The Chevrolet Silverado 3500 HD IV (T1XX) Crew Cab Long Bed, specifically equipped with the 6.6-liter Duramax V8 engine producing 445 horsepower and paired with an Allison 10-speed automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2020 to 2023, this configuration occupied a premium position within the fourth generation (T1XX) Silverado HD lineup, targeting buyers requiring substantial towing and hauling capabilities without sacrificing comfort or modern technology. The “DRW” designation indicates a Dual Rear Wheel configuration, further enhancing its capacity for demanding tasks.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD IV (T1XX) Crew Cab Long Bed |
| Type (Engine) | 6.6 Duramax V8 (445 Hp) DRW 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 | 8.2 kg/Hp, 121.6 Hp/tonne |
| Weight-to-torque ratio | 3 kg/Nm, 337.1 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 | 3661 kg (8071.12 lbs.) |
| Max. weight | 6350 kg (13999.35 lbs.) |
| Max load | 2689 kg (5928.23 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%) | 14243 kg (31400.44 lbs.) |
| Length | 6759 mm (266.1 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. |
| 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 |
| 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 2020-2023 Chevrolet Silverado 3500 HD Crew Cab Long Bed with the 6.6L Duramax engine and Allison transmission represents the pinnacle of capability within the Silverado HD range. Built on the T1XX platform, this generation focused on increased strength, improved technology, and enhanced interior refinement. The DRW (Dual Rear Wheel) configuration, combined with the potent Duramax diesel, positioned this truck squarely against competitors like the Ford F-350 and Ram 3500, appealing to commercial users, ranchers, and those needing to tow exceptionally heavy loads. This variant was a premium offering, typically found in LTZ, High Country, and Work Truck trims.
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, utilizing a common-rail direct fuel injection system for precise fuel delivery. The L5P boasts a cast iron block and aluminum cylinder heads, contributing to its durability. The turbocharger, coupled with an intercooler, provides increased air density for enhanced combustion and power output. The engine produces 445 horsepower at 2800 rpm and a massive 910 lb-ft (1234 Nm) of torque at 1600 rpm. This torque figure is crucial for heavy towing and hauling. The Allison 10-speed automatic transmission is specifically calibrated to handle the engine’s output, providing smooth and efficient power delivery. The transmission features electronically controlled shifts and a tow/haul mode for optimized performance when towing.
Driving Characteristics
The Silverado 3500 HD DRW with the Duramax and Allison transmission delivers a driving experience focused on capability and stability. While not a performance-oriented truck, the engine provides ample power for accelerating with and without a load. The 10-speed Allison transmission allows for tight gear spacing, keeping the engine in its optimal power band. The DRW configuration significantly enhances stability when towing, reducing sway and providing a more confident feel. Compared to the 6.0L gasoline engine option or even the lighter-duty 2500 HD models, this variant offers a substantial increase in towing capacity and overall robustness. The ride quality, while firm due to the heavy-duty suspension, is surprisingly comfortable for a truck of this size, especially in Crew Cab configuration.
Equipment & Trim Levels
The 6.6L Duramax/Allison combination was typically offered on higher trim levels like the LTZ and High Country. Standard features included a large infotainment touchscreen with Apple CarPlay and Android Auto compatibility, a premium sound system, leather upholstery, heated and ventilated front seats, and a comprehensive suite of safety features. Optional extras included a power sunroof, a rear-seat entertainment system, and advanced trailering technologies like integrated trailer brake control and a bed view camera. The Work Truck trim offered a more basic interior but still included essential features for commercial use.
Chassis & Braking
The Silverado 3500 HD features a fully boxed frame constructed from high-strength steel, providing a solid foundation for heavy loads. The front suspension utilizes an independent torsion bar and double wishbone design, while the rear suspension employs a traditional leaf spring setup. The DRW configuration utilizes a wider rear axle and dual rear wheels for increased stability and load capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) is standard, enhancing safety during emergency braking situations.
Market Reception & Comparison
The Silverado 3500 HD DRW with the Duramax engine received generally positive reviews from automotive critics. It was praised for its immense towing capacity, powerful engine, and comfortable ride. Fuel economy, while typical for a heavy-duty diesel truck, was a point of consideration. Compared to the gasoline-powered Silverado 3500 HD, the Duramax offered significantly better torque and towing capability, albeit at a higher initial cost. Reliability has been generally good, with the Duramax engine proving to be a durable and long-lasting powerplant. However, diesel emissions systems can require maintenance and potential repairs over the long term.
Legacy
The 2020-2023 Chevrolet Silverado 3500 HD DRW with the 6.6L Duramax engine and Allison transmission continues to hold its value in the used car market. The Duramax engine is highly regarded for its longevity and performance, making these trucks desirable for buyers seeking a capable and reliable workhorse. While newer models offer updated technology and features, this generation represents a sweet spot for those seeking a proven and capable heavy-duty truck at a reasonable price. The L5P Duramax engine is known for its ability to withstand high mileage with proper maintenance, ensuring that these trucks will remain on the road for years to come.
