GMC’s 2025 Sierra 2500 HD: Everything That’s New And Different vs. 2024

GMC’s 2025 Sierra 2500 HD receives a variety of relatively small changes and updates consistent with a model year changeover, compared to the 2024 model.

Model Cadence

The 2025 Sierra HD represents the sixth model year of the fourth-gen full-size truck, which was introduced as the 2020 Sierra 2500 HD followed by a mid-cycle refresh for the 2024 Sierra 2500 HD.

The 2500 HD is the three-quarter ton model that slots above the Sierra 1500 in the lineup, offering a different set of engines and greater payload and towing capabilities.

Model Line

There are no changes to the trim levels or available configurations for the 2025 model year.

Exterior

On the outside, the 2025 Sierra 2500 sees the deletion of the Redwood Metallic exterior color (G48).

Redwood Metallic (discontinued)

Additionally, the Spray-on Bedliner (CGN) now has a GMC logo on the back wall of the AT4, AT4X, Denali and Denali Ultimate trims. By comparison, the prior model year featured a trim-specific logo on the back wall:

• AT4 logo on AT4 trim
• AT4X logo on AT4X trim
• Denali logo on Denali and Denali Ultimate trims

From there, the MultiPro Tailgate becomes optional on the SLE trim (QK2). For the 2024 model year, the MultiPro tailgate was standard on the SLE trim, with the “regular” Standard tailgate (QK2) being optional. The Standard tailgate (QK2) becomes standard on the SLE trim for the 2025 Sierra 2500.

Q7J (new for 2025)

Q7R (discontinued)

SKW (discontinued)

SHL (discontinued)

There are also four wheel-related changes, including the addition of one wheel set and the deletion of three existing ones. The new wheel option is the 20-inch Bright face wheels with dark painted pockets (Q7J), while the three deleted wheel options are:

• 20-inch machined aluminum wheel with bright Silver accents (Q7R)
• 20-inch multi-dimensional Chrome aluminum wheels (SKW)
• 20-inch Chrome aluminum wheels (SHL)

Rounding out the exterior changes is the deletion of Rear Park Assist (UD7), which has been replaced by Front and Rear Park Assist (UD5) on Pro and SLE trims. For the 2024 model year, UD7 was optional on Pro and SLE, while UD5 was optional on SLT and standard on AT4, AT4X, Denali, Denali Ultimate. For the 2025 Sierra 2500, UD5 is optional on Pro, SLE and SLT, while being included as standard on AT4, AT4X, Denali, Denali Ultimate.

Finally, the Box Delete option (ZW9) is removed from SLT Crew Cab models. For the 2024 model year, this option was available, albeit for a very brief period of time.

Interior

Three changes are in store to the 2025 Sierra 2500 HD’s interior.

First up, Cruise Control (K34) is now standard on the Pro trim. For the 2024 model year, this feature was optional on the Pro trim and standard on SLE, SLT, and AT4.

Next, Adaptive Cruise Control (KSG) becomes standard on AT4 and Denali trims. For the 2024 model year, ACC was optional on both trims. The AT4X and Denali Ultimate trims continue to include Adaptive Cruise as standard. Alas, Super Cruise remains absent from the options list on the 2025 Sierra 2500 (as well as its even more capable stable mate, the Sierra 3500 HD).

Finally, the Trailer Brake Controller (JL1) becomes standard equipment on the Pro trim level. It was optional for the 2024 model year.

Mechanical

Mechanically, the 2025 Sierra 2500 carries over the two powertrains offered since the 2020 model year, namely the 6.6L gasoline V8 L8T engine and the 6.6L V8 L5P turbo-diesel Duramax.

There are, however, a few minor changes. First, the Universal Vehicle Module (KGU) is added as a new option on all trim levels. This feature enables CAN readability of selected messages utilizing SAE J1939 formatting, offering 10-switchable inputs and outputs, and includes a graphical user interface to customize specific needs with more than 150 operating parameters available to read.

Additionally, the Power Take-Off (PTO) feature has been eliminated from RWD models. For comparison, PTO was available on both RWD and 4WD models for the 2024 model year. As was the case for 2024, PTO remains limited to the Pro and SLE trim levels.

Similarly, E85 fuel capability (FHS) has been removed from Regular Cab models. For the 2024 model year, this feature was available on Regular Cab models with the naturally-aspirated 6.6L V8 L8T engine (gasoline) and the trailer brake controller (JL1).

Finally, the 120-volt power outlet within the instrument panel (KI4) and the 120-volt bed-mounted power outlet (KC9) have become standard on the SLE trim. For the 2024 model year, both were optional on SLE.

Looking Ahead

We expect the current-generation GMC Sierra HD to be available for the 2026 and 2027 model years, at which point the next-gen model will arrive for the 2028 model year. That will be one mode year after the Light Duty GMC Sierra 1500 will get its own overhaul for the 2027 model year.

• See more on the 2027 GMC Sierra
• See more on the 2028 GMC Sierra HD