The GMC Sierra 2500HD, particularly the variant featuring the 6.6L Duramax Turbo Diesel V8 engine paired with a 10-speed automatic transmission, represents a significant offering in the heavy-duty pickup truck segment. Introduced with the GMTT1XX platform and receiving a facelift in 2024, this configuration is geared towards buyers needing substantial towing and hauling capabilities without sacrificing a degree of refinement. This specific Double Cab Standard Bed model occupies a sweet spot in the Sierra 2500HD lineup, balancing practicality with a more accessible price point compared to the higher trim levels.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD V (GMTT1XX, facelift 2024) Double Cab Standard Bed |
| Type (Engine) | 6.6 Duramax TD V8 (470 Hp) Automatic |
| Start of production | 2023 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7 kg/Hp, 143.3 Hp/tonne |
| Weight-to-torque ratio | 2.5 kg/Nm, 403 Nm/tonne |
| Power | 470 Hp @ 2800 rpm |
| Power per litre | 71.2 Hp/l |
| Torque | 1322 Nm @ 1600 rpm, 975.06 lb.-ft. @ 1600 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L5P |
| Engine displacement | 6604 cm3, 403 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103 mm, 4.06 in. |
| Piston Stroke | 99 mm, 3.9 in. |
| Compression ratio | 16:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | OHV |
| Engine oil capacity | 9.5 l, 10.04 US qt | 8.36 UK qt |
| Coolant | 28.5 l, 30.12 US qt | 25.08 UK qt |
| Kerb Weight | 3280 kg, 7231.16 lbs |
| Max. weight | 4853 kg, 10699.03 lbs |
| Max load | 1573 kg, 3467.87 lbs |
| Fuel tank capacity | 111 l, 29.32 US gal | 24.42 UK gal |
| Permitted trailer load with brakes (12%) | 6577 kg, 14499.8 lbs |
| Length | 6127 mm, 241.22 in |
| Width including mirrors | 2079 mm, 81.85 in |
| Height | 2031 mm, 79.96 in |
| Wheelbase | 3795 mm, 149.41 in |
| Front track | 1731 mm, 68.15 in |
| Rear (Back) track | 1736 mm, 68.35 in |
| Ride height (ground clearance) | 258 mm, 10.16 in |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 10 gears, automatic transmission Allison |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 350×40 mm |
| Rear brakes | Ventilated discs, 360×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | 235/80 R17; 265/70 R17; 245/75 R17; 265/70 R18; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
Overview and Market Positioning
The GMC Sierra 2500HD has long been a mainstay in the American heavy-duty truck market, competing directly with offerings from Ford (F-250/F-350) and Ram (2500/3500). The Sierra, positioned as GMC’s more premium offering compared to the Chevrolet Silverado, aims for a blend of capability and comfort. The 2023-2024 facelift brought updated styling, enhanced technology, and refinements to the interior. The Double Cab configuration provides a useful balance between passenger space and bed length, making it suitable for both work and family use. This particular variant, with the Duramax diesel and 10-speed automatic, is not the entry-level option – that would be the gasoline-powered engines – but it also isn’t the most luxurious trim. It targets buyers who prioritize towing and hauling performance and want a robust powertrain without the added cost of the Denali or AT4 trims.
The Duramax 6.6L L5P Engine
The heart of this Sierra 2500HD is the 6.6-liter Duramax L5P turbo-diesel V8. This engine has been a cornerstone of GMC and Chevrolet’s heavy-duty lineup for years, renowned for its durability and impressive torque output. The 470 horsepower and 975 lb-ft of torque provide exceptional pulling power, making it ideal for towing large trailers, boats, or heavy equipment. The engine utilizes a common-rail fuel injection system and a variable geometry turbocharger to optimize performance and efficiency. A particulate filter is included to meet emissions standards. The L5P engine is known for its relatively long service intervals and robust construction, though diesel engines generally require more specialized maintenance than their gasoline counterparts.
10-Speed Allison Automatic Transmission
Paired with the Duramax engine is the Allison 10-speed automatic transmission. This transmission is a significant upgrade over previous generations, offering smoother shifts, improved fuel economy, and a wider gear ratio spread. The 10-speed design allows the engine to operate in its optimal power band more frequently, enhancing both performance and efficiency. The Allison transmission is also known for its durability and ability to handle the high torque output of the Duramax engine. It features electronically controlled shifts and tow/haul modes optimized for heavy loads.
Comparison with Sierra 2500HD Siblings
The Sierra 2500HD is offered with a range of engine and trim options. Compared to the standard gasoline engines (typically a 6.6L V8), the Duramax diesel provides significantly more torque, making it the preferred choice for heavy towing. While the gasoline engines are less expensive upfront, the diesel offers superior fuel economy when towing and a longer engine lifespan. Compared to the higher-end trims like the Denali, this variant sacrifices some luxury features – such as premium leather interiors, advanced sound systems, and unique exterior styling – but maintains the same core capability. The AT4 trim offers a more off-road focused appearance and some additional off-road hardware, but the Duramax/10-speed combination is available on both the AT4 and this mid-range configuration. Compared to the 1.9L diesel found in some international markets, the 6.6L Duramax is a much larger displacement engine designed for substantial work, prioritizing torque over fuel efficiency.
Suspension and Chassis
The Sierra 2500HD features a robust chassis designed to handle heavy loads. The front suspension utilizes an independent torsion bar setup with double wishbones, providing a comfortable ride while maintaining stability. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Ventilated disc brakes are used on all four wheels, providing ample stopping power. The truck’s steering system is a hydraulic power steering setup, offering a direct and responsive feel. The standard tire sizes range from 17 to 20 inches, depending on the trim level and options selected.
Legacy and Impact
The GMC Sierra 2500HD, and specifically the Duramax diesel variants, have established a strong reputation for reliability and capability in the North American market. These trucks are commonly used in a variety of applications, including construction, agriculture, and recreational towing. The ongoing development of the Duramax engine and Allison transmission demonstrates GMC’s commitment to providing heavy-duty truck buyers with a powerful and dependable powertrain. The 2024 facelift continues this legacy, offering a modern and refined heavy-duty truck experience.
