The Chevrolet Silverado 2500HD III (K2XX) Double Cab Standard Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine and a six-speed Allison automatic transmission, was a prominent offering in Chevrolet’s heavy-duty pickup truck lineup from 2015 to 2017. This configuration represented a sweet spot for buyers needing substantial towing and hauling capability without sacrificing everyday drivability. Positioned as a mid-to-upper trim level within the 2500HD range, it catered to customers like contractors, ranchers, and those requiring a powerful truck for work and recreational purposes. The K2XX platform, introduced in 2014, brought significant improvements in ride quality, interior refinement, and overall capability compared to its predecessor.
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 (397 Hp) Automatic |
| Start of production | 2015 |
| End of production | 2017 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.9 kg/Hp, 125.9 Hp/tonne |
| Weight-to-torque ratio | 3 kg/Nm, 328.9 Nm/tonne |
| Power | 397 Hp @ 3000 rpm |
| Power per litre | 60.2 Hp/l |
| Torque | 1037 Nm @ 1600 rpm (764.85 lb.-ft. @ 1600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax LML |
| Engine displacement | 6599 cm3 (402.7 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 | 22.4 l (23.67 US qt | 19.71 UK qt) |
| Kerb Weight | 3153 kg (6951.18 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1383 kg (3048.99 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, 355×40 mm |
| Rear brakes | Ventilated discs, 360×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 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 LML 6.6-liter turbocharged diesel V8. This engine is a testament to diesel engineering, featuring a cast iron block, aluminum cylinder heads, and a robust rotating assembly designed for high torque output and longevity. The LML generation of the Duramax introduced a revised turbocharger, improved fuel injection system, and enhanced glow plug technology for improved cold-start performance and reduced emissions. The common-rail fuel injection system delivers fuel at extremely high pressures, optimizing combustion efficiency and power. The overhead valve (OHV) valvetrain, while seemingly traditional, is known for its durability and simplicity. The six-speed Allison automatic transmission, a heavy-duty unit specifically designed for trucks of this caliber, is renowned for its smooth shifting and ability to handle the engine’s substantial torque. It features a lock-up torque converter for improved fuel economy at highway speeds.
Driving Characteristics
The 6.6L Duramax with the Allison automatic delivers a driving experience focused on capability and control. While not a sports truck, the 397 horsepower and, more importantly, the 765 lb-ft of torque provide effortless acceleration, even when heavily loaded. The Allison transmission is well-tuned, offering smooth and precise shifts. Compared to the gasoline-powered Silverado 2500HD models, the diesel offers significantly more low-end torque, making it ideal for towing and hauling. The automatic transmission, while convenient, does result in a slight performance deficit compared to the available manual transmission, which allows for more direct control over gear selection. However, the automatic’s ease of use is a major selling point for many drivers. The gear ratios are optimized for towing, with a relatively low first gear for getting heavy loads moving and a tall overdrive gear for efficient highway cruising.
Equipment & Trim Levels
The Double Cab Standard Box configuration typically came standard with features like air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the LT and LTZ, added features like leather upholstery, heated seats, a premium audio system, navigation, and advanced safety features. Optional extras included a sunroof, upgraded wheels, and various towing packages. The Standard Box length provided a good balance between cargo space and maneuverability. Interior materials were generally durable and functional, reflecting the truck’s work-oriented nature.
Chassis & Braking
The Silverado 2500HD utilizes a fully boxed frame for exceptional strength and rigidity. The front suspension features an independent torsion bar setup with double wishbone control arms, providing 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 at all four corners, providing ample stopping power. An Anti-lock Braking System (ABS) is standard. The rear brakes are slightly smaller in diameter than the front brakes, reflecting the weight distribution of the truck.
Market Reception & Comparison
The 6.6L Duramax/Allison combination was widely praised by automotive critics for its power, refinement, and reliability. It consistently outperformed the gasoline engine options in towing and hauling tests. Fuel economy, while not exceptional, was competitive for a heavy-duty diesel truck. Compared to other diesel-powered trucks in the same class, such as the Ford Super Duty and Ram 2500, the Silverado 2500HD offered a compelling combination of capability, comfort, and value. Some critics noted that the interior design was less luxurious than some competitors, but the Silverado’s overall robustness and dependability were highly regarded.
Legacy
The Duramax LML engine has proven to be exceptionally durable, with many examples exceeding 200,000 miles with proper maintenance. The Allison transmission is equally reliable. On the used car market, these Silverado 2500HD models hold their value well, particularly those in good condition with well-documented maintenance histories. They remain a popular choice for buyers seeking a capable and dependable heavy-duty truck. Common maintenance items include regular oil changes, fuel filter replacements, and coolant flushes. The LML Duramax is known for its relatively low maintenance requirements compared to some earlier diesel engines. The K2XX platform Silverado 2500HD represents a significant step forward in heavy-duty truck design, offering a blend of capability, comfort, and reliability that continues to appeal to buyers today.
