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The 2027 GMC Sierra 2500HD‘s new Duramax 8.3L Turbo-Diesel delivers 555 hp and 1,230 lb-ft of torque. That diesel output exceeds the Ram 2500’s Cummins diesel at 430 hp and 1,075 lb-ft. Compare trims, towing ratings, and technology below, then get updates on upcoming Sierra 2500HD availability at Greg Hubler Buick GMC.
For buyers who prioritize towing capacity, the 2027 Sierra 2500HD holds the advantage. Its available Duramax 8.3L diesel supports up to 23,100 lbs of maximum available towing versus the Ram 2500’s 20,000-lb diesel ceiling.
The Ram 2500 counters with a stronger published payload rating and an extensive trim lineup that includes unique body configurations. Buyers who prioritize towing muscle, segment-first steering technology, and a refined trailering tech suite will find the Sierra 2500HD is the stronger choice. Buyers whose work prioritizes payload, or who need a Mega Cab or Power Wagon configuration, may lean toward the Ram.
| Category | 2027 GMC Sierra 2500HD | 2027 Ram 2500 |
|---|---|---|
| Standard Engine | 6.6L V8 Gas | 6.4L HEMI V8 |
| Gas Horsepower | 412 hp | 405 hp |
| Gas Torque | 472 lb-ft | 429 lb-ft |
| Available Diesel | Duramax 8.3L Turbo-Diesel V8 | 6.7L Cummins HO Turbo Diesel I6 |
| Diesel Horsepower | 555 hp | 430 hp |
| Diesel Torque | 1,230 lb-ft | 1,075 lb-ft |
| Transmission | Allison 10-speed automatic | 8-speed automatic |
| Max Towing (diesel) | 23,100 lbs | 20,000 lbs |
| Payload | 2027 maximum payload rating not yet announced | 4,580 lbs (gas) |
| Seating | 6 | 6 |
| Basic Warranty | 3 yr / 36,000 mi | 3 yr / 36,000 mi |
| Powertrain Warranty | 5 yr / 60,000 mi | 10 yr / 100,000 mi |
The Sierra 2500HD’s standard 6.6L V8 gas engine edges the Ram’s standard 6.4L HEMI V8 in both output metrics. The Sierra produces 412 hp and 472 lb-ft of torque, while the Ram’s HEMI V8 produces 405 hp and 429 lb-ft. Both pair a capable V8 gas engine with an automatic transmission, but the Sierra uses a 10-speed Allison unit, which is a transmission with a proven commercial and fleet reputation that adds more ratio steps for optimized shift management under load.
The diesel gap is where this comparison separates more clearly. The new Duramax 8.3L Turbo-Diesel V8 in the Sierra generates 555 hp and 1,230 lb-ft of torque. The Ram’s available High-Output 6.7L Cummins I6 produces 430 hp and 1,075 lb-ft.
The Sierra 2500HD reaches up to 23,100 lbs of maximum available towing versus 20,000 lbs for the Ram 2500. That 3,100-lb difference can matter for buyers pulling heavier fifth-wheel, equipment, or recreational trailers.
The Sierra 2500HD also introduces two segment-first technologies that affect how the truck drives under load. Electric rack-and-pinion power steering replaces the hydraulic systems typical in heavy-duty trucks, providing more precise feedback especially when maneuvering a trailer. The eBoost electronic brake boost system enlarges the effective braking capacity through improved front brake hardware and mechanics, reducing stopping distances when towing. Neither of these features is available on the Ram 2500.
Both trucks seat six passengers. The Sierra 2500HD’s AT4X trim arrives with 16-way heated and ventilated power front seats including a massage feature standard. The Denali Ultimate also includes 16-way power seats with a massage feature in an exclusive Alpine Umber full-grain leather interior with authentic Paldao wood. The Denali pairs 12-way heated and ventilated front seats with Forge perforated leather.
The Ram 2500 offers a 40/20/40 split-folding bench or available bucket seats up front and three different 60/40 rear seating configurations. Its Mega Cab trim adds class-exclusive reclining and forward fold-flat rear seats that the Sierra’s crew cab body does not replicate. The Ram also offers an available RamBox cargo management system and class-exclusive in-floor rear storage, which add organized utility to the bed and cabin that the Sierra does not specifically offer.
On audio, the Ram’s available Harman Kardon system brings 17 speakers and 900 watts. The Sierra counters with an available 12-speaker Bose Premium Series system. Both serve premium cabin listening, but the Ram’s wattage is higher.
The Sierra 2500HD’s available tech stack includes a 13.4-inch Premium GMC Infotainment System, a 12.3-inch digital Driver Information Center, and a 15-inch multicolor Head-Up Display. The Ram’s available 14.5-inch Uconnect 5 NAV touchscreen is larger than the Sierra’s infotainment display, and the Ram adds a class-exclusive available 10.25-inch front passenger interactive display that the Sierra does not offer.
The Sierra’s ProGrade Trailering System, available on SLT and above, brings an In-Vehicle Trailering App and up to 14 camera views for trailering. The Ram offers an available Surround View Camera, available trailer tire pressure monitoring, and a digital rearview mirror with tow mode camera capability. Both systems give the driver substantial visibility and trailering awareness, but the Sierra’s 14-camera view count is notable for complex trailer setups.
On standard safety, the Ram 2500 includes Forward Collision Warning with Active Braking, Adaptive Cruise Control, Lane Departure Warning, Pedestrian Detection, and Blind-Spot Alert as standard items. The Sierra 2500HD includes Adaptive Cruise Control with trailering capability, a Trailer Brake Controller, the segment-first eBoost braking system, and segment-first electric power steering on the Pro trim as standard features.
Both trucks overlap on Adaptive Cruise Control. The Ram layers in more traditional passive safety assists as standard across the lineup. The Sierra leads in trailering-specific tech, particularly the eBoost system and steering precision.
The Sierra’s AT4X trim debuts Terrain Mode for the Sierra HD, which adjusts shift mapping, traction control, and adds automatic braking for low-speed off-road maneuvers. The Ram counters with the Power Wagon, which offers a factory-installed integrated front winch, and the Rebel, both class-exclusive features for off-road-oriented HD truck buyers.
Both trucks carry a matching 3-year / 36,000-mile basic warranty. The Ram 2500 offers a significantly longer 10-year / 100,000-mile powertrain warranty, which is a notable ownership consideration, especially for buyers who plan to keep a working truck for many years.
The Sierra’s standard Trailering Package, Trailering Mirrors, and Trailer Brake Controller on the Pro trim mean that even the entry-level trim arrives ready to work without requiring buyers to stack option packages before the truck can tow at capacity. The Ram similarly ships with snowplow prep capability, including a 220-amp alternator and snowplow wiring, as standard equipment on the base Tradesman, giving it an out-of-the-box commercial edge for municipal and fleet buyers.
The Ram’s available 50-gallon fuel tank on Crew Cab models with an 8-foot bed extends range between fill-ups beyond what a standard tank allows. Buyers who operate long routes or in remote areas with limited fuel access will find that a relevant ownership benefit.
GMC has not yet announced a 2027 maximum payload rating for the Sierra 2500HD, so this comparison does not assign a payload figure to the truck. The Ram 2500’s published gas payload rating is 4,580 lbs.
For drivers in Marion and the surrounding area whose primary need is pulling trailers, the Sierra 2500HD’s 23,100-lb maximum available towing rating provides additional capability beyond the Ram 2500’s 20,000-lb maximum. Commercial contractors, agricultural operators, and heavy equipment haulers who regularly approach that threshold may find the Sierra’s additional towing capacity particularly valuable.
The 2027 GMC Sierra 2500HD has not arrived at Greg Hubler Buick GMC yet and is expected to become available in late 2026.
Shoppers interested in the upcoming truck can contact the dealership for release updates and availability information, and help comparing the 2027 Sierra 2500HD’s gas and diesel configurations.
In the meantime, buyers can browse current Sierra HD inventory, value a trade, or speak with the Greg Hubler Buick GMC team about which heavy-duty configuration best fits their towing and hauling needs.
The Sierra 2500HD offers up to 23,100 lbs of maximum available towing, compared with up to 20,000 lbs for the Ram 2500. That gives the Sierra a 3,100-lb advantage at the trucks’ published maximum towing ratings.
The Sierra 2500HD leads with 555 hp from the new Duramax 8.3L Turbo-Diesel V8. The Ram 2500’s High-Output Cummins I6 produces 430 hp.
The Ram 2500 has a published maximum gas payload rating of 4,580 lbs. GMC has not yet announced the 2027 Sierra 2500HD’s maximum payload rating, so a direct payload comparison cannot yet be made.
The Ram 2500 offers a 10-year / 100,000-mile powertrain warranty, which exceeds the Sierra 2500HD’s 5-year / 60,000-mile powertrain warranty. Both carry a 3-year / 36,000-mile basic warranty.
The Sierra 2500HD introduces segment-first electric rack-and-pinion power steering and the segment-first eBoost electronic brake boost system, neither of which is available on the Ram 2500.
Yes. The Ram’s available Uconnect 5 NAV touchscreen measures 14.5 inches, compared to the Sierra’s available 13.4-inch Premium GMC Infotainment display.
The 2027 Sierra HD is expected to become available in late 2026. Contact Greg Hubler Buick GMC in Marion for release updates and upcoming availability information.
Both offer serious off-road capability. The Sierra 2500HD AT4X adds Terrain Mode, Multimatic DSSV dampers, and a 1.5-inch lifted suspension. The Ram counters with the Power Wagon and Rebel, including access to a factory-installed front winch.