2025 GMC Sierra 2500HD / 3500 HD Expert Review
Reviewed by Billy Rehbock
For the ultimate heavy-duty truck in GMC’s lineup, there’s the 2025 Sierra 3500HD, fresh off 2024’s major update. This year, the Sierra 3500HD carries over with a series of small tweaks to its trim structure, with tech and safety features headlining the changes. Rivals include other one-ton trucks such as the Ford F-350 Super Duty, Chevrolet Silverado 3500HD, and Ram 3500 Heavy Duty.
- What’s New
- A two-tone 20-inch wheel design
- Available Universal Wheel Module
- Standard cruise control
- Standard trailer brake controller
- Front and Rear Park Assist included with Pro Safety Plus, Sierra HD Pro Safety Plus, and Fleet Convenience packages
- AT4 and Denali trims receive standard adaptive cruise control
- GMC logo added to spray-on bedliner
- Standard instrument panel 120-volt power outlet for SLT trim
- Pickup bed delete is not available on Crew Cab SLT
- Dealer-installed rear wheelhouse liners available, standard on Denali and Denali Ultimate Dual Rear Wheel models
- MultiPro tailgate now available on SLE
- Three 20-inch wheel designs discontinued
- Redwood Metallic discontinued
- Power take-off no longer offered on RWD models
- E85 FlexFuel capability no longer offered with regular cab
What We Think
The 2025 GMC Sierra 3500HD improves upon the pre-refresh model in a number of key metrics. Perhaps most crucially, its cabin receives an attractive design decked out with upscale materials. Second, the gasoline engine is paired with an Allison 10-speed automatic transmission that delivers quicker and smoother shifts.
Despite successful updates to the interior, exterior revisions haven’t saved the Sierra 3500HD’s garish maw. And though GMC added a suite of standard active safety tech, GM’s Super Cruise highway assistance feature continues to elude the automaker’s HD truck. Finally, we appreciate the GMC’s locomotive-like towing prowess, but the Ram 3500 continues to lead the heavy-duty segment.
Those who can look past a few flaws will appreciate the niche that the GMC Sierra 3500HD has carved in the heavy-duty pickup market. Doubling down on luxurious materials and refining powertrains has gone a long way for GMC. Look elsewhere if ultimate towing capability is your first priority, but consider the Sierra 3500HD if you’re in the market for a superbly well-rounded truck.
Performance
GMC offers the 2025 Sierra 3500HD with standard RWD and available 4WD. However, the higher-end Denali or AT4 trims include 4WD but are not offered with RWD.
As default, the 2025 GMC Sierra 3500HD receives a 6.6-liter V-8 paired with an Allison 10-speed automatic transmission. The gasoline engine develops 401 hp and 464 lb-ft of torque. As an upgrade, GMC offers a Duramax turbocharged diesel V-8 developing 470 hp and 975 lb-ft of torque. In its pre-refresh spec, which only developed 445 hp and 910 lb-ft of torque, the diesel Sierra 3500HD accelerated from 0 to 60 mph in 6.9 seconds. We expect the updated model to be a hair quicker with its increased output.
Cab and Bed Options
Standard versions of the 2025 GMC Sierra 3500HD utilize a two-door regular cab configuration, seating two or three passengers. You can also option four-door examples in double or crew cab configurations, with seating for up to six passengers.
Double cabs and crew cabs can be paired with the standard 82.3-inch bed. Choosing the regular, double, or crew cab allows you to equip the long bed, which measures 98.3 inches. Regardless of which bed you choose, the width measures 71.4 inches. The dually layout is exclusive to the Sierra 3500HD’s long bed configurations. Available for either bed, GMC’s MultiPro tailgate offers utility as a bed step, worktable, or cargo organizer.
Safety Ratings and Features
Historically, heavy-duty trucks have been light on active safety equipment. The 2025 GMC Sierra 3500HD bucks that trend with a decent suite of standard features, including front automatic emergency braking with pedestrian detection, lane departure warning, and automatic high-beams. New for 2025, all models are equipped with cruise control and a trailer brake controller. Other available features include adaptive cruise control, front and rear parking sensors, cross-traffic alert with automatic braking, and trailer blind-spot monitoring.
Payload and Towing Capacities
Equipped with the crew cab and standard bed, the 2025 GMC Sierra 3500HD RWD diesel model’s payload rating maxes out at 4,162 pounds. To achieve the maximum capacity, configure the regular cab, long bed, RWD dually gasoline variant. Its payload tops out at 7,290 pounds. Maximum towing is certified at 20,000 pounds with the diesel engine and a conventional hitch. If you opt for a fifth wheel, that figure rises to 31,800 pounds.
Technology
The most basic versions of the 2025 GMC Sierra 3500HD use a 7.0-inch touchscreen with features such as Bluetooth audio streaming, Apple CarPlay, and Android Auto. A 3.5-inch monochromatic display comes standard on this entry-level Pro trim.
All other models receive a 13.4-inch infotainment touchscreen with wireless Android Auto and Apple CarPlay. Google built-in apps and features include Google Maps, Google Assistant, and the Google Play Store. Every trim above the Sierra 3500HD Pro comes equipped with a 12.3-inch digital gauge display. Other available features include a 15.0-inch head-up display, a digital rearview mirror, 360-degree cameras with angles focusing on the bed or trailer, and a wireless charging pad. A six-speaker audio arrangement is standard, though seven- and 12-speaker configurations are available on higher-end models.
The Fanciest One-Ton Truck
Those hoping to blend heavy-duty activities with sumptuous luxury should spring for the 2025 GMC Sierra 3500HD Denali Ultimate. Exterior features include 20-inch wheels and dark chrome trim accents. Inside the cabin, GMC equips premium leather, wood, and microfiber touches. In addition to providing massages, the 16-way adjustable front seats provide heating and ventilation. Other tech includes a digital rearview mirror, 12-speaker Bose audio system, and a 360-degree camera.
Which 2025 GMC Sierra 3500HD Trim Level Is Best?
GMC offers the 2025 Sierra 3500HD in six trims: Pro, SLE, SLT, AT4, Denali, and Denali Ultimate. For the best of all worlds, we suggest going for the modest SLE trim, 4WD, and the Duramax turbodiesel powertrain. Skipping the lowest Pro grade equips the better interior displays while saving money for the gutsier engine and 4WD layout. The gulf between the Sierra 3500HD SLE and SLT is steep, to the tune of approximately $8,000, so we think this configuration serves as a solid blend of utility and comfort.
