The GMC Sierra 2500HD, in its fifth generation (GMTT1XX), received a significant refresh for the 2024 model year. This article focuses specifically on the Regular Cab Long Bed configuration equipped with the 6.6-liter V8 gasoline engine producing 401 horsepower, paired with a 10-speed automatic transmission. Introduced in 2023 with the facelift, this variant represents a work-focused iteration of the Sierra 2500HD lineup, prioritizing capability and durability over luxury appointments. It serves as a robust option for commercial users and individuals requiring substantial towing and hauling capacity.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD V (GMTT1XX, facelift 2024) Regular Cab Long Bed |
| Type (Engine) | 6.6 V8 (401 Hp) Automatic |
| Start of production | 2023 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7 kg/Hp, 142.6 Hp/tonne |
| Weight-to-torque ratio | 4.5 kg/Nm, 223.6 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 |
| 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 | 2813 kg (6201.6 lbs) |
| Max. weight | 4536 kg (10000.17 lbs) |
| Max load | 1723 kg (3798.56 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 | 6002 mm (236.3 in) |
| Width including mirrors | 2076 mm (81.73 in) |
| Height | 2030 mm (79.92 in) |
| Wheelbase | 3595 mm (141.54 in) |
| Front track | 1731 mm (68.15 in) |
| Rear (Back) track | 1736 mm (68.35 in) |
| Ride height (ground clearance) | 259 mm (10.2 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, 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 | 245/75 R17; 265/70 R17; 275/70 R18; 275/65 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
INTRODUCTION
The 2024 GMC Sierra 2500HD Regular Cab Long Bed with the 6.6L V8 and 10-speed automatic represents a core offering within the heavy-duty truck segment. Built on the GMTT1XX platform, this configuration is designed for customers who prioritize functionality and towing capacity over luxury features. The Regular Cab layout and long bed provide a practical solution for work applications, while the 6.6L V8 engine delivers substantial power and torque for demanding tasks. This variant slots into the lineup as a step up from the base diesel option, offering a gasoline-powered alternative with comparable performance characteristics.
Powertrain & Engine Architecture
At the heart of this Sierra 2500HD lies the L8T 6.6-liter naturally aspirated V8 engine. This engine utilizes direct fuel injection, a proven technology for maximizing power and efficiency. The overhead valve (OHV) valvetrain contributes to its robust and reliable design. The engine produces 401 horsepower at 5200 rpm and 629 lb-ft of torque at 4000 rpm. This torque output is crucial for heavy towing and hauling. The engine is paired with a 10-speed Allison automatic transmission, a heavy-duty unit designed to handle the substantial power and torque of the V8. This transmission features electronically controlled shifts and is optimized for both on-road driving and demanding work conditions. The 10-speed configuration allows for closer gear ratios, improving both acceleration and fuel efficiency compared to older transmission designs.
Driving Characteristics
The 6.6L V8 and 10-speed automatic combination delivers a confident and capable driving experience. While not as refined as some of the newer turbocharged engines, the V8 provides a linear power delivery that is well-suited for towing and hauling. The 10-speed transmission effectively manages the engine’s powerband, providing ample torque in lower gears for starting heavy loads and maintaining speed on inclines. Compared to the diesel variants, the gasoline V8 offers a slightly quieter and smoother driving experience, although it may not match the diesel’s ultimate towing capacity. The Regular Cab configuration, while offering limited passenger space, contributes to a more nimble feel compared to the larger Crew Cab models.
Equipment & Trim Levels
The Sierra 2500HD Regular Cab Long Bed with the 6.6L V8 typically comes standard with a functional, work-oriented interior. Standard features generally include a basic infotainment system with a touchscreen display, Bluetooth connectivity, and a rearview camera. The interior upholstery is typically vinyl or cloth, designed for durability and ease of cleaning. Optional extras often include upgraded infotainment systems with larger screens, navigation, and Apple CarPlay/Android Auto compatibility. Other available options might include power windows and locks, keyless entry, and a basic sound system upgrade. The focus of this trim level is on providing essential features for work applications, rather than luxury amenities.
Chassis & Braking
The Sierra 2500HD features a robust chassis designed to withstand heavy loads and demanding conditions. The front suspension utilizes an independent torsion bar and double wishbone setup, providing a comfortable ride and good handling characteristics. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, with larger rotors at the front (355×40 mm) compared to the rear (360×34 mm). An Anti-lock Braking System (ABS) is standard equipment. The steering system utilizes a cone worm with recirculation balls, providing a direct and responsive feel.
Market Reception & Comparison
Critics generally view the 6.6L V8-powered Sierra 2500HD as a capable and reliable work truck. While the diesel variants often receive more attention for their ultimate towing capacity and fuel efficiency, the gasoline V8 offers a more affordable entry point into the heavy-duty truck segment. Fuel economy is typically lower than the diesel options, but the V8 provides a simpler and potentially less expensive maintenance profile. Compared to competitors like the Ford F-250 and Ram 2500 with comparable gasoline engines, the Sierra 2500HD offers a competitive combination of power, capability, and value.
Legacy
The 6.6L V8 engine has a long-standing reputation for reliability and durability within the GMC and Chevrolet truck lineups. While newer engine technologies are emerging, the L8T engine continues to be a popular choice for customers who prioritize simplicity and proven performance. In the used car market, Sierra 2500HD models equipped with this powertrain are generally well-regarded for their longevity and ability to withstand heavy use. Proper maintenance, including regular oil changes and fluid checks, is crucial for ensuring the long-term reliability of this powertrain.
