The 2015 GMC Sierra Denali 2500 is a heavy-duty pickup truck that falls under the Denali trim, which is known for its luxury and premium features. Here are some key specifications and features of the 2015 GMC Sierra Denali 2500:

Engine Options:

The 2015 Sierra Denali 2500 typically comes with a powerful engine to handle heavy-duty tasks. Commonly, it is equipped with a V8 engine, and there may be different options available, such as a gasoline or a diesel engine.
Transmission:

The truck usually comes with an automatic transmission, providing ease of use and convenience.
Towing Capacity:

One of the significant attributes of heavy-duty trucks like the Sierra Denali 2500 is their towing capacity. The towing capacity can vary based on the specific configuration and engine choice but is generally quite high, suitable for towing trailers, boats, or other heavy loads.
Interior Features:

Denali trims are known for their luxurious interiors. The 2015 Sierra Denali 2500 likely comes with high-quality materials, premium leather upholstery, and advanced technology features. It may include a touchscreen infotainment system, navigation, Bluetooth connectivity, and more.
Safety Features:

The truck is expected to have standard safety features, including airbags, stability control, traction control, antilock brakes, and available advanced safety options.
Exterior Styling:

The Denali trim typically features distinctive exterior styling elements, such as chrome accents, unique grille design, and Denali badging.
Four-Wheel Drive (4WD):

Many trucks in this category come with 4WD, enhancing their off-road capability and providing better traction in various driving conditions.
It's important to note that specific features and specifications can vary based on the exact model, trim level, and optional packages that were chosen when the vehicle was originally purchased. If you have a specific question about a particular aspect of the 2015 GMC Sierra Denali 2500, feel free to ask for more detailed information.