The Chevrolet Silverado 3500 HD IV (T1XX) Double Cab Long Bed, equipped with the 6.6-liter Duramax V8 engine producing 445 horsepower, represents a significant offering in the heavy-duty pickup truck segment. Produced from 2020 through 2023, this configuration occupied a prominent position within the fourth generation (T1XX) Silverado HD lineup, catering to buyers requiring substantial towing and hauling capabilities combined with a degree of interior comfort. This particular variant, featuring a four-wheel-drive (4WD) system and a ten-speed Allison automatic transmission, was aimed at both commercial users and private owners needing a robust and reliable work truck.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD IV (T1XX) Double Cab Long Bed |
| Type (Engine) | 6.6 Duramax V8 (445 Hp) 4WD SRW Automatic |
| Start of production | 2020 |
| End of production | 2023 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 8.1 kg/Hp, 123.2 Hp/tonne |
| Weight-to-torque ratio | 2.9 kg/Nm, 341.6 Nm/tonne |
| Power | 445 Hp @ 2800 rpm |
| Power per litre | 67.4 Hp/l |
| Torque | 1234 Nm @ 1600 rpm (910.15 lb.-ft. @ 1600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax 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 | 29.1 l (30.75 US qt | 25.6 UK qt) |
| Kerb Weight | 3612 kg (7963.1 lbs.) |
| Max. weight | 5511 kg (12149.68 lbs.) |
| Max load | 1899 kg (4186.58 lbs.) |
| Trunk (boot) space – maximum | 2364 l (83.48 cu. ft.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 9620 kg (21208.47 lbs.) |
| Length | 6514 mm (256.46 in.) |
| Width including mirrors | 2079 mm (81.85 in.) |
| Height | 2054 mm (80.87 in.) |
| Wheelbase | 4127 mm (162.48 in.) |
| Front track | 1731 mm (68.15 in.) |
| Rear (Back) track | 1736 mm (68.35 in.) |
| Ride height (ground clearance) | 284 mm (11.18 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, 360×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | 265/70 R17; 245/75 R17; 265/70 R18 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
INTRODUCTION
The 2020-2023 Chevrolet Silverado 3500 HD Double Cab Long Bed with the 6.6L Duramax diesel and Allison automatic transmission represents a workhorse in the American heavy-duty truck market. Built on the T1XX platform, this generation Silverado HD aimed to improve upon its predecessor with enhanced technology, increased capability, and a more refined interior. The Double Cab configuration offered a balance between passenger space and bed length, making it suitable for both work crews and families. This specific powertrain combination was positioned as a premium offering, sitting above the gasoline-powered options and providing a significant step up in towing and hauling capacity.
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD lies the Duramax L5P 6.6-liter V8 diesel engine. This engine is a turbocharged, overhead valve (OHV) design, known for its durability and strong low-end torque. The L5P utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressures for efficient combustion. A variable geometry turbocharger (VGT) and intercooler further enhance performance and reduce emissions. The engine produces 445 horsepower at 2800 rpm and a massive 910 lb-ft (1234 Nm) of torque at 1600 rpm. This torque output is crucial for heavy towing and hauling. Paired with the Duramax is the Allison 10-speed automatic transmission. This transmission is specifically designed to handle the high torque output of the diesel engine and provides smooth, efficient shifting. The ten-speed configuration allows for closer gear ratios, optimizing engine performance for both highway cruising and demanding work conditions.
Driving Characteristics
The Silverado 3500 HD 6.6L Duramax with the Allison 10-speed delivers a driving experience focused on capability and control. While not a sports truck, the ample torque provides strong acceleration, even when heavily loaded. The Allison transmission shifts smoothly and intelligently, keeping the engine in its optimal power band. The 10-speed design allows for a wider range of gear ratios compared to older transmissions, improving both fuel economy and towing performance. Compared to the gasoline-powered Silverado 3500 HD models, the Duramax diesel offers significantly more torque, making it far superior for demanding tasks. Compared to earlier Duramax engines paired with 6-speed transmissions, the 10-speed Allison provides more refined shifting and improved fuel efficiency. The ride quality, even unladen, is relatively comfortable for a heavy-duty truck, thanks to the well-tuned suspension.
Equipment & Trim Levels
The Silverado 3500 HD Double Cab Long Bed with the Duramax engine was typically offered in higher trim levels, such as LT, LTZ, and High Country. Standard features included air conditioning, power windows and locks, a touchscreen infotainment system with Apple CarPlay and Android Auto compatibility, and a rearview camera. Higher trims added features like leather upholstery, heated and ventilated front seats, a premium sound system, and advanced safety technologies such as lane departure warning and automatic emergency braking. Optional extras included a power sunroof, a navigation system, and a bed liner. The Double Cab configuration provided comfortable seating for five passengers, with ample legroom in both rows.
Chassis & Braking
The Silverado 3500 HD features a robust chassis designed to withstand heavy loads. The front suspension utilizes an independent torsion bar and double wishbone setup, while the rear suspension employs a traditional leaf spring design. This combination provides a good balance between ride comfort and load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power even when towing. An Anti-lock Braking System (ABS) is standard. The steering system utilizes a hydraulic power steering setup, offering a responsive and predictable feel. The 4WD system allows for enhanced traction in challenging conditions, making it suitable for both on- and off-road use.
Market Reception & Comparison
The Silverado 3500 HD with the Duramax diesel engine consistently received positive reviews from automotive critics. It was praised for its powerful engine, smooth transmission, and impressive towing and hauling capabilities. Fuel economy, while not exceptional, was considered reasonable for a heavy-duty truck. Compared to its rivals, such as the Ford Super Duty and Ram 3500, the Silverado 3500 HD offered a competitive combination of performance, features, and value. Some critics noted that the interior design was not as luxurious as some competitors, but the overall functionality and durability were highly regarded.
Legacy
The Duramax L5P engine and Allison 10-speed transmission have proven to be a reliable and durable powertrain combination. These trucks continue to hold their value well in the used car market, reflecting their reputation for dependability. While diesel engines require more maintenance than gasoline engines, the Duramax L5P is known for its longevity and relatively low maintenance costs. The Silverado 3500 HD IV (T1XX) Double Cab Long Bed with the 6.6L Duramax remains a popular choice for buyers seeking a capable and reliable heavy-duty truck, capable of handling demanding tasks for years to come.
