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 Dual Rear Wheel (DRW) automatic transmission, was a key offering in Chevrolet’s heavy-duty truck lineup from 2015 to 2017. This configuration represented a robust work truck option, positioned between the lighter-duty Silverado 2500 HD and the more specialized configurations of the 3500 HD line. It catered to owners needing substantial towing and payload capacity for commercial or demanding personal use. 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 3500 HD |
| Generation | Silverado 3500 HD III (K2XX) Regular Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (397 Hp) 4WD DRW 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 | 8.5 kg/Hp, 118.1 Hp/tonne |
| Weight-to-torque ratio | 3.2 kg/Nm, 308.4 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 | 22.4 l, 23.67 US qt | 19.71 UK qt |
| Kerb Weight | 3362 kg, 7411.94 lbs. |
| Max. weight | 5908 kg, 13024.91 lbs. |
| Max load | 2546 kg, 5612.97 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%) | 9072 kg, 20000.34 lbs. |
| Length | 5699 mm, 224.37 in. |
| Width including mirrors | 2438 mm, 95.98 in. |
| Height | 1967 mm, 77.44 in. |
| Wheelbase | 3393 mm, 133.58 in. |
| Front track | 1748 mm, 68.82 in. |
| Rear (Back) track | 1906 mm, 75.04 in. |
| Ride height (ground clearance) | 205 mm, 8.07 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, 355×40 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 |
Powertrain & Engine Architecture
The heart of this Silverado 3500 HD variant is the Duramax LML 6.6-liter turbocharged diesel V8. This engine, a staple of GM’s heavy-duty trucks, is known for its durability and substantial torque output. The LML iteration, introduced in 2011, featured a revised turbocharger, improved fuel injection system, and enhanced exhaust gas recirculation (EGR) system for increased efficiency and reduced emissions. The engine utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressure for optimal combustion. The overhead valve (OHV) valvetrain, while a more traditional design, contributes to the engine’s robustness and low-end torque characteristics. The Allison 1000 six-speed automatic transmission is specifically designed to handle the high torque output of the Duramax engine. It features a lock-up torque converter for improved fuel economy at highway speeds and heavy-duty internal components for reliability under demanding conditions.
Driving Characteristics
The 397 horsepower and 764.85 lb-ft of torque delivered by the Duramax engine and Allison transmission combination provide impressive towing and hauling capabilities. While not as quick accelerating as gasoline-powered trucks, the Silverado 3500 HD excels in situations requiring substantial pulling power. The automatic transmission offers smooth shifts, although it may occasionally hunt for the right gear when under heavy load. Compared to the 6.0-liter gasoline V8 option, the Duramax provides significantly more torque at lower RPMs, making it ideal for towing large trailers or hauling heavy payloads. The DRW configuration (Dual Rear Wheels) further enhances stability and load-carrying capacity. Compared to manual transmission equipped Duramax trucks, the automatic offers ease of use, particularly in stop-and-go traffic, but may result in a slight reduction in fuel economy.
Equipment & Trim Levels
The Silverado 3500 HD in this configuration typically came standard with features geared towards work truck functionality. This included vinyl upholstery, a basic audio system, air conditioning, and power windows and locks. The Regular Cab configuration prioritized interior space for work-related items rather than passenger comfort. Optional extras included upgraded audio systems, power-adjustable seats, a navigation system, and various towing packages. Higher trim levels, such as the LT and LTZ, offered more luxurious appointments, but the base model focused on providing a durable and capable work truck at a competitive price point.
Chassis & Braking
The K2XX platform chassis features a fully boxed frame for increased rigidity and strength. The front suspension utilizes an independent torsion bar setup with double wishbones, providing a comfortable ride even when unladen. The rear suspension employs a traditional leaf spring design, optimized for heavy-duty load carrying. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power even with a heavy load. An Anti-lock Braking System (ABS) is standard. The DRW configuration significantly increases the truck’s stability and braking effectiveness when towing or hauling.
Market Reception & Comparison
The Silverado 3500 HD with the Duramax diesel and Allison automatic was generally well-received by critics and consumers alike. It was praised for its robust powertrain, impressive towing capacity, and comfortable ride quality (for a heavy-duty truck). Fuel economy, while better than gasoline alternatives, was still relatively low, averaging around 17-20 MPG on the highway. Compared to the Ford Super Duty and Ram 3500, the Silverado 3500 HD offered a competitive combination of capability, comfort, and value. The Duramax engine was often cited as a key selling point, offering a balance of power, efficiency, and reliability.
Legacy
The Duramax LML engine paired with the Allison transmission has proven to be a remarkably durable powertrain. Properly maintained, these engines can easily exceed 200,000 miles. On the used car market, these Silverado 3500 HD models remain popular choices for those needing a capable and reliable heavy-duty truck. However, potential buyers should be aware of the higher maintenance costs associated with diesel engines, including the potential for issues with the fuel injection system, turbocharger, and emissions control systems. The K2XX platform Silverado 3500 HD represents a significant step forward in heavy-duty truck design, offering a blend of capability, comfort, and refinement that continues to appeal to buyers today.
