The GMC Sierra 2500HD V (GMTT1XX) Crew Cab Standard Bed, equipped with the 6.6-liter V8 engine producing 401 horsepower, represents a significant offering in the heavy-duty pickup truck segment. Produced from 2020 to 2023, this variant occupied a strong position within the Sierra 2500HD lineup, catering to buyers needing substantial towing and hauling capabilities combined with a degree of comfort and refinement. It was part of the GMTT1XX generation, a platform designed to enhance strength, technology, and overall usability compared to its predecessors.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD V (GMTT1XX) Crew Cab Standard Bed |
| Type (Engine) | 6.6 V8 (401 Hp) Automatic |
| Start of production | 2020 year |
| End of production | 2023 year |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.4 kg/Hp, 135.3 Hp/tonne |
| Weight-to-torque ratio | 4.7 kg/Nm, 212.3 Nm/tonne |
| Power | 401 Hp @ 5200 rpm |
| Torque | 629 Nm @ 4000 rpm, 463.93 lb.-ft. @ 4000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L8T |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103.25 mm, 4.06 in. |
| Piston Stroke | 98 mm, 3.86 in. |
| Compression ratio | 10.8:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Direct injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV, VVT |
| Engine oil capacity | 7.6 l, 8.03 US qt | 6.69 UK qt |
| Coolant | 14.6 l, 15.43 US qt | 12.85 UK qt |
| Kerb Weight | 2963 kg, 6532.3 lbs. |
| Max. weight | 4604 kg, 10150.08 lbs. |
| Max load | 1641 kg, 3617.79 lbs. |
| Fuel tank capacity | 136 l, 35.93 US gal | 29.92 UK gal |
| Permitted trailer load with brakes (12%) | 6577 kg, 14499.8 lbs. |
| Length | 6352 mm, 250.08 in. |
| Width including mirrors | 2079 mm, 81.85 in. |
| Height | 2027 mm, 79.8 in. |
| Wheelbase | 4037 mm, 158.94 in. |
| Front track | 1731 mm, 68.15 in. |
| Rear (Back) track | 1736 mm, 68.35 in. |
| Ride height (ground clearance) | 257 mm, 10.12 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 | 6 gears, automatic transmission Hydra-Matic |
| Front suspension | Coil spring, Double wishbone, Transverse stabilizer |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 355×40 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 | 265/70 R17; 245/75 R17; 275/70 R18 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
Powertrain & Engine Architecture
At the heart of the Sierra 2500HD is the 6.6-liter L8T V8 gasoline engine. This engine is a naturally aspirated, overhead valve (OHV) design featuring variable valve timing (VVT). The L8T utilizes direct fuel injection, contributing to improved efficiency and power output. The engine produces 401 horsepower at 5200 rpm and 464 lb-ft of torque at 4000 rpm. This power is delivered through a six-speed Hydra-Matic automatic transmission, specifically tuned for heavy-duty applications. The transmission is designed to handle the substantial torque output of the engine and provide smooth, reliable shifting even under heavy loads. The engine’s longitudinal mounting and rear-wheel-drive configuration are standard for this class of truck.
Driving Characteristics
The 6.6L V8 and six-speed automatic combination in the Sierra 2500HD delivers a balance of power and usability. While not as quick as some of the diesel-powered variants, the gasoline engine provides ample power for everyday driving and towing. The automatic transmission is well-matched to the engine’s characteristics, offering smooth shifts and a predictable driving experience. The gear ratios are optimized for towing, providing strong low-end torque. Compared to a manual transmission, the automatic offers convenience, especially in stop-and-go traffic or when navigating challenging terrain with a trailer. However, it may not offer the same level of engine braking control as a manual. The overall driving experience is characterized by a comfortable ride, thanks to the truck’s robust suspension, and a confident feel when hauling heavy loads.
Equipment & Trim Levels
The Crew Cab Standard Bed configuration of the Sierra 2500HD typically came standard with features like air conditioning, power windows and locks, a basic infotainment system with a touchscreen display, and a rearview camera. Higher trim levels, such as the SLT and Denali, added features like leather upholstery, heated and ventilated seats, a premium sound system, and advanced safety technologies. Optional extras included a sunroof, navigation system, and various towing packages. The interior design focused on durability and functionality, with comfortable seating and a user-friendly layout. The standard bed length provided a good balance between cargo capacity and maneuverability.
Chassis & Braking
The Sierra 2500HD features a robust chassis designed to withstand the stresses of heavy-duty use. The front suspension utilizes a coil spring, double wishbone setup with a transverse stabilizer bar, while the rear suspension employs a traditional leaf spring design. This configuration provides a comfortable ride and excellent load-carrying capacity. Braking duties are handled by ventilated discs at all four corners, providing ample stopping power. The front brakes measure 355×40 mm, while the rear brakes are 360×34 mm. An anti-lock braking system (ABS) is standard, enhancing safety and control. The steering system is a cone worm with recirculation balls, providing precise and responsive handling.
Market Reception & Comparison
The GMC Sierra 2500HD with the 6.6L V8 and automatic transmission was generally well-received by critics and consumers. It was praised for its strong towing capacity, comfortable ride, and user-friendly features. However, it was often noted that the gasoline engine offered lower fuel economy compared to the available diesel options. Compared to the Duramax diesel engine, the 6.6L V8 provided less torque and lower fuel efficiency, but it was also less expensive to purchase and maintain. The gasoline engine was a popular choice for buyers who did not require the maximum towing capacity of the diesel and preferred the lower upfront cost.
Legacy
The L8T 6.6L V8 engine, paired with the Hydra-Matic automatic transmission, has proven to be a relatively reliable powertrain in the Sierra 2500HD. While not without its potential issues (such as occasional Active Fuel Management problems), it generally provides years of dependable service with proper maintenance. In the used car market, these trucks remain popular choices for buyers seeking a capable and affordable heavy-duty pickup. The combination of gasoline power, automatic convenience, and a spacious Crew Cab configuration makes this variant a versatile and practical option for a wide range of applications. Its continued presence in the used market is a testament to its durability and overall value.
