The Chevrolet Silverado 2500HD III (K2XX) Regular Cab Long Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 445 horsepower and paired with a 6-speed Allison automatic transmission, represents a significant offering in the heavy-duty pickup truck segment. Produced from 2017 to 2019, this configuration was aimed at buyers needing substantial towing and hauling capacity, particularly in the American market where heavy-duty trucks are a popular choice for both work and recreational purposes. This variant occupied a premium position within the Silverado 2500HD lineup, offering a balance of power, capability, and refinement.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD III (K2XX) Regular Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (445 Hp) 4WD Automatic |
| Start of production | 2017 |
| End of production | 2019 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 6.2 kg/Hp, 161.8 Hp/tonne |
| Weight-to-torque ratio | 2.2 kg/Nm, 448.6 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 | 29.7 l (31.38 US qt | 26.13 UK qt) |
| Kerb Weight | 2751 kg (6064.92 lbs.) |
| Max. weight | 4309 kg (9499.72 lbs.) |
| Max load | 1558 kg (3434.8 lbs.) |
| Trunk (boot) space – maximum | 2162 l (76.35 cu. ft.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 6577 kg (14499.8 lbs.) |
| Length | 5699 mm (224.37 in.) |
| Width including mirrors | 2035 mm (80.12 in.) |
| Height | 1975 mm (77.76 in.) |
| Wheelbase | 3393 mm (133.58 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Minimum turning circle (turning diameter) | 14 m (45.93 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 R17; 265/70 R18; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
INTRODUCTION
The Chevrolet Silverado 2500HD III, specifically the Regular Cab Long Box configuration with the 6.6L Duramax diesel and Allison automatic, was introduced as part of the K2XX generation of Silverado and Sierra heavy-duty trucks. This generation, launched in 2017, represented a significant overhaul of the platform, focusing on increased strength, improved ride quality, and enhanced technology. The Regular Cab configuration, while less popular than Crew Cab models, catered to buyers prioritizing functionality and work-oriented needs. The Long Box provided ample bed space for hauling, making it a practical choice for contractors, farmers, and those requiring substantial cargo capacity. This particular powertrain combination was positioned as a premium offering, bridging the gap between the standard gasoline engines and the even more powerful, often more expensive, configurations.
Powertrain & Engine Architecture
At the heart of this Silverado 2500HD lies the Duramax L5P 6.6-liter turbocharged diesel V8 engine. This engine is a testament to modern diesel technology, featuring a cast iron block, aluminum cylinder heads, and a robust rotating assembly designed for high torque output and longevity. The L5P utilizes a diesel commonrail fuel injection system, delivering highly pressurized fuel directly into the cylinders for efficient combustion. The turbocharger, coupled with an intercooler, forces more air into the engine, boosting power and torque. The engine employs an overhead valve (OHV) valvetrain, a design choice favored for its simplicity and durability. The 6-speed Allison automatic transmission is a heavy-duty unit specifically engineered to handle the immense torque produced by the Duramax engine. It features electronically controlled shifts and a lock-up torque converter for improved fuel efficiency. The Allison transmission is renowned for its reliability and smooth operation, making it a key component of the Silverado 2500HD’s towing and hauling capabilities.
Driving Characteristics
The 445 horsepower and 910 lb-ft of torque delivered by the Duramax/Allison combination translate into impressive real-world performance. While not as quick off the line as gasoline-powered trucks, the Silverado 2500HD excels in situations requiring substantial pulling power. The Allison transmission’s gear ratios are optimized for towing, providing ample torque multiplication at lower speeds. Compared to the 6.0L gasoline V8, the Duramax offers significantly more torque, making it far superior for heavy loads. Compared to higher-output Duramax variants (available in later years), this 445 hp version provides a good balance of power and fuel economy. The automatic transmission simplifies operation, especially for drivers unfamiliar with manual transmissions or those frequently operating in stop-and-go traffic. However, some drivers may prefer the more direct control offered by a manual transmission.
Equipment & Trim Levels
The Regular Cab Long Box 6.6L Duramax typically came standard with features like air conditioning, power windows and locks, a basic infotainment system, and a tilt steering wheel. Higher trim levels, such as the LT and High Country, added features like leather upholstery, heated and ventilated seats, a premium sound system, and advanced safety technologies. Optional extras included a navigation system, a rear vision camera, and various towing packages. The interior, while functional, was generally more utilitarian than the Crew Cab models, reflecting the truck’s work-oriented focus. The dashboard layout was straightforward and easy to use, prioritizing practicality over luxury.
Chassis & Braking
The Silverado 2500HD 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, 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 heavy loads. An Anti-lock Braking System (ABS) is standard. The rear axle ratios varied depending on the specific configuration, influencing both towing capacity and fuel economy.
Market Reception & Comparison
The Silverado 2500HD with the 6.6L Duramax and Allison automatic received generally positive reviews from automotive critics. The engine was praised for its power, torque, and refinement, while the Allison transmission was lauded for its smooth operation and durability. Fuel economy, while not exceptional, was considered reasonable for a heavy-duty truck of this size and capability. Compared to the gasoline-powered Silverado 2500HD models, the Duramax diesel offered significantly better towing capacity and fuel efficiency, albeit at a higher initial cost. Compared to competing trucks from Ford and Ram, the Silverado 2500HD was often seen as a strong contender, offering a compelling combination of performance, reliability, and value.
Legacy
The Duramax L5P engine and Allison transmission pairing has proven to be exceptionally reliable, with many examples exceeding 200,000 miles with proper maintenance. These trucks continue to hold their value well in the used car market, particularly those that have been well-maintained and haven’t been subjected to excessive abuse. The 2017-2019 Silverado 2500HD represents a sweet spot in the K2XX generation, offering a blend of modern technology, proven durability, and a relatively affordable price point. The combination of a robust powertrain, a capable chassis, and a practical interior makes it a popular choice for buyers seeking a heavy-duty truck that can handle a wide range of tasks.
