The GMC Sierra 3500HD, specifically the 2024 model year facelift in its Regular Cab Long Bed configuration with the 6.6-liter V8 engine producing 401 horsepower, represents GMC’s heavy-duty pickup truck offering. Introduced as part of the GMTT1XX generation, this variant caters to buyers needing substantial towing and payload capacity. The 2024 refresh brought updated styling and technology, building upon the already robust foundation of the Sierra HD line. This particular configuration, combining the powerful V8 with a four-wheel-drive system and an Allison ten-speed automatic transmission, positions itself as a workhorse capable of handling demanding tasks while offering a degree of refinement for daily driving.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD V (GMTT1XX, facelift 2024) Regular Cab Long Bed |
| Type (Engine) | 6.6 V8 (401 Hp) 4WD SRW Automatic |
| Start of production | 2024 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.5 kg/Hp, 132.5 Hp/tonne |
| Weight-to-torque ratio | 4.8 kg/Nm, 207.9 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 | 3026 kg (6671.19 lbs) |
| Max. weight | 5125 kg (11298.69 lbs) |
| Max load | 2099 kg (4627.5 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 | 2056 mm (80.94 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) | 285 mm (11.22 in) |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| 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 | 275/70 R18; 275/65 R20 |
| Wheel rims size | 8J x 18; 8.5J x 20 |
Introduction
The 2024 GMC Sierra 3500HD Regular Cab Long Bed with the 6.6L V8 engine and 4WD represents a significant offering in the heavy-duty truck segment. Built on the GMTT1XX platform, this truck is designed for demanding work applications, prioritizing towing capacity, payload, and durability. The Regular Cab configuration, paired with the long bed, caters to customers who prioritize functionality over passenger space. The facelift for 2024 included exterior styling updates and interior technology enhancements, aiming to improve the overall ownership experience. This variant sits towards the upper end of the Sierra 3500HD lineup in terms of capability, though it isn’t the most luxurious trim available.
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD lies the 6.6-liter L8T V8 gasoline engine. This engine utilizes direct fuel injection, a technology that improves efficiency and power output by injecting fuel directly into the combustion chamber. The engine features an overhead valve (OHV) valvetrain, a design known for its simplicity and reliability. The 10.8:1 compression ratio contributes to the engine’s power delivery. The engine is mated to a ten-speed Allison automatic transmission, a robust unit specifically designed for heavy-duty applications. This transmission provides a wide range of gear ratios, optimizing both towing performance and fuel efficiency. The Allison transmission is known for its durability and smooth shifting characteristics. The engine’s longitudinal mounting and rear-wheel-drive bias, coupled with the electronically controlled four-wheel-drive system, provide excellent traction in various conditions.
Driving Characteristics
The 401 horsepower and 463.93 lb-ft of torque delivered by the 6.6L V8, combined with the ten-speed Allison transmission, provide a strong and capable driving experience. While not as quick as lighter-duty trucks, the Sierra 3500HD excels in situations requiring substantial pulling power. The ten-speed transmission allows the engine to stay within its optimal power band, even when towing heavy loads. Compared to potential diesel engine options in the lineup, this gasoline V8 offers a more responsive feel and a quieter cabin experience, though it sacrifices some low-end torque and fuel economy. The four-wheel-drive system provides enhanced traction on slippery surfaces, making it suitable for both on-road and off-road use. The ride quality, while firm due to the heavy-duty suspension, is generally comfortable for a truck of this size.
Equipment & Trim Levels
The 2024 Sierra 3500HD Regular Cab Long Bed 6.6 V8 4WD typically comes standard with features such as air conditioning, a basic infotainment system with a touchscreen display, and power windows and locks. Higher trim levels, such as the SLE or Denali, add features like leather upholstery, heated and ventilated seats, a premium sound system, and advanced safety technologies. Optional extras for this variant could include a trailer brake controller, a bed liner, and various appearance packages. The interior design is functional and durable, prioritizing practicality over luxury in the base configurations.
Chassis & Braking
The Sierra 3500HD utilizes a robust chassis designed to withstand heavy loads and demanding conditions. The front suspension features an independent torsion bar setup with double wishbones, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, known for its durability and load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, 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 during emergency braking situations. The steering system utilizes a cone worm and recirculation ball mechanism, providing precise and responsive steering feel.
Market Reception & Comparison
The 2024 GMC Sierra 3500HD with the 6.6L V8 engine received generally positive reviews, with critics praising its towing capacity, robust construction, and comfortable ride. Compared to the diesel engine options, the gasoline V8 was often seen as a more affordable and accessible entry point into the heavy-duty truck market. However, the diesel engines offered superior fuel economy and torque, making them more suitable for customers who frequently tow heavy loads. The gasoline engine’s fuel economy was considered adequate for occasional towing and daily driving, but it lagged behind the diesel alternatives. Reliability reports generally indicated good long-term durability for the 6.6L V8 and Allison transmission combination.
Legacy
The GMTT1XX generation Sierra 3500HD, and specifically the 6.6L V8/Allison automatic powertrain, has established a reputation for reliability and durability. These trucks continue to be popular in the used car market, particularly among buyers seeking a capable and affordable heavy-duty pickup. The Allison transmission is highly regarded for its longevity, and the 6.6L V8 engine is known for its relatively simple design, making it easier and less expensive to maintain compared to more complex engines. As these trucks age, proper maintenance and regular servicing are crucial to ensure continued reliability and performance. The combination of power, capability, and relative affordability has cemented this variant’s place as a workhorse in the American trucking landscape.
