The Chevrolet Silverado 3500 HD IV (T1XX) Crew Cab Long Bed, 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 through 2023, this variant occupied a premium position within the Silverado 3500 HD lineup, targeting buyers requiring substantial towing and hauling capabilities without sacrificing comfort or modern technology. It’s part of the fourth generation (T1XX) of the Silverado HD series, known for its increased strength, refined interior, and advanced features.
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) 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 kg/Hp, 125 Hp/tonne |
| Weight-to-torque ratio | 2.9 kg/Nm, 346.6 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 | 3560 kg (7848.46 lbs.) |
| Max. weight | 5398 kg (11900.55 lbs.) |
| Max load | 1838 kg (4052.1 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%) | 9675 kg (21329.72 lbs.) |
| Length | 6759 mm (266.1 in.) |
| Width including mirrors | 2079 mm (81.85 in.) |
| Height | 2049 mm (80.67 in.) |
| Wheelbase | 4369 mm (172.01 in.) |
| Front track | 1731 mm (68.15 in.) |
| Rear (Back) track | 1736 mm (68.35 in.) |
| Ride height (ground clearance) | 283 mm (11.14 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, 360×34 mm |
| Tires size | 265/70 R17; 245/75 R17; 275/70 R18 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
Powertrain & Engine Architecture
The heart of this Silverado 3500 HD variant is the Duramax L5P 6.6-liter V8 diesel engine. This engine, a staple in GM’s heavy-duty lineup, utilizes a cast iron block and aluminum cylinder heads. It employs a Bosch common-rail fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The L5P features a variable geometry turbocharger (VGT) and an intercooler to maximize power and efficiency. The overhead valve (OHV) valvetrain, while a traditional design, is known for its durability and reliability. The Allison 10-speed automatic transmission is a crucial component, designed to handle the engine’s substantial torque output. This transmission offers smooth shifting and a wide gear ratio spread, optimizing both towing performance and fuel economy.
Driving Characteristics
The combination of the 445 hp Duramax engine and the 10-speed Allison transmission delivers a robust driving experience. While not as quick as lighter-duty trucks, the Silverado 3500 HD excels in situations demanding significant pulling power. The 10-speed transmission keeps the engine within its optimal power band, even when hauling heavy loads. The gear ratios are well-suited for both highway cruising and low-speed towing. Compared to the 6.6L gasoline engine option, the Duramax provides significantly more torque at lower RPMs, making it ideal for demanding tasks. Compared to the earlier 6-speed Allison, the 10-speed offers closer ratios and improved fuel efficiency. The ride quality, even unladen, is surprisingly comfortable for a heavy-duty truck, thanks to the refined suspension tuning.
Equipment & Trim Levels
The Silverado 3500 HD IV Crew Cab Long Bed with the Duramax engine typically came in higher trim levels such as LTZ or 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 like automatic emergency braking and lane departure warning. Optional extras included a power sunroof, a rear-seat entertainment system, and advanced trailering technologies like a bed view camera and trailer tire pressure monitoring. The Crew Cab configuration provides ample space for passengers, while the Long Bed offers a generous cargo capacity.
Chassis & Braking
The Silverado 3500 HD features a fully boxed frame constructed from high-strength steel, providing a solid foundation for heavy-duty use. The front suspension utilizes an independent torsion bar setup with double wishbones, while the rear suspension employs a traditional leaf spring design. This configuration balances ride comfort with load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power even when heavily loaded. The front brakes measure 355x40mm, while the rear brakes are 360x34mm. An Anti-lock Braking System (ABS) is standard, enhancing safety and control.
Market Reception & Comparison
The Silverado 3500 HD with the Duramax engine and Allison transmission consistently received positive reviews from automotive critics. It was praised for its powerful engine, smooth transmission, comfortable ride, and advanced technology. Fuel economy, while not exceptional, was considered competitive for a heavy-duty truck. Compared to the Ford Super Duty and Ram HD trucks, the Silverado 3500 HD offered a compelling combination of capability, comfort, and value. The Duramax engine was often cited as a key advantage, offering superior torque and reliability compared to some competitors’ gasoline engines.
Legacy
The Duramax L5P engine paired with the Allison 10-speed transmission has proven to be a durable and reliable powertrain. These trucks have maintained strong resale values in the used car market, reflecting their reputation for dependability. While diesel engines require more diligent maintenance than gasoline engines, the Duramax L5P has generally been considered a long-lasting and robust engine. Common maintenance items include regular oil changes, fuel filter replacements, and diesel exhaust fluid (DEF) refills. The Silverado 3500 HD IV with this powertrain remains a popular choice for buyers seeking a capable and reliable heavy-duty truck.
