The Chevrolet Silverado 3500 HD III (K2XX) Regular 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 configuration occupied a prominent position within the K2XX generation, catering to buyers requiring substantial towing and hauling capabilities. It was designed to be a workhorse, appealing to commercial users, farmers, and individuals with demanding needs, while still offering a degree of comfort and refinement expected in a modern pickup truck.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD III (K2XX) Regular 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 | 2 |
| Doors | 2 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 8 kg/Hp, 124.3 Hp/tonne |
| Weight-to-torque ratio | 3.1 kg/Nm, 324.8 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 | 3193 kg, 7039.36 lbs. |
| Max. weight | 5171 kg, 11400.1 lbs. |
| Max load | 1978 kg, 4360.74 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 | 1979 mm, 77.91 in. |
| Wheelbase | 3393 mm, 133.58 in. |
| Front track | 1748 mm, 68.82 in. |
| Rear (Back) track | 1709 mm, 67.28 in. |
| Ride height (ground clearance) | 220 mm, 8.66 in. |
| Minimum turning circle (turning diameter) | 14 m, 45.93 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, specifically the Regular Cab Long Box configuration with the 6.6L Duramax diesel and Allison automatic, was a cornerstone of Chevrolet’s heavy-duty truck offerings. Built on the K2XX platform, introduced in 2014, this generation represented a significant step forward in terms of capability, refinement, and technology. The Regular Cab/Long Box combination was geared towards maximizing cargo space and utility, making it a popular choice for commercial applications and owners who frequently towed large trailers. This particular variant, with its potent diesel engine and robust transmission, was positioned as a premium offering within the 3500 HD lineup, exceeding the capabilities of the gasoline-powered options.
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 its predecessor, the LLY. The engine utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressures for optimal combustion efficiency. 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 a critical component of this powertrain. Known for its strength and smoothness, the Allison transmission is specifically designed to handle the high torque output of the Duramax engine. It features a lock-up torque converter for improved fuel efficiency at highway speeds and utilizes a heavy-duty cooling system to prevent overheating during demanding use.
Driving Characteristics
The Silverado 3500 HD with the Duramax/Allison combination delivers a driving experience focused on capability and control. While not a performance-oriented truck, the 397 horsepower and, more importantly, the 764.85 lb-ft of torque provide effortless towing and hauling. The Allison transmission’s gear ratios are optimized for both low-speed pulling power and comfortable highway cruising. Compared to the 6.0L gasoline V8 or the 6.6L gasoline V8 options, the Duramax diesel offers significantly more torque, resulting in a much more confident and capable towing experience. The automatic transmission, while smooth, doesn’t offer the same level of driver engagement as a manual transmission, but it simplifies operation, especially in heavy traffic or when towing. The truck’s substantial weight and heavy-duty suspension contribute to a firm ride, but it’s a trade-off necessary for its intended purpose.
Equipment & Trim Levels
The Silverado 3500 HD Regular Cab Long Box with the Duramax diesel typically came standard with features like air conditioning, power windows and locks, and a basic audio system. Higher trim levels, such as LT and LTZ, added features like leather upholstery, heated seats, a premium audio system, navigation, and advanced safety technologies. The interior design was functional and durable, prioritizing practicality over luxury. Optional extras included a trailer brake controller, a fifth-wheel hitch, and various bed accessories. The Regular Cab configuration offered a no-frills interior focused on maximizing workspace and utility.
Chassis & Braking
The Silverado 3500 HD’s chassis is built for heavy-duty use. It features a fully boxed frame constructed from high-strength steel. The front suspension utilizes an independent torsion bar setup with double wishbones, 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 on all four wheels, providing ample stopping power even when towing heavy loads. An Anti-lock Braking System (ABS) is standard. The truck’s robust chassis and braking system are designed to handle the stresses of frequent heavy hauling and towing.
Market Reception & Comparison
The Duramax diesel/Allison automatic combination was widely praised by automotive critics for its exceptional towing and hauling capabilities. Fuel economy, while not a primary concern for heavy-duty truck buyers, was respectable for a vehicle of this size and capability. Compared to the gasoline-powered Silverado 3500 HD models, the diesel offered significantly better fuel economy when towing. Reliability was generally good, although the Duramax engine’s complex emissions system could be prone to issues over time. The Silverado 3500 HD competed directly with the Ford Super Duty and Ram Heavy Duty trucks, and the Duramax/Allison combination was often considered a competitive advantage for Chevrolet.
Legacy
The 2015-2017 Chevrolet Silverado 3500 HD with the 6.6L Duramax diesel and Allison automatic remains a popular choice in the used truck market. The Duramax engine is known for its longevity, and well-maintained examples can provide many years of reliable service. However, potential buyers should be aware of the potential for emissions system issues and the cost of repairs. The truck’s robust construction and proven powertrain make it a valuable asset for anyone needing a capable and dependable heavy-duty truck. Its reputation for durability and towing prowess continues to solidify its place as a workhorse in the American trucking landscape.
