look without sacrificing the upscale feel of the trim.
Inside, the AT4 Premium Plus and Preferred packages make this much more than a work truck. You get heated and ventilated front leather seats, heated second-row outboard seats, power sunroof, Bose premium audio, wireless charging, remote start, a power sliding rear window, and premium floor liners.
The Technology Package is especially useful on a truck this size. It adds a massive 15-inch Head-Up Display, HD Surround Vision, Rear Camera Mirror, and Bed View Camera. The Bed View Camera lets you keep an eye on cargo or a gooseneck connection without constantly getting out of the truck.
For towing, this one is set up right from the factory with the Gooseneck/5th Wheel Prep Package, Trailer Camera Provisions and Trailer Viewing Software, Trailer Side Blind Zone Alert, and additional trailer camera capability. That combination is a big advantage for someone actually planning to use an HD truck for heavy towing.
The bed is protected by a factory GMC spray-on bedliner and includes LED cargo lighting plus a 120-volt power outlet. There's another 120-volt outlet inside the cab for tools and electronics.
Mileage is another strong pointthis Sierra is 4,326 miles below the market average.
If you're looking for a premium diesel HD that can tow hard during the week and still be comfortable on a long road trip, this is an excellent setup. The combination of Duramax power, AT4 Premium Plus, Technology Package, sunroof, 5th-wheel prep, cameras, and off-road equipment makes this a very complete Sierra 2500HD.
See it today at Mark Martin Motors in Ephrata, serving Lancaster, Lititz, Lebanon, and York. Call or message us to check availability or schedule your test drive.