The Chevrolet Silverado 3500 HD III (K2XX) Double Cab Long Box, equipped with the 6.6-liter Duramax TD V8 engine producing 445 horsepower, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2017 to 2019, this variant occupied a premium position within the K2XX Silverado 3500 HD lineup, targeting buyers requiring substantial towing and hauling capabilities combined with a degree of comfort and refinement. It was a key player in the competitive North American heavy-duty truck market, directly challenging offerings from Ford and Ram.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD III (K2XX) Double Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (445 Hp) SRW Automatic |
| Start of production | 2017 |
| End of production | 2019 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.4 kg/Hp, 135.1 Hp/tonne |
| Weight-to-torque ratio | 2.7 kg/Nm, 374.7 Nm/tonne |
| Power | 445 Hp @ 2800 rpm |
| Power per litre | 67.4 Hp/l |
| Torque | 1234 Nm @ 1600 rpm (910.15 lb.-ft. @ 1600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax L5P |
| Engine displacement | 6604 cm3 (403 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 | 3293 kg (7259.82 lbs.) |
| Max. weight | 5080 kg (11199.48 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%) | 6577 kg (14499.8 lbs.) |
| Length | 6321 mm (248.86 in.) |
| Width including mirrors | 2045 mm (80.51 in.) |
| Height | 1981 mm (77.99 in.) |
| Wheelbase | 4017 mm (158.15 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Minimum turning circle (turning diameter) | 16.2 m (53.15 ft.) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine (ICE) drives the rear wheels. |
| 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 |
| Tires size | 235/80 R17; 265/70 R18 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
INTRODUCTION
The 2017-2019 Chevrolet Silverado 3500 HD Double Cab Long Box with the 6.6L Duramax diesel and Allison automatic transmission was a workhorse designed for serious tasks. Built on the K2XX platform, introduced in 2014, this generation represented a significant step forward in heavy-duty truck refinement. The Double Cab configuration offered increased passenger space compared to the standard cab, while the Long Box provided ample cargo capacity. This particular variant, with its potent diesel engine and automatic transmission, aimed to deliver a balance of power, capability, and usability for owners who frequently tow large trailers or haul heavy loads.
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD lies the Duramax L5P 6.6-liter turbocharged diesel V8. This engine is a testament to modern diesel technology, featuring a cast iron block, aluminum cylinder heads, and a robust rotating assembly. The L5P utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The turbocharger, coupled with an intercooler, provides increased air density for enhanced power output. The engine produces 445 horsepower at 2800 rpm and a massive 910 lb-ft (1234 Nm) of torque at 1600 rpm. The Allison 1000 Series six-speed automatic transmission is specifically designed to handle the high torque output of the Duramax engine. This transmission features electronically controlled shifts and a lock-up torque converter for improved fuel efficiency. The OHV valvetrain, while traditional, is known for its durability and reliability in heavy-duty applications.
Driving Characteristics
The Silverado 3500 HD 6.6L Duramax with the Allison automatic delivers a driving experience focused on capability rather than outright speed. The substantial torque output allows for effortless towing and hauling, even with significant loads. The Allison transmission provides smooth and predictable shifts, although it isn’t as quick-shifting as some newer transmissions. Compared to the 6.0L gasoline V8 option, the Duramax offers significantly more low-end torque, making it ideal for demanding tasks. While a manual transmission was available on other Silverado 3500 HD trims, the Allison automatic was favored by many for its ease of use, especially when towing. The gear ratios are optimized for pulling power, meaning acceleration is brisk but not sporty. The truck feels planted and stable, even when fully loaded, thanks to its heavy-duty suspension and robust chassis.
Equipment & Trim Levels
The Silverado 3500 HD Double Cab Long Box 6.6 Duramax typically came standard with features like air conditioning, power windows and locks, a basic infotainment system, and a rearview camera. Higher trim levels, such as LTZ and High Country, added luxury features like leather upholstery, heated and ventilated seats, a premium sound system, and advanced safety technologies. Optional extras included a navigation system, a sunroof, and various towing packages. The interior design was functional and durable, prioritizing practicality over lavishness. The Double Cab configuration offered comfortable seating for five passengers, making it suitable for both work and family use.
Chassis & Braking
The K2XX chassis is a fully boxed frame designed for maximum strength and rigidity. 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, with larger rotors at the front. An Anti-lock Braking System (ABS) is standard. The rear axle is a solid axle, contributing to the truck’s robust towing capabilities. Stabilizer bars were included to reduce body roll during cornering, although the truck’s high center of gravity still results in noticeable body lean.
Market Reception & Comparison
The Silverado 3500 HD 6.6L Duramax 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 acceptable for a vehicle of its size and capability. Compared to the Ford Super Duty and Ram 3500, the Silverado 3500 HD was often seen as offering a good balance of value and performance. The Duramax engine was consistently ranked among the best diesel engines in the heavy-duty truck segment. Some critics noted that the interior design was less luxurious than some competitors, but the Silverado’s overall functionality and reliability were highly regarded.
Legacy
The Duramax L5P engine and Allison transmission pairing has proven to be exceptionally durable and reliable. These trucks continue to hold their value well in the used car market, particularly those that have been well-maintained. The L5P Duramax is known for its longevity and ability to withstand high mileage. While diesel engines generally require more expensive maintenance than gasoline engines, the Duramax’s robust construction minimizes the risk of major failures. The 2017-2019 Silverado 3500 HD 6.6L Duramax remains a popular choice for buyers seeking a capable and dependable heavy-duty truck, solidifying its place as a significant vehicle in Chevrolet’s history.
