The Chevrolet Silverado 3500 HD III (K2XX) Crew Cab Long Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 397 horsepower and paired with a 4WD SRW Automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2015 to 2017, this variant occupied a premium position within the Silverado 3500 HD lineup, targeting buyers requiring substantial towing and hauling capabilities alongside a comfortable, well-equipped cabin. It was part of the third generation of the K2XX platform, known for its increased strength and refinement compared to its predecessors.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD III (K2XX) Crew Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (397 Hp) 4WD SRW 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 | 8.8 kg/Hp, 114.2 Hp/tonne |
| Weight-to-torque ratio | 3.4 kg/Nm, 298.4 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 | 29.7 l, 31.38 US qt | 26.13 UK qt |
| Kerb Weight | 3475 kg, 7661.06 lbs |
| Max. weight | 5262 kg, 11600.72 lbs |
| Max load | 1787 kg, 3939.66 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%) | 6804 kg, 15000.25 lbs |
| Length | 6563 mm, 258.39 in |
| Width including mirrors | 2045 mm, 80.51 in |
| Height | 1979 mm, 77.91 in |
| Wheelbase | 4259 mm, 167.68 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) | 17.1 m, 56.1 ft |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels permanently, and the front wheels are driven through an electrically or mechanically operated clutch if necessary. |
| Drive wheel | All wheel drive (4×4) |
| 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, 373×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 235/80 R17; 265/70 R18 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
INTRODUCTION
The 2015-2017 Chevrolet Silverado 3500 HD Crew Cab Long Box with the 6.6L Duramax diesel and Allison automatic transmission was a cornerstone of Chevrolet’s heavy-duty truck offerings. Built on the K2XX platform, introduced in 2014, this generation represented a significant leap forward in terms of capability, refinement, and interior space. The Crew Cab configuration provided ample room for passengers, while the Long Box offered a generous cargo bed. This particular variant, with its potent diesel engine and robust automatic transmission, was designed for owners who frequently tow large trailers, haul heavy loads, or require a powerful work truck with everyday usability.
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD lies the Duramax LML 6.6-liter turbocharged diesel V8 engine. This engine is renowned for its durability and impressive torque output. The LML featured a revised turbocharger, improved fuel injection system, and enhanced glow plug system compared to previous Duramax iterations. The engine utilizes a diesel commonrail fuel injection system, delivering highly pressurized fuel directly into the cylinders for efficient combustion. The overhead valve (OHV) valvetrain, while traditional, 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. It 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 everyday driving, providing a balance of power and efficiency.
Driving Characteristics
The Silverado 3500 HD 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 764.85 lb-ft of torque provide ample power for accelerating with a load or tackling steep grades. The Allison transmission shifts smoothly and decisively, providing confident power delivery. Compared to gasoline-powered Silverado 3500 HD models, the diesel offers significantly more low-end torque, making it ideal for towing. Compared to manual transmission equipped Duramax models, the automatic provides ease of use, particularly in stop-and-go traffic or for drivers less familiar with manual transmissions. However, some drivers may prefer the more direct control offered by a manual gearbox. The truck’s substantial weight and heavy-duty suspension contribute to a firm ride, but the Crew Cab configuration and well-insulated cabin minimize discomfort.
Equipment & Trim Levels
The Silverado 3500 HD III (K2XX) Crew Cab Long Box 6.6 Duramax TD V8 (397 Hp) 4WD SRW Automatic typically came well-equipped, though specific features varied depending on the chosen trim level (LT, LTZ). Standard features generally included air conditioning, power windows and locks, a rearview camera, and a basic infotainment system. Higher trim levels added features such as leather upholstery, heated and ventilated front seats, a premium audio system, navigation, and advanced safety technologies. Optional extras included a sunroof, upgraded wheels, and various towing packages. The interior design prioritized functionality and durability, with comfortable seating and intuitive controls.
Chassis & Braking
The K2XX platform chassis provided a solid foundation for the Silverado 3500 HD. The front suspension utilized an independent torsion bar and double wishbone setup, while the rear suspension employed a traditional leaf spring design. This configuration balanced ride comfort with load-carrying capacity. The braking system featured ventilated discs at all four corners, providing ample stopping power even when towing heavy loads. An Anti-lock Braking System (ABS) was standard. The truck’s robust frame and heavy-duty components were designed to withstand the stresses of demanding work applications.
Market Reception & Comparison
The Silverado 3500 HD with the Duramax diesel and Allison automatic received generally positive reviews from automotive critics. It was praised for its powerful engine, smooth transmission, and impressive towing capacity. Fuel economy, while not a primary concern for heavy-duty truck buyers, was considered respectable for a vehicle of its size and capability. Compared to the gasoline-powered Silverado 3500 HD models, the diesel variant commanded a higher price but offered significantly more torque and better fuel economy when towing. Compared to competitors like the Ford Super Duty and Ram Heavy Duty trucks, the Silverado 3500 HD was often seen as a strong contender, 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. Properly maintained, these powertrains can easily exceed 200,000 miles. On the used car market, the 2015-2017 Silverado 3500 HD with this powertrain configuration remains highly sought after, commanding a premium price compared to lower-trim models or those equipped with gasoline engines. Its reputation for reliability, combined with its impressive towing and hauling capabilities, ensures its continued popularity among truck enthusiasts and professionals alike. The K2XX platform laid the groundwork for future generations of Chevrolet heavy-duty trucks, continuing a legacy of strength and dependability.
