The Chevrolet Silverado 2500HD III (K2XX) Crew Cab Standard Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 445 horsepower and paired with a 6-speed Allison automatic transmission and four-wheel drive, was a key offering in Chevrolet’s heavy-duty truck lineup from 2017 to 2019. This configuration represented a significant balance between capability, comfort, and technology within the broader Silverado 2500HD range, targeting buyers needing serious towing and hauling capacity without sacrificing everyday usability. It was part of the third generation of the K2XX platform, which brought substantial improvements in strength, refinement, and interior space compared to its predecessors.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD III (K2XX) Crew Cab Standard Box |
| Type (Engine) | 6.6 TD V8 (445 Hp) 4WD Automatic |
| Start of production | 2017 year |
| End of production | 2019 year |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.6 kg/Hp, 131.5 Hp/tonne |
| Weight-to-torque ratio | 2.7 kg/Nm, 364.5 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 | 29.7 l (31.38 US qt | 26.13 UK qt) |
| Kerb Weight | 3385 kg (7462.65 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1151 kg (2537.52 lbs.) |
| Trunk (boot) space – maximum | 1728 l (61.02 cu. ft.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 5897 kg (13000.66 lbs.) |
| Length | 6083 mm (239.49 in.) |
| Width including mirrors | 2045 mm (80.51 in.) |
| Height | 1987 mm (78.23 in.) |
| Wheelbase | 3904 mm (153.7 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Minimum turning circle (turning diameter) | 15.7 m (51.51 ft.) |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| Number of gears and type of gearbox | 6 gears, automatic transmission Allison |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 350×40 mm |
| Rear brakes | Ventilated discs, 360×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 235/80 R17; 265/70 R18; 275/65 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 2500HD variant is the 6.6-liter Duramax L5P turbo-diesel V8 engine. This engine represents a significant evolution of the Duramax design, featuring a cast iron block, aluminum cylinder heads, and a robust rotating assembly designed for high torque output. The L5P utilizes a diesel commonrail fuel injection system, delivering fuel at extremely high pressures for optimized combustion. A single variable geometry turbocharger (VGT) with an intercooler provides increased air intake, boosting power and efficiency. The engine employs an overhead valve (OHV) valvetrain, a design choice favored for its durability and low-end torque characteristics. The Allison 1000 six-speed automatic transmission is specifically calibrated to handle the immense torque produced by the Duramax engine. This transmission is known for its durability and smooth shifting, crucial for heavy-duty applications.
Driving Characteristics
The 445 horsepower and 910 lb-ft of torque delivered by this combination translate into impressive real-world performance. While not as quick off the line as gasoline-powered trucks, the Duramax offers a broad, flat torque curve, making it exceptionally capable for towing and hauling heavy loads. The Allison transmission’s gear ratios are optimized for both work and highway cruising. Compared to the 6.0L gasoline V8 option, the diesel provides significantly more low-end grunt, making it easier to accelerate with a loaded trailer. Compared to higher-output Duramax variants (available in later years), this 445 hp version offers a balance between power and fuel economy. The automatic transmission, while smooth, doesn’t offer the direct control of a manual transmission, but it simplifies operation for drivers who prioritize ease of use.
Equipment & Trim Levels
The Silverado 2500HD Crew Cab Standard Box with the 6.6L Duramax and Allison automatic typically fell into the mid-range of trim levels, often corresponding to the LT or LTZ trims. Standard features included air conditioning, power windows and locks, a basic infotainment system with a touchscreen display, and cloth upholstery. The Crew Cab configuration provided ample passenger space, making it suitable for both work and family use. Optional extras included leather upholstery, heated and ventilated front seats, a premium audio system, navigation, and advanced safety features like lane departure warning and forward collision alert. The Standard Box length offered a good compromise between cargo capacity and maneuverability.
Chassis & Braking
The K2XX platform 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 wishbone control arms, offering a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power even when towing. ABS (Anti-lock Braking System) is standard. The rear axle ratios varied depending on specific configurations, influencing both towing capacity and fuel economy.
Market Reception & Comparison
The Silverado 2500HD with the 6.6L Duramax and Allison automatic was generally well-received by critics and consumers alike. It was praised for its powerful engine, smooth transmission, and comfortable ride. Fuel economy, while not exceptional, was considered reasonable for a heavy-duty truck. Compared to the gasoline-powered Silverado 2500HD, the diesel offered superior towing capacity and fuel efficiency when hauling heavy loads. Compared to competing trucks from Ford and Ram, the Silverado 2500HD was often seen as a strong contender, offering a compelling combination of capability, comfort, and value.
Legacy
The Duramax L5P engine and Allison transmission pairing have proven to be remarkably durable and reliable. Well-maintained examples of this powertrain continue to command strong resale values in the used truck market. While some early L5P engines experienced issues with injector failure, these were largely addressed through updated calibrations and improved injector designs. The K2XX platform Silverado 2500HD remains a popular choice for buyers seeking a capable and reliable heavy-duty truck, and the 6.6L Duramax/Allison combination is widely regarded as one of the best diesel powertrains ever offered in a consumer truck.
