The GMC Sierra 3500HD, in its fifth generation (GMTT1XX), received a significant facelift for the 2024 model year. This iteration represents GMC’s heavy-duty pickup truck offering, positioned above the Sierra 1500 and designed for demanding tasks like towing and hauling. The Double Cab Long Bed configuration, paired with the 6.6-liter Duramax Turbo-Diesel V8 engine producing 470 horsepower and utilizing a ten-speed Allison automatic transmission, represents a premium offering within the 3500HD lineup, geared towards professional users and those requiring substantial capability. This particular variant, often referred to as a “DRW” (Dual Rear Wheel) model, further enhances its towing and payload capacity.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD V (GMTT1XX, facelift 2024) Double 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 | 7.6 kg/Hp, 132.1 Hp/tonne |
| Weight-to-torque ratio | 2.7 kg/Nm, 371.5 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 | 3559 kg (7846.25 lbs.) |
| Max. weight | 6350 kg (13999.35 lbs.) |
| Max load | 2791 kg (6153.1 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 | 6534 mm (257.24 in.) |
| Width including mirrors | 2457 mm (96.73 in.) |
| Height | 2037 mm (80.2 in.) |
| Wheelbase | 4127 mm (162.48 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 | 275/70 R18; 275/65 R20 |
| Wheel rims size | 8J x 18; 8.5J x 20 |
INTRODUCTION
The 2024 GMC Sierra 3500HD Double Cab Long Bed with the 6.6L Duramax diesel and Allison automatic represents the pinnacle of GMC’s heavy-duty truck capabilities. Built on the GMTT1XX platform, this facelifted model builds upon the strengths of its predecessor, offering increased refinement, technology, and towing capacity. The DRW configuration, with its dual rear wheels, is specifically designed for owners who regularly tow extremely heavy loads, such as large trailers, equipment, or livestock. This variant sits at the top end of the 3500HD range, offering a significant step up in capability compared to the standard single-rear-wheel models and gasoline-powered options.
Powertrain & Engine Architecture
The heart of this Sierra 3500HD is the L5P 6.6-liter Duramax turbocharged diesel V8 engine. This engine is a cornerstone of GMC’s heavy-duty lineup, known for its robust construction and impressive torque output. The L5P utilizes a direct injection common rail fuel system, delivering fuel at extremely high pressures for efficient combustion. The engine features an overhead valve (OHV) valvetrain, a design choice favored for its durability and low-end torque characteristics. A single variable geometry turbocharger, coupled with an intercooler, provides optimal boost across the engine’s operating range. The ten-speed Allison automatic transmission is specifically calibrated to handle the immense torque produced by the Duramax engine. This transmission features electronically controlled shifts and a robust internal design, ensuring smooth and reliable operation even under heavy loads.
Driving Characteristics
The combination of the 470 horsepower and 1322 lb-ft of torque delivered by the Duramax engine and the ten-speed Allison transmission results in a driving experience focused on effortless power and control. While not designed for outright speed, this Sierra 3500HD excels at accelerating even when heavily loaded. The ten-speed transmission allows the engine to remain in its optimal power band, providing strong acceleration and minimizing the need for frequent downshifts. Compared to the gasoline engine options, the Duramax offers significantly more low-end torque, making it ideal for towing and hauling. The DRW configuration enhances stability when towing, reducing sway and providing a more confident driving experience. The ride quality, while firm due to the heavy-duty suspension, is surprisingly comfortable, especially when unladen.
Equipment & Trim Levels
The 2024 Sierra 3500HD Double Cab Long Bed with the Duramax engine is typically offered in higher trim levels, such as Denali or AT4. These trims include a wealth of standard features, including leather upholstery, heated and ventilated front seats, a premium sound system, and advanced safety technologies. Standard equipment also includes a large infotainment touchscreen with Apple CarPlay and Android Auto compatibility, as well as a suite of driver-assistance features like automatic emergency braking and lane departure warning. Optional extras include a power sunroof, a rear-seat entertainment system, and a bed-view camera. The interior design emphasizes functionality and durability, with high-quality materials and intuitive controls.
Chassis & Braking
The Sierra 3500HD’s chassis is designed to withstand the stresses of heavy-duty use. It features a fully boxed frame constructed from high-strength steel. The front suspension utilizes an independent torsion bar and double wishbone design, providing a comfortable ride and precise handling. The rear suspension employs a rigid axle with leaf springs, optimized for load-carrying capacity. The braking system consists of ventilated discs at all four wheels, providing ample stopping power even when towing. An Anti-lock Braking System (ABS) is standard, enhancing safety and control during emergency braking situations. The steering system utilizes a hydraulic power steering system, providing responsive and precise steering feel.
Market Reception & Comparison
The 2024 GMC Sierra 3500HD with the Duramax diesel engine has been well-received by critics and consumers alike. It is consistently praised for its powerful engine, smooth transmission, and impressive towing capacity. Compared to its competitors, such as the Ford Super Duty and Ram 3500, the Sierra 3500HD offers a compelling combination of capability, refinement, and technology. While the Duramax engine typically delivers slightly lower fuel economy than the gasoline engine options, its superior torque and towing capacity make it the preferred choice for those who regularly haul heavy loads. Reliability has generally been 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 itself as a benchmark for reliability and durability in the heavy-duty truck segment. The L5P version, found in the 2024 Sierra 3500HD, continues this legacy, offering years of dependable service with proper maintenance. On the used car market, these trucks hold their value well due to their reputation for capability and longevity. The ten-speed Allison transmission has also proven to be a robust and reliable component, further enhancing the long-term appeal of this powertrain combination. As emissions regulations continue to evolve, the Duramax engine is likely to remain a key component of GMC’s heavy-duty truck lineup for years to come.
