The GMC Sierra 3500HD, in its fifth generation (GMTT1XX), received a significant facelift for the 2024 model year. This iteration continues GMC’s tradition of offering a heavy-duty pickup truck geared towards demanding tasks like towing and hauling. The Crew Cab Long Bed configuration, paired with the 6.6-liter Duramax Turbo Diesel V8 engine producing 470 horsepower and coupled with a 10-speed Allison automatic transmission and four-wheel drive (4WD) with a dual rear wheel (DRW) setup, represents a top-tier offering within the Sierra 3500HD lineup. This particular variant is positioned as a premium work truck and recreational vehicle hauler, catering to customers needing substantial capability and a comfortable cabin.
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) 4WD 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 | 8 kg/Hp, 125.7 Hp/tonne |
| Weight-to-torque ratio | 2.8 kg/Nm, 353.5 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 | 3740 kg (8245.29 lbs.) |
| Max. weight | 6350 kg (13999.35 lbs.) |
| Max load | 2610 kg (5754.07 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 | 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, 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 10-speed Allison automatic represents the pinnacle of GMC’s heavy-duty truck offerings. Built on the GMTT1XX platform, this truck is designed for owners who require substantial towing and payload capacity without sacrificing interior comfort. The facelifted 2024 model boasts updated styling, enhanced technology, and refinements to the Duramax engine for improved performance and efficiency. This configuration is a direct competitor to Ford’s Super Duty and Ram’s 3500 models, aiming to capture the segment of buyers who prioritize capability and a premium experience.
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 robust construction and impressive torque output. The L5P utilizes a cast iron block, aluminum cylinder heads, and a forged steel crankshaft. The engine employs a high-pressure common rail direct fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The turbocharger, coupled with an intercooler, provides increased air density for enhanced power. The overhead valve (OHV) valvetrain is a design choice prioritizing durability and low-end torque. The 10-speed Allison automatic transmission is specifically calibrated to handle the immense torque produced by the Duramax engine, providing smooth and efficient power delivery. This transmission features electronically controlled shifts and a tow/haul mode for optimized performance when towing heavy loads.
Driving Characteristics
The combination of the 470 horsepower and 1322 lb-ft of torque, coupled with the 10-speed Allison transmission, results in a driving experience that is both powerful and surprisingly refined. While not designed for outright speed, the Sierra 3500HD excels at accelerating with heavy loads. The 10-speed transmission keeps the engine within its optimal power band, providing strong acceleration even when towing near its maximum capacity. Compared to lower-output gasoline engine options, the Duramax diesel offers significantly more torque at lower RPMs, making it ideal for demanding tasks. Compared to older Duramax models, the 2024 version benefits from improved transmission tuning and engine management, resulting in smoother shifts and reduced engine noise. The dual rear wheel configuration enhances stability when towing and hauling heavy loads, providing a more confident driving experience.
Equipment & Trim Levels
The Crew Cab Long Bed configuration typically comes standard with a generous array of features. Interior appointments include comfortable cloth or leather seating, a user-friendly infotainment system with a large touchscreen display, and advanced safety technologies like automatic emergency braking and lane departure warning. Higher trim levels, such as Denali, add premium features like heated and ventilated seats, a premium audio system, and unique exterior styling cues. Optional extras include a power sunroof, a rear-seat entertainment system, and a variety of towing packages tailored to specific needs. The 2024 facelift brought updated interior materials and a redesigned dashboard layout, enhancing the overall cabin experience.
Chassis & Braking
The Sierra 3500HD features a robust chassis designed to withstand the stresses of heavy-duty use. The front suspension utilizes an independent torsion bar setup with double wishbones, providing a comfortable ride and precise handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power even when fully loaded. The anti-lock braking system (ABS) enhances safety by preventing wheel lockup during hard braking. The hydraulic power steering system provides responsive and precise steering control. The DRW setup significantly increases the truck’s stability and braking performance when towing heavy trailers.
Market Reception & Comparison
The 2024 GMC Sierra 3500HD has been well-received by critics and consumers alike. Reviewers praise the truck’s powerful Duramax engine, smooth-shifting Allison transmission, and comfortable interior. Compared to gasoline-powered Sierra 3500HD models, the Duramax diesel offers superior towing capacity and fuel economy, especially when hauling heavy loads. However, the diesel engine comes with a higher initial cost and potentially higher maintenance expenses. Compared to competitors like the Ford Super Duty and Ram 3500, the Sierra 3500HD offers a compelling combination of capability, comfort, and technology. Fuel economy is competitive within the heavy-duty truck segment, averaging around 18-20 mpg on the highway.
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, capable of accumulating hundreds of thousands of miles with proper maintenance. On the used car market, Sierra 3500HD models equipped with the Duramax diesel and Allison transmission command a premium price due to their proven capability and reliability. The 2024 facelifted model is expected to further enhance the Sierra 3500HD’s reputation as a top-tier heavy-duty truck, ensuring its continued success in the competitive pickup truck market.
