Pre-Owned 2026 GMC Sierra 2500 HD AT4 For Sale Warminster, PE

WOW! Power, presence, and premium capability come together in this 2026 GMC Sierra 2500HD AT4—available now at O'Neil GMC.Finished in striking Sterling Metallic with a bold Jet Black interior featuring Kalahari accents, this heavy-duty truck looks just as tough as it performs. With only 3,124 miles, it’s barely broken in and ready for whatever job—or adventure—you have in mind.Under the hood, the legendary 6.6L V8 engine pairs with a 10-speed automatic transmission to deliver serious towing power and smooth, controlled performance. Combined with 4WD capability, the AT4 trim is built to handle rugged terrain, tough worksites, and off-road excursions with confidence.Step inside the spacious Crew Cab, and you’ll find a refined interior that balances durability with upscale comfort. The AT4 is known for its premium touches, advanced technology, and driver-focused design—making long drives, job days, and weekend escapes equally enjoyable.If you’ve been searching for a heavy-duty truck that blends raw strength with modern comfort and low mileage, this Sierra 2500HD AT4 is the one to see. Carfax One Owner Clean Car!Opportunities like this don’t sit long—call 215-672-0900 today to speak with our sales team or schedule your visit. Better yet, stop by O'Neil GMC and experience this powerhouse in person.Our model lineup is second to none! Make sure you swing in today to get an incredible deal on many new and used Buick and GMC models. These vehicles come packed full of features including a one-of-a-kind navigation system that will get you to any location efficiently and safely. Have kids and want to keep them entertained? Our Rear Seat DVD equipped vehicles will have them settled in for those long trips. The average family is getting larger and larger so make sure to check out our vehicles with the extra space with third row seating that can fit kids, dogs, adults, and more! Of course, when it gets chilly in those winter months, features like climate control and heated leather seating are exactly what your body needs for an early morning trip into work. Check out all of these features and more in our stock of vehicles. Other features include but are not limited to Power Moonroof, New Battery, New Tires, Non-Smoker Interior, Paddle Shifters, One Owner Carfax Certified, Premium Wheels, 30+ MPG, Premium Cloth Seating, New Brakes, Premium Sound System, Rear Bucket Seats, Remainder of Factory Warranty, Rear Back-Up Sensors, Remote Keyless Entry, Service Records Available, Steering Wheel Controls, Remote Start, Tow Package, Traction Control, XM Radio, USB Ports, and much more! Price excludes tax, tags, title, license, and dealer fees, additional rebates may apply. See our specials for more details.