“I really like the exterior design of the 2015 GMC 2500 HD pickup. The style appealed to me as well. The interior is very stylish with all the bells and whistles. This is the first diesel motor I've owned, and it's loaded with power.”
2015 GMC Sierra 2500: What's New, Specs & Features
Last updated August 13, 2026
The 2015 GMC Sierra 2500 is a full redesign and the first year of a new generation. Its biggest change is an all-new cab and body that make this heavy-duty truck quieter, roomier and more modern.
About the 2015 GMC Sierra 2500
2015 redesign, first year of the K2XX Sierra HD generation.
GMC positions the Sierra 2500 HD as a premium heavy-duty pickup: a truck built to tow, haul and handle jobsite duty, but with a quieter cabin and more upscale interior than a stripped-down work rig. The core appeal is heavy-duty capability without giving up day-to-day comfort, with Sierra trims ranging from basic work use to the luxury-focused Denali. Compared with rivals, GMC leans on cabin quietness, cargo-box usefulness and a more polished look.
The lineup runs from the straightforward Base work truck, with Tow/Haul mode and trailer-sway control, through the more everyday-friendly SLE and comfort-focused SLT. SLT has an 8-inch touchscreen and Bose audio, while Denali tops the range with heated and cooled leather seats, navigation and a customizable 8-inch driver display.
What changed, by category
Structural
A new cab brings more Crew Cab rear-seat legroom, while the Double Cab joins the body-style range. Inlaid doors, triple door seals and other body work reduce cabin noise. The cargo box gains built-in rail protection and movable upper tie-down points.
Styling
The entire Sierra 2500 range gets a redesigned exterior and front end, including projector-beam headlights, along with a new dashboard and cabin layout.
Safety
Forward Collision Alert and Lane Departure Warning were added as optional safety features.
Tech
Denali gains standard navigation and an 8-inch touchscreen, while the touchscreen becomes standard on SLT. Bluetooth and USB ports become standard on SLE.
Powertrain
The natural-gas powertrain was dropped from the Denali trim.
Trim lineup
The Base trim was added, and the Work Truck trim was dropped.
2015 GMC Sierra 2500 specs and features by trim
| Feature | ||||
|---|---|---|---|---|
| Engine | V8, CNG, 6.0L / V8, Flex Fuel, 6.0 Liter / V8, Turbo Dsl, 6.6L / V8, Compressed Natural Gas, 6.0 Liter | V8, CNG, 6.0L / V8, Flex Fuel, 6.0 Liter / V8, Turbo Dsl, 6.6L | V8, CNG, 6.0L / V8, Flex Fuel, 6.0 Liter / V8, Turbo Dsl, 6.6L / V8, Compressed Natural Gas, 6.0 Liter / V8, Turbo Diesel, 6.6 Liter | V8, Flex Fuel, 6.0 Liter / V8, Turbo Dsl, 6.6L |
| Transmission | Auto, 6-Spd Allison OD / Auto, 6-Spd HD Overdrive / Auto, 6-Spd Allison HD | Auto, 6-Spd Allison OD / Auto, 6-spd Allison OD | Auto, 6-Spd HD Overdrive / Automatic, 6-Spd HD w/Overdrive | Auto, 6-Spd Allison OD |
| Drivetrain | 4WD | 4WD | 4WD | 4WD |
| Fuel Type | Natural Gas / Flexible Fuel / Diesel | Natural Gas / Flexible Fuel / Diesel | Natural Gas / Flexible Fuel / Diesel | Flexible Fuel / Diesel |
| Horsepower | 360–397 hp | 360–397 hp | 360–397 hp | 360–397 hp |
| Torque | 380–765 lb-ft | 380–765 lb-ft | 380–765 lb-ft | 380–765 lb-ft |
| Max Towing | 13000 lb | 13000 lb | 13000 lb | 13000 lb |
| Rear Legroom | 34.6–40.9 in | 34.6–40.9 in | 34.6–40.9 in | 40.9 in |
| Seats | 3–6 | 5 | 3–6 | 5 |
| Doors | 2–4 | 4 | 2–4 | 4 |
| Alarm System | ||||
| Hill Descent Control | ||||
| Lane Departure Warning | ||||
| Park Assist | ||||
| Rear View Camera | ||||
| Alloy Wheels | ||||
| Auto-Dimming Exterior Mirrors | ||||
| Fog Lights | ||||
| Heated Mirrors | ||||
| LED Headlights | ||||
| Power Moonroof | ||||
| Power Folding Exterior Mirrors | ||||
| Power Mirrors | ||||
| Privacy Glass | ||||
| Side Steps | ||||
| Trailer Hitch Receiver | ||||
| Front DVD Entertainment System | ||||
| Navigation System | ||||
| Rear DVD Entertainment System | ||||
| Satellite Radio | ||||
| Smartphone Interface | ||||
| Subwoofer | ||||
| Touch Screen Monitor | ||||
| USB Ports | ||||
| Auto-Dimming Interior Mirror | ||||
| Cooled Seats | ||||
| Dual Power Front Seats | ||||
| Dual-Zone Climate Control | ||||
| Heated Front Seats | ||||
| Heated Steering Wheel | ||||
| Integrated Garage Door Opener | ||||
| Leather Seats | ||||
| Leather-Wrapped Steering Wheel | ||||
| Memory Driver's Seat | ||||
| Power Adjustable Pedals | ||||
| Power Driver Seat | ||||
| Remote Start | ||||
| Remote Keyless Entry | ||||
| Tilt Wheel | ||||
| Tilt/Telescoping Steering Wheel | ||||
Frequently asked questions
Is the 2015 GMC Sierra 2500 a redesign year?
Yes. The 2015 GMC Sierra 2500 begins a new generation with a redesigned body and cab, updated front-end styling, a quieter interior and a new dashboard layout.
How did the cab change for the 2015 GMC Sierra 2500?
The 2015 GMC Sierra 2500 has a quieter, roomier cab. Crew Cab rear-seat legroom increased, and new inlaid doors, triple door seals and other sealing work help keep road and wind noise out.
Did the 2015 GMC Sierra 2500 add a Double Cab?
Yes. The Double Cab joined the GMC Sierra 2500 range for 2015 as part of the full redesign.
What technology became standard on the 2015 GMC Sierra 2500?
Several features became standard for 2015: Denali gained navigation and an 8-inch touchscreen, SLT gained a standard touchscreen, and SLE gained standard Bluetooth and USB ports.
Does every 2015 GMC Sierra 2500 have Forward Collision Alert and Lane Departure Warning?
No. Forward Collision Alert and Lane Departure Warning were optional safety features introduced with the 2015 redesign, so their presence varies from truck to truck.
2015 GMC Sierra 2500 Reviews
What owners are saying about the 2015 GMC Sierra 2500.
4.2
2015 GMC Sierra 2500
(162 reviews)
“The headlights are definitely a failure! Extremely dim... Very stressful to drive at night.”
“Headlights are not good. For the money you spend on this truck you should have HID or LED headlights.”