The Chevrolet Silverado 2500HD III (K2XX) Double Cab Standard Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 397 horsepower and paired with a 6-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 capabilities alongside a degree of refinement. It was part of the third generation of the K2XX platform, known for its increased strength and improved ride quality compared to its predecessors.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD III (K2XX) Double Cab Standard Box |
| Type (Engine) | 6.6 Duramax TD V8 (397 Hp) 4WD 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 | 7.9 kg/Hp, 125.9 Hp/tonne |
| Weight-to-torque ratio | 3 kg/Nm, 328.9 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 | 3153 kg (6951.18 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1383 kg (3048.99 lbs.) |
| Trunk (boot) space – maximum | 1728 l (61.02 cu. ft.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 5897 kg (13000.66 lbs.) |
| Length | 5841 mm (229.96 in.) |
| Width including mirrors | 2045 mm (80.51 in.) |
| Height | 1983 mm (78.07 in.) |
| Wheelbase | 3662 mm (144.17 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Ride height (ground clearance) | 216 mm (8.5 in.) |
| Minimum turning circle (turning diameter) | 15 m (49.21 ft.) |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| 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, 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 |
Powertrain & Engine Architecture
The heart of this Silverado 2500HD variant is the Duramax LML 6.6-liter turbocharged diesel V8. This engine represents a significant evolution of the Duramax design, incorporating a variable geometry turbocharger (VGT) for improved responsiveness and efficiency. The LML features a cast iron block and aluminum cylinder heads, contributing to its robust construction. The engine utilizes a high-pressure common rail fuel injection system, delivering fuel at extremely high pressures for optimized combustion. The overhead valve (OHV) valvetrain, while traditional, is known for its durability and simplicity. The Allison 1000 6-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 765 lb-ft of torque delivered by the Duramax engine and Allison transmission combination provide substantial performance. While not as quick accelerating as gasoline-powered trucks, the Silverado 2500HD excels in towing and hauling. The Allison transmission is programmed for smooth shifts and efficient power delivery, making it well-suited for both on-road cruising and off-road work. Compared to the 6.0L gasoline V8 option, the Duramax offers significantly more torque at lower RPMs, making it easier to pull heavy loads. Compared to the lighter-duty Silverado 1500 models, the 2500HD exhibits a more substantial feel, with a firmer ride due to its heavier-duty suspension. The automatic transmission, while convenient, doesn’t offer the same level of control as a manual transmission, particularly when descending steep grades with a heavy load.
Equipment & Trim Levels
The Double Cab Standard Box configuration typically came standard with features like air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the LT and High Country, added features like leather upholstery, heated and ventilated seats, a premium audio system, navigation, and advanced safety technologies. Optional extras included a sunroof, upgraded wheels, and various towing packages. The Standard Box length offered a balance between cargo capacity and maneuverability, making it a popular choice for both work and personal use.
Chassis & Braking
The Silverado 2500HD utilizes a fully boxed frame for increased rigidity and strength. The front suspension features an independent torsion bar setup with double wishbone control arms, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, optimized for heavy-duty load carrying. Braking duties are handled by ventilated disc brakes at all four corners, providing ample stopping power. An Anti-lock Braking System (ABS) is standard. The 4WD system allows for on-demand engagement of the front axle, providing enhanced traction in slippery conditions.
Market Reception & Comparison
The Duramax/Allison combination in the Silverado 2500HD was widely praised by automotive critics for its power, reliability, and fuel efficiency. While diesel engines typically command a higher price, the Silverado 2500HD offered a compelling value proposition for buyers who frequently tow or haul heavy loads. Compared to the gasoline-powered Silverado 2500HD, the Duramax variant offered significantly better fuel economy when towing, and a longer engine lifespan. The Ford Super Duty and Ram 2500/3500 were the primary competitors, each offering their own strengths and weaknesses. The Silverado 2500HD often stood out for its refined ride quality and user-friendly Allison transmission.
Legacy
The Duramax LML engine and Allison 1000 transmission have proven to be exceptionally durable and reliable powertrains. 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 ability to exceed 200,000 miles with proper maintenance. The K2XX platform established a new benchmark for heavy-duty truck construction, and the Duramax/Allison combination remains a popular choice for buyers seeking a powerful and dependable work truck. The 2015-2017 models represent a sweet spot in the K2XX generation, offering a balance of modern features and proven reliability.
