The Chevrolet Silverado 2500 HD IV (T1XX) Crew Cab Long Bed, equipped with the 6.6-liter Duramax V8 engine producing 445 horsepower and paired with a 10-speed automatic transmission and four-wheel drive, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2020 through 2023, this configuration occupied a premium position within the fourth generation (T1XX) Silverado 2500/3500 HD lineup, targeting buyers requiring substantial towing and hauling capabilities without sacrificing everyday usability. It was designed to compete directly with offerings from Ford (Super Duty series) and Ram (2500/3500 HD series) in the North American heavy-duty truck market.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD IV (T1XX) Crew Cab Long Bed |
| Type (Engine) | 6.6 Duramax V8 (445 Hp) 4WD 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, 124.4 Hp/tonne |
| Weight-to-torque ratio | 2.9 kg/Nm, 345 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 | 3577 kg (7885.94 lbs.) |
| Max. weight | 5158 kg (11371.44 lbs.) |
| Max load | 1581 kg (3485.51 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%) | 8392 kg (18501.19 lbs.) |
| Length | 6759 mm (266.1 in.) |
| Width including mirrors | 2079 mm (81.85 in.) |
| Height | 2023 mm (79.65 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) | 256 mm (10.08 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; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
Powertrain & Engine Architecture
The heart of this Silverado 2500 HD variant is the Duramax L5P 6.6-liter turbocharged diesel V8 engine. This engine, a mainstay of GM’s heavy-duty truck offerings for years, utilizes a cast iron block and aluminum cylinder heads. The L5P features a common-rail direct fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The engine employs an overhead valve (OHV) valvetrain, a design choice prioritizing durability and low-end torque. A single variable geometry turbocharger with an intercooler provides forced induction, boosting power and efficiency. The 10-speed Allison automatic transmission, a crucial component, is designed to handle the engine’s substantial torque output and provide smooth, efficient shifting. This transmission replaced the previous 6-speed Allison in the 2020 model year, contributing to improved fuel economy and towing performance.
Driving Characteristics
The 445 horsepower and 910 lb-ft of torque delivered by the Duramax engine and 10-speed Allison transmission translate to impressive real-world performance. While not as quick accelerating as gasoline-powered trucks, the Silverado 2500 HD excels in towing and hauling. The 10-speed transmission’s closely spaced gear ratios keep the engine within its optimal power band, even when carrying heavy loads or climbing steep grades. Compared to the 6.6L gasoline V8 option, the Duramax offers significantly more torque at lower RPMs, making it ideal for demanding tasks. Compared to the earlier 6-speed Allison, the 10-speed provides a wider gear ratio spread, improving both fuel economy and towing stability. The four-wheel-drive system provides enhanced traction in various conditions, making it suitable for both on-road and off-road use.
Equipment & Trim Levels
The 6.6L Duramax/10-speed automatic combination was typically offered on higher trim levels of the Silverado 2500 HD, such as the LTZ, High Country, and Work Truck. Standard features included a spacious Crew Cab interior with seating for five, air conditioning, power windows and locks, and a basic infotainment system. Higher trims added features like leather upholstery, heated and ventilated front seats, a premium sound system, and advanced safety technologies. Optional extras included a power sunroof, navigation system, and various towing packages. The Long Bed configuration provided ample cargo space for hauling materials or equipment.
Chassis & Braking
The Silverado 2500 HD IV utilizes a fully boxed frame for enhanced rigidity and durability. The front suspension features an independent torsion bar setup with double wishbone control arms, while the rear suspension employs a traditional leaf spring design. This configuration is optimized for handling heavy loads and providing a comfortable ride. Braking duties are handled by ventilated disc brakes on all four wheels, with larger rotors at the front. An Anti-lock Braking System (ABS) is standard. The heavy-duty chassis and braking system are designed to safely manage the truck’s substantial weight and towing capacity.
Market Reception & Comparison
The Silverado 2500 HD with the Duramax engine and 10-speed transmission received generally positive reviews from automotive critics. The engine was praised for its abundant torque and smooth power delivery, while the transmission was lauded for its responsiveness and efficiency. Fuel economy, while not exceptional, was considered competitive for a heavy-duty truck. Compared to the gasoline-powered Silverado 2500 HD, the Duramax variant offered superior towing capacity and fuel efficiency, albeit at a higher initial cost. Reliability reports have been generally favorable, although diesel engines can be more expensive to maintain than gasoline engines due to the complexity of the emissions control systems.
Legacy
The 2020-2023 Chevrolet Silverado 2500 HD with the 6.6L Duramax and 10-speed Allison represents a well-engineered and capable heavy-duty truck. The Duramax L5P engine has proven to be a durable and reliable powerplant, and the 10-speed Allison transmission significantly improved the truck’s overall performance and efficiency. On the used market, these trucks hold their value well, particularly those in good condition with well-documented maintenance histories. They remain a popular choice for buyers seeking a powerful and dependable truck for work or recreational purposes.
