The GMC Sierra 3500HD, specifically the 2024 model year facelift featuring the Crew Cab Long Bed configuration with the 6.6-liter Duramax Turbo Diesel V8 engine producing 470 horsepower, represents GMC’s heavy-duty pickup truck offering. Introduced as part of the GMTT1XX generation, this variant caters to buyers requiring substantial towing and hauling capabilities. The 2024 refresh brought updated styling and technology, building upon the already robust foundation of the Sierra HD line. This particular configuration, with its dual rear wheels (DRW), is geared towards professional users and those needing maximum payload and towing capacity.
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) DRW 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 | 7.7 kg/Hp, 130.5 Hp/tonne |
| Weight-to-torque ratio | 2.7 kg/Nm, 367.1 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 | 3601 kg (7938.85 lbs.) |
| Max. weight | 6350 kg (13999.35 lbs.) |
| Max load | 2749 kg (6060.51 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 | 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) 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, 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 Duramax diesel and Allison automatic transmission is a heavy-duty pickup truck designed for demanding tasks. Positioned as a premium offering within the Sierra 3500HD lineup, this variant sits at the top end of capability, aimed at customers who frequently tow large trailers, haul heavy loads, or require a robust work truck. The DRW (Dual Rear Wheel) configuration further enhances stability and payload capacity. The GMTT1XX platform, updated for 2024, provides a solid foundation for this powerful truck, incorporating improvements in technology, comfort, and safety.
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD lies the L5P 6.6-liter Duramax turbocharged diesel V8 engine. This engine is a cornerstone of GMC’s heavy-duty lineup, known for its durability and impressive torque output. The L5P utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The engine features an overhead valve (OHV) valvetrain, a design choice prioritizing low-end torque and reliability. A single variable geometry turbocharger with an intercooler provides forced induction, boosting power and efficiency. The engine’s 16:1 compression ratio contributes to its efficiency and power. Paired with the engine is the Allison 10-speed automatic transmission, a heavy-duty unit specifically designed to handle the immense torque produced by the Duramax diesel. This transmission features electronically controlled shifts and a lock-up torque converter for improved fuel economy and responsiveness.
Driving Characteristics
The combination of the 470 horsepower and 1322 lb-ft of torque delivered by the Duramax engine and the 10-speed Allison transmission results in a driving experience focused on effortless power and towing capability. While not designed for sporty acceleration, the Sierra 3500HD provides ample power for merging onto highways and maintaining speed even when heavily loaded. The 10-speed transmission allows the engine to operate within its optimal power band more frequently, improving both performance and fuel economy. Compared to gasoline-powered Sierra 3500HD models, the diesel offers significantly more torque at lower RPMs, making it ideal for towing. Compared to other diesel variants within the Sierra lineup, this 470 hp version represents the highest output, offering a noticeable performance advantage over lower-powered options. The DRW configuration contributes to a more stable and controlled driving experience, particularly when towing or hauling heavy loads.
Equipment & Trim Levels
The Crew Cab Long Bed configuration provides 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 audio 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 2024 facelift brought updated interior materials and a redesigned dashboard layout. Optional extras include a rear-seat entertainment system, a sunroof, and a bed liner.
Chassis & Braking
The Sierra 3500HD features a robust chassis designed to withstand heavy loads. The front suspension utilizes an independent torsion bar setup with double wishbones, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. The DRW configuration adds significant stability. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) is standard. The steering system utilizes a cone worm and recirculation balls setup, offering precise control and feedback.
Market Reception & Comparison
The GMC Sierra 3500HD with the Duramax diesel engine consistently receives positive reviews for its towing capability, durability, and comfortable ride. Critics often praise the Allison transmission for its smooth shifting and reliability. Compared to competitors like the Ford Super Duty and Ram Heavy Duty, the Sierra 3500HD is often positioned as a more refined and luxurious option. Fuel economy, while improved with the 10-speed transmission, remains a consideration for diesel trucks of this size. Reliability is generally considered good, although diesel engines can be more expensive to maintain than gasoline engines due to the complexity of the fuel injection system and emissions controls.
Legacy
The Duramax diesel engine has established a strong reputation for longevity and reliability. The L5P engine, in particular, has proven to be a durable and capable powerplant. In the used car market, Sierra 3500HD models equipped with the Duramax diesel and Allison transmission hold their value well due to their proven track record and high demand. Proper maintenance, including regular oil changes and fuel filter replacements, is crucial for ensuring the long-term reliability of this powertrain. The 2024 facelift is expected to further enhance the Sierra 3500HD’s appeal and maintain its position as a leading heavy-duty pickup truck.
