The Chevrolet Silverado 2500HD III (K2XX) Double Cab Standard Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 445 horsepower and paired with an Allison automatic transmission, was a key offering in Chevrolet’s heavy-duty truck lineup from 2017 to 2019. This configuration represented a balance between capability and usability, targeting customers needing substantial towing and hauling capacity without the extreme bulk of the crew cab models. It occupied a significant position within the K2XX generation, known for its enhanced strength, refinement, and technology compared to its predecessors.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD III (K2XX) Double Cab Standard Box |
| Type (Engine) | 6.6 Duramax TD V8 (445 Hp) Automatic |
| Start of production | 2017 |
| End of production | 2019 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.2 kg/Hp, 139.7 Hp/tonne |
| Weight-to-torque ratio | 2.6 kg/Nm, 387.3 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 | 3186 kg (7023.93 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1350 kg (2976.24 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 | 5841 mm (229.96 in.) |
| Width including mirrors | 2045 mm (80.51 in.) |
| Height | 1984 mm (78.11 in.) |
| Wheelbase | 3662 mm (144.17 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Ride height (ground clearance) | 218 mm (8.58 in.) |
| Minimum turning circle (turning diameter) | 15 m (49.21 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| 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 |
| Tires size | 245/75 R17; 265/70 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 2500HD variant is the Duramax L5P 6.6-liter turbocharged diesel V8. This engine is 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. The turbocharger, coupled with an intercooler, provides increased air density for improved power and efficiency. The engine’s OHV (Overhead Valve) valvetrain contributes to its durability and low-end torque characteristics. The Allison 1000 six-speed automatic transmission is specifically engineered to handle the immense torque produced by the Duramax engine. It features a lock-up torque converter for improved fuel economy and a heavy-duty cooling system to prevent overheating under demanding conditions. The transmission’s gear ratios are optimized for both towing and everyday driving, providing a balance of power and efficiency.
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 shifts smoothly and predictably, providing ample power for highway cruising and steep grade climbs, even when heavily loaded. Compared to the 6.0L gasoline V8 option, the Duramax offers significantly more torque at lower RPMs, making it ideal for towing. Compared to higher-output Duramax variants, this 445 hp version provides a more manageable power delivery, making it easier to control for drivers less experienced with heavy-duty trucks. The gear ratios in the Allison transmission are tuned to maximize fuel efficiency while still providing sufficient power for most tasks.
Equipment & Trim Levels
The Double Cab Standard Box configuration typically came standard with features like air conditioning, power windows and locks, a basic infotainment system with a touchscreen display, and a rearview camera. Interior upholstery was generally cloth, with options for leather available as upgrades. The dashboard layout was functional and straightforward, prioritizing ease of use over luxury. Common optional extras included a navigation system, upgraded audio system, heated and ventilated front seats, and various driver-assistance features like lane departure warning and forward collision alert. Trim levels, such as LT and LTZ, offered progressively more features and refinements.
Chassis & Braking
The K2XX chassis is a fully boxed frame constructed from high-strength steel, providing a solid foundation for the truck’s heavy-duty capabilities. The front suspension utilizes an independent torsion bar setup with double wishbones, offering a comfortable ride and improved 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 the specific configuration, influencing both towing capacity and fuel economy.
Market Reception & Comparison
The 2017-2019 Silverado 2500HD with the 6.6L Duramax and Allison transmission received generally positive reviews. Critics praised its robust towing capacity, comfortable ride, and refined interior. Fuel economy, while not exceptional, was considered competitive for a heavy-duty diesel truck. Compared to the gasoline-powered Silverado 2500HD, the Duramax variant commanded a higher price but offered significantly lower operating costs for high-mileage users and those who frequently tow. Compared to Ford’s Super Duty and Ram’s heavy-duty trucks, 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 exceptionally reliable, with many examples exceeding 200,000 miles with proper maintenance. The K2XX generation Silverado 2500HD is well-regarded in the used truck market, commanding relatively high resale values. The 6.6-liter Duramax remains a popular choice for buyers seeking a powerful and dependable diesel engine. Regular maintenance, including oil changes, fuel filter replacements, and coolant flushes, is crucial for ensuring the longevity of this powertrain. The combination of durability, capability, and relative refinement has cemented the Silverado 2500HD’s reputation as a workhorse truck capable of handling demanding tasks for years to come.
