Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD IV (T1XX) Double Cab Long Bed |
| Type (Engine) | 6.6 Duramax V8 (445 Hp) 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 | 7.6 kg/Hp, 131.9 Hp/tonne |
| Weight-to-torque ratio | 2.7 kg/Nm, 365.7 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 | 3374 kg (7438.4 lbs.) |
| Max. weight | 4944 kg (10899.65 lbs.) |
| Max load | 1570 kg (3461.26 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%) | 8182 kg (18038.22 lbs.) |
| Length | 6514 mm (256.46 in.) |
| Width including mirrors | 2079 mm (81.85 in.) |
| Height | 2027 mm (79.8 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) | 258 mm (10.16 in.) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine. |
| Number of gears and type of gearbox | 10 gears, automatic transmission Allison |
The Chevrolet Silverado 2500 HD IV (T1XX) Double Cab Long Bed, equipped with the 6.6-liter Duramax V8 engine and a ten-speed automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineup. Produced from 2020 to 2023, this variant occupied a premium position within the fourth generation (T1XX) Silverado HD series, targeting buyers requiring substantial towing capacity and diesel-powered performance. It was designed to compete directly with offerings from Ford and Ram in the increasingly popular heavy-duty truck segment of the American market.
Powertrain & Engine Architecture
The heart of this Silverado 2500 HD variant is the 6.6-liter Duramax L5P turbocharged diesel V8 engine. This engine, a staple of Chevrolet’s heavy-duty lineup 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 turbocharger, coupled with an intercooler, provides increased air density for enhanced power output. The engine employs an overhead valve (OHV) valvetrain, a design choice prioritizing durability and low-end torque. The ten-speed Allison automatic transmission, introduced with the T1XX generation, replaced the previous six-speed unit. This new transmission offered closer gear ratios, improving both acceleration and fuel efficiency, and providing smoother shifting. The transmission is electronically controlled, adapting to driving conditions and driver input.
Driving Characteristics
The combination of the 445 horsepower and 910 lb-ft of torque delivered by the Duramax engine and the ten-speed Allison transmission results in a truck capable of impressive performance, even when heavily loaded. While not designed for outright speed, the Silverado 2500 HD provides strong acceleration and effortless towing capabilities. The ten-speed transmission keeps the engine within its optimal power band, minimizing turbo lag and maximizing efficiency. Compared to the 6.0-liter gasoline V8 option, the Duramax offers significantly more torque, making it the preferred choice for those regularly towing large trailers or hauling heavy payloads. Compared to earlier Duramax engines, the L5P benefits from the improved gear ratios of the ten-speed Allison, resulting in a more refined and responsive driving experience.
Equipment & Trim Levels
The 6.6 Duramax V8 engine was typically offered on higher trim levels of the Silverado 2500 HD, such as the 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.
Chassis & Braking
The Silverado 2500 HD IV utilizes a fully boxed frame for enhanced rigidity and durability. The front suspension consists of an independent torsion bar setup with double wishbone control arms, while the rear suspension employs a traditional leaf spring configuration. This setup is designed to handle heavy loads and provide a comfortable ride. Braking duties are handled by ventilated disc brakes on all four wheels, with larger rotors and calipers on the front axle. An Anti-lock Braking System (ABS) is standard. The truck’s robust chassis and braking system are crucial for safely managing the vehicle’s substantial weight and towing capacity.
Market Reception & Comparison
The Silverado 2500 HD with the Duramax engine received generally positive reviews from automotive critics. The engine was praised for its power, torque, and refinement, while the ten-speed Allison transmission was lauded for its smooth shifting and improved fuel economy. Compared to the gasoline-powered Silverado 2500 HD, the Duramax variant offered superior towing capacity and fuel efficiency, albeit at a higher initial cost. Against competitors like the Ford Super Duty and Ram 2500, the Silverado 2500 HD was considered a strong contender, offering a compelling combination of performance, capability, and features.
Legacy
The Duramax L5P engine paired with the ten-speed Allison transmission has proven to be a reliable and durable powertrain. While diesel engines inherently require more maintenance than gasoline engines, the L5P has generally demonstrated good long-term reliability. In the used car market, Silverado 2500 HD models equipped with this powertrain command a premium price due to their proven performance and towing capabilities. The T1XX generation Silverado 2500 HD, and specifically this Duramax/Allison combination, represents a high point in Chevrolet’s heavy-duty truck offerings, continuing to be a popular choice for buyers seeking a capable and dependable work truck.
