The GMC Sierra 3500HD, in its fifth generation (GMTT1XX), received a significant refresh for the 2024 model year. This iteration continues GMC’s tradition of offering a robust and capable heavy-duty pickup truck aimed at demanding tasks like towing and hauling. The Crew Cab Long Bed configuration, paired with the 6.6-liter V8 gasoline engine producing 401 horsepower, represents a popular choice for buyers needing a balance of power, space, and usability. This particular variant occupies a strong position in the lineup, offering substantial capability without the higher price point of the Duramax diesel options. Production began in late 2023 for the 2024 model year, building upon the foundation laid by the GMTT1XX platform introduced in 2020.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD V (GMTT1XX, facelift 2024) Crew Cab Long Bed |
| Type (Engine) | 6.6 V8 (401 Hp) DRW Automatic |
| Start of production | 2024 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 8.1 kg/Hp, 123 Hp/tonne |
| Weight-to-torque ratio | 5.2 kg/Nm, 192.9 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 | 3261 kg (7189.27 lbs) |
| Max. weight | 6350 kg (13999.35 lbs) |
| Max load | 3089 kg (6810.08 lbs) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 8255 kg (18199.16 lbs) |
| Length | 6776 mm (266.77 in) |
| Width including mirrors | 2457 mm (96.73 in) |
| Height | 2049 mm (80.67 in) |
| Wheelbase | 4369 mm (172.01 in) |
| Front track | 1731 mm (68.15 in) |
| Rear (Back) track | 1905 mm (75 in) |
| Ride height (ground clearance) | 264 mm (10.39 in) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine (ICE) |
| 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, 355×40 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | 235/80 R17; 235/80 R18 |
| Wheel rims size | 6.5J x 17; 8J x 18 |
Introduction
The 2024 GMC Sierra 3500HD Crew Cab Long Bed with the 6.6L V8 and automatic transmission is a heavy-duty pickup truck designed for serious work. It builds upon the GMTT1XX platform, which debuted in 2020, and benefits from the 2024 facelift that included updated styling and interior enhancements. This configuration is positioned as a strong all-around performer, offering a significant step up in towing and payload capacity compared to the Sierra 1500, while remaining more accessible than the diesel-powered 3500HD models. The Crew Cab configuration provides ample passenger space, making it suitable for both work and family use, while the long bed offers a generous cargo area.
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD is the 6.6-liter L8T V8 gasoline engine. This engine is a naturally aspirated, overhead valve (OHV) design featuring direct fuel injection. The direct injection system improves efficiency and power delivery by injecting fuel directly into the combustion chamber. The engine produces 401 horsepower at 5200 rpm and 629 lb-ft of torque at 4000 rpm. The engine’s robust construction and relatively simple design contribute to its reputation for reliability. The engine is mated to a heavy-duty 10-speed Allison automatic transmission. This transmission is known for its durability and smooth shifting, and its ten gears allow the engine to operate efficiently across a wide range of speeds and loads. The transmission is electronically controlled, optimizing shift points for power, fuel economy, and towing performance.
Driving Characteristics
The 6.6L V8 and 10-speed automatic combination delivers a confident driving experience, particularly when towing or hauling heavy loads. While not as fuel-efficient as the diesel options, the gasoline engine provides ample power for most tasks. The 10-speed transmission helps to keep the engine in its optimal power band, providing strong acceleration and responsive performance. Compared to the 6.6L Duramax diesel, this gasoline engine offers quicker acceleration at lower speeds, but lacks the diesel’s superior low-end torque and fuel economy. The gear ratios in the Allison transmission are well-suited for both highway cruising and demanding work conditions. The truck feels stable and planted, even when fully loaded, thanks to its heavy-duty suspension and robust chassis.
Equipment & Trim Levels
The 2024 Sierra 3500HD Crew Cab Long Bed 6.6L V8 typically comes standard with a comprehensive suite of features. These include a user-friendly infotainment system with a touchscreen display, Apple CarPlay and Android Auto compatibility, and a rearview camera. Higher trim levels, such as the Denali, add premium features like leather upholstery, heated and ventilated seats, a premium sound system, and advanced safety technologies. Available options include a power sunroof, a bed liner, and various towing packages. The interior design is functional and durable, with comfortable seating and intuitive controls. The Crew Cab configuration provides generous legroom for all passengers.
Chassis & Braking
The Sierra 3500HD features a fully boxed frame constructed from high-strength steel, providing a solid foundation for its heavy-duty capabilities. The front suspension utilizes an independent torsion bar and double wishbone design, while the rear suspension employs a traditional leaf spring setup. This combination provides a comfortable ride, even when the truck is unloaded, and offers excellent stability when towing or hauling. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) is standard, enhancing safety and control during emergency braking situations. The steering system is a hydraulic rack-and-pinion setup, offering precise and responsive steering feel.
Market Reception & Comparison
The 2024 GMC Sierra 3500HD with the 6.6L V8 has been generally well-received by critics and consumers alike. It’s praised for its strong towing and hauling capabilities, comfortable ride, and user-friendly features. Compared to the diesel-powered Sierra 3500HD, the gasoline engine offers a lower initial cost but sacrifices fuel economy and low-end torque. Against competitors like the Ford Super Duty and Ram 3500, the Sierra 3500HD holds its own, offering a compelling combination of power, capability, and refinement. Fuel economy is rated at approximately 14 mpg city and 17 mpg highway, which is typical for a heavy-duty pickup truck of this size and capability.
Legacy
The 6.6L gasoline V8 engine has proven to be a reliable and durable powertrain in the Sierra and Silverado HD trucks. While not as popular as the Duramax diesel, it remains a viable option for buyers who prioritize affordability and simplicity. The GMTT1XX platform has established itself as a capable and well-engineered foundation for the Sierra 3500HD. In the used car market, these trucks are generally sought after for their towing and hauling capabilities, and well-maintained examples tend to hold their value reasonably well. The Allison 10-speed automatic transmission is also known for its longevity and reliability, making this powertrain combination a solid choice for long-term ownership.
