The GMC Sierra 3500HD, specifically the Crew Cab Long Bed configuration powered by the 6.6-liter Duramax Turbo Diesel V8 engine producing 470 horsepower, represents the pinnacle of GMC’s heavy-duty truck offerings as of the 2024 model year. This variant, part of the GMTT1XX generation and benefitting from a 2024 facelift, is designed for demanding tasks such as heavy towing and hauling. It occupies the top tier of the Sierra 3500HD lineup, appealing to customers requiring maximum capability and a refined driving experience. The “SRW” designation indicates a standard rear wheel drive configuration, though four-wheel drive is available as an option.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD V (GMTT1XX, facelift 2024) Crew Cab Long Bed |
| Type (Engine) | 6.6 Duramax TD V8 (470 Hp) SRW Automatic |
| Start of production | 2024 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.3 kg/Hp, 136.4 Hp/tonne |
| Weight-to-torque ratio | 2.6 kg/Nm, 383.6 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 | 3446 kg (7597.13 lbs.) |
| Max. weight | 5398 kg (11900.55 lbs.) |
| Max load | 1952 kg (4303.42 lbs.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 9072 kg (20000.34 lbs.) |
| Length | 6776 mm (266.77 in.) |
| Width including mirrors | 2079 mm (81.85 in.) |
| Height | 2049 mm (80.67 in.) |
| Wheelbase | 4369 mm (172.01 in.) |
| Front track | 1731 mm (68.15 in.) |
| Rear (Back) track | 1736 mm (68.35 in.) |
| Ride height (ground clearance) | 283 mm (11.14 in.) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine (ICE) drives the rear wheels. |
| 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 Crew Cab Long Bed with the 6.6L Duramax diesel and Allison automatic transmission is a heavy-duty pickup truck engineered for serious work. Building upon the GMTT1XX platform, which debuted in 2020, the 2024 model year represents a significant refresh, incorporating updated styling, enhanced technology, and refinements to the already capable powertrain. This particular configuration is positioned as a premium offering within the Sierra 3500HD range, targeting buyers who prioritize towing capacity, payload, and a comfortable cabin for long distances. It directly competes with trucks like the Ford F-350 Super Duty and Ram 3500.
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD lies the L5P 6.6-liter Duramax turbocharged diesel engine. This engine is a pushrod (OHV) V8, a design choice favored for its compact size and robust low-end torque. The engine utilizes a high-pressure common rail direct fuel injection system, delivering fuel directly into the cylinders at extremely high pressures for optimized combustion. The turbocharger, coupled with an intercooler, forces more air into the engine, boosting power and efficiency. The 16:1 compression ratio is typical for diesel engines, contributing to their inherent efficiency. The Allison 10-speed automatic transmission is specifically tuned to handle the immense torque output of the Duramax engine. This transmission features electronically controlled shifts and a robust internal design for durability. The transmission’s gear ratios are optimized for both towing and highway cruising, providing strong acceleration and efficient operation.
Driving Characteristics
The combination of the 470 horsepower and 975 lb-ft of torque delivered by the Duramax engine and the 10-speed Allison transmission results in a driving experience that is both powerful and surprisingly refined. While not designed for sporty handling, the Sierra 3500HD excels at its intended purpose: moving heavy loads. The 10-speed transmission allows the engine to stay within its optimal power band, even when towing at highway speeds. Compared to lower-output gasoline engine options in the Sierra 3500HD lineup, this diesel variant offers significantly more torque, making it far more capable for demanding tasks. Compared to the 6.6L gasoline engine, the Duramax provides a smoother power delivery and superior fuel economy when towing. The rear-wheel-drive configuration provides a traditional truck feel, while the available four-wheel-drive system enhances traction in challenging conditions.
Equipment & Trim Levels
The Crew Cab Long Bed configuration offers a spacious interior with seating for five passengers. Standard features typically include a user-friendly infotainment system with a touchscreen display, Apple CarPlay and Android Auto compatibility, and a premium sound system. Higher trim levels add features such as leather upholstery, heated and ventilated front seats, a power-adjustable steering column, and advanced safety technologies like adaptive cruise control and lane departure warning. The Long Bed configuration provides ample cargo space, while the Crew Cab offers generous passenger room. Optional extras include a sunroof, a rear-seat entertainment system, and a variety of towing packages.
Chassis & Braking
The Sierra 3500HD features a heavy-duty chassis designed to withstand the stresses of heavy towing and hauling. The front suspension utilizes an independent torsion bar and double wishbone setup, providing a comfortable ride and stable handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by ventilated disc brakes at all four corners, providing ample stopping power. The ABS (Anti-lock Braking System) helps maintain control during emergency braking situations. The hydraulic power steering system provides precise and responsive steering feel.
Market Reception & Comparison
The GMC Sierra 3500HD with the Duramax diesel engine has consistently received positive reviews from automotive critics. It is praised for its powerful engine, smooth transmission, comfortable ride, and impressive towing capacity. Compared to the gasoline-powered Sierra 3500HD models, the Duramax diesel offers superior fuel economy when towing heavy loads, although the initial purchase price is higher. The Sierra 3500HD competes directly with the Ford F-350 Super Duty and Ram 3500, each offering similar capabilities. The GMC often stands out for its refined interior and available technology features.
Legacy
The Duramax diesel engine has established a strong reputation for reliability and longevity. The L5P engine, in particular, has proven to be a durable and dependable powerplant. Well-maintained examples of the 2024 Sierra 3500HD are expected to hold their value well in the used car market. The Allison 10-speed automatic transmission is also known for its robustness and smooth operation. The combination of these two components makes this Sierra 3500HD a desirable truck for buyers seeking a capable and long-lasting heavy-duty pickup.
