The Chevrolet Silverado 2500HD III (K2XX) Crew Cab Long Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine and a six-speed Allison automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2015 to 2017, this configuration occupied a premium position within the Silverado 2500HD lineup, targeting buyers requiring substantial towing and hauling capacity without sacrificing everyday usability. It was part of the third generation of the K2XX platform, 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) Crew Cab Long 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 | 8.2 kg/Hp, 121.7 Hp/tonne |
| Weight-to-torque ratio | 3.1 kg/Nm, 317.9 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 | 3262 kg (7191.48 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1274 kg (2808.69 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 | 6563 mm (258.39 in.) |
| Width including mirrors | 2045 mm (80.51 in.) |
| Height | 1981 mm (77.99 in.) |
| Wheelbase | 4258 mm (167.64 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Ride height (ground clearance) | 211 mm (8.31 in.) |
| Minimum turning circle (turning diameter) | 17.1 m (56.1 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 |
| 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 |
INTRODUCTION
The 2015-2017 Chevrolet Silverado 2500HD Crew Cab Long Box with the 6.6L Duramax diesel and Allison automatic was a cornerstone of Chevrolet’s heavy-duty truck offerings. Positioned as a premium trim, it catered to customers needing a robust work truck capable of significant towing and payload, while also providing a comfortable and well-equipped cabin. This model year represented a mid-cycle refresh of the K2XX platform, introducing updated styling, enhanced interior materials, and improved technology features. The Crew Cab configuration offered ample passenger space, making it suitable for both work and family use, while the Long Box provided a generous cargo bed for hauling materials.
Powertrain & Engine Architecture
At the heart of this Silverado 2500HD lies the Duramax LML 6.6-liter turbocharged diesel V8 engine. This engine is renowned for its durability and torque output. The LML featured a revised turbocharger, improved fuel injection system, and enhanced glow plug technology compared to earlier Duramax engines. The engine utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The overhead valve (OHV) valvetrain, while seemingly dated, proved reliable and contributed to the engine’s low-end torque characteristics. The Allison 1000 six-speed automatic transmission is specifically designed to handle the immense torque produced by the Duramax engine. This transmission features a lock-up torque converter for improved fuel efficiency and a heavy-duty cooling system to prevent overheating under demanding conditions. The transmission’s gear ratios are optimized for both towing and highway cruising, providing a balance of power and efficiency.
Driving Characteristics
The Silverado 2500HD 6.6L Duramax Automatic delivers a driving experience focused on capability and stability. While not a performance-oriented truck, the engine’s 397 horsepower and, more importantly, its 765 lb-ft of torque provide ample power for towing heavy loads and accelerating with authority. The Allison transmission shifts smoothly and decisively, contributing to a refined driving experience. Compared to gasoline-powered Silverado 2500HD models, the Duramax diesel offers significantly more low-end torque, making it easier to pull heavy trailers up steep grades. Compared to manual transmission equipped Duramax models, the automatic provides ease of use, particularly in stop-and-go traffic. However, some drivers may prefer the greater control offered by a manual gearbox. The long wheelbase and heavy-duty suspension contribute to a comfortable ride, even when unladen, although the truck’s size can make it challenging to maneuver in tight spaces.
Equipment & Trim Levels
The Silverado 2500HD Crew Cab Long Box 6.6L Duramax Automatic was typically offered in LTZ and High Country trim levels. Standard features included air conditioning, power windows and locks, a rearview camera, and a basic infotainment system. LTZ trims added leather upholstery, heated front seats, a premium audio system, and additional chrome exterior trim. The High Country trim represented the pinnacle of luxury, featuring unique exterior styling, upgraded interior materials, and advanced technology features such as a navigation system and a forward collision alert system. Optional extras included a sunroof, a rear-seat entertainment system, and a spray-in bedliner.
Chassis & Braking
The K2XX platform chassis is a fully boxed frame constructed from high-strength steel, providing a robust foundation for the heavy-duty truck. The front suspension utilizes an independent torsion bar setup with double wishbone control arms, offering a comfortable ride and precise 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 truck’s steering system utilizes a recirculating ball mechanism, providing a stable and predictable steering feel.
Market Reception & Comparison
The Silverado 2500HD 6.6L Duramax Automatic received generally positive reviews from automotive critics. It was praised for its powerful engine, smooth transmission, comfortable ride, and impressive towing capacity. Fuel economy, while not a primary concern for heavy-duty truck buyers, was considered acceptable for a vehicle of its size and capability. Compared to the gasoline-powered Silverado 2500HD models, the Duramax diesel offered superior towing performance and fuel efficiency, but at a higher initial cost. Compared to competitors such as the Ford Super Duty and Ram 2500, the Silverado 2500HD was often seen as a well-rounded and capable option, offering a compelling combination of power, refinement, and value.
Legacy
The Duramax LML engine and Allison 1000 transmission combination has proven to be exceptionally durable and reliable. Well-maintained examples of the 2015-2017 Silverado 2500HD continue to command strong resale values in the used car market. The engine is known for its longevity, with many examples exceeding 200,000 miles without major issues. However, potential buyers should be aware of the importance of regular maintenance, including oil changes and fuel filter replacements, to ensure long-term reliability. The K2XX platform Silverado 2500HD remains a popular choice for those seeking a capable and dependable heavy-duty truck.
