The Chevrolet Silverado 2500 HD III (K2XX) Double Cab Long Box, specifically equipped with the 6.0-liter V8 engine producing 301 horsepower and paired with an automatic transmission, and capable of running on Compressed Natural Gas (CNG), was a work-focused trim offered for the 2015 and 2016 model years. This variant occupied a mid-range position within the Silverado 2500 HD lineup, offering a balance between capability, fuel flexibility, and cost. It was designed to appeal to commercial users and individuals requiring substantial towing and hauling capacity, while also seeking an alternative fuel option. The K2XX platform represented the third generation of the Silverado HD series, introducing significant improvements in strength, refinement, and technology compared to its predecessors.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD III (K2XX) Double Cab Long Box |
| Type (Engine) | 6.0 V8 (301 Hp) Automatic CNG |
| Start of production | 2015 |
| End of production | 2016 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol / CNG |
| Power | 301 Hp @ 5000 rpm |
| Power per litre | 50.4 Hp/l |
| Torque | 452 Nm @ 4200 rpm / 333.38 lb.-ft. @ 4200 rpm |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Vortec LC8 |
| Engine displacement | 5967 cm3 / 364.13 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 101.6 mm / 4 in. |
| Piston Stroke | 92 mm / 3.62 in. |
| Compression ratio | 9.6:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV, VVT |
| Engine oil capacity | 5.7 l / 6.02 US qt | 5.02 UK qt |
| Coolant | 15.5 l / 16.38 US qt | 13.64 UK qt |
| Fuel tank capacity | 136 l / 35.93 US gal | 29.92 UK gal |
| CNG cylinder capacity | 67 kg |
| Permitted trailer load with brakes (12%) | 5897 kg / 13000.66 lbs. |
| Length | 6321 mm / 248.86 in. |
| Width including mirrors | 2045 mm / 80.51 in. |
| Height | 1978 mm / 77.87 in. |
| Wheelbase | 4017 mm / 158.15 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) | 16.2 m / 53.15 ft. |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission Hydra-Matic |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 350×40 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 |
INTRODUCTION
The Chevrolet Silverado 2500HD III, produced from 2015 to 2016, represented a significant step forward in heavy-duty truck design. The K2XX platform brought increased rigidity and improved interior space. The 6.0L V8 with CNG capability was a specific configuration aimed at fleet and cost-conscious buyers looking for an alternative to diesel power, while still maintaining substantial towing and hauling capabilities. This Double Cab Long Box configuration offered a practical balance between passenger space and cargo bed length, making it suitable for both work and family use. The addition of CNG capability allowed operators to take advantage of potentially lower fuel costs and reduced emissions, depending on local CNG infrastructure and pricing.
Powertrain & Engine Architecture
At the heart of this Silverado 2500HD variant lies the Vortec LC8 6.0-liter V8 engine. This engine is a naturally aspirated, overhead valve (OHV) design featuring variable valve timing (VVT) for improved efficiency and performance. The LC8 utilizes multi-port fuel injection, delivering fuel directly into the intake ports. The engine produces 301 horsepower at 5000 rpm and 452 Nm (333.38 lb-ft) of torque at 4200 rpm. The engine’s robust construction and relatively simple design contribute to its reliability. The Hydra-Matic 6L90 six-speed automatic transmission was the sole transmission option for this configuration. This transmission is known for its durability and smooth shifting characteristics, and its gear ratios are optimized for towing and hauling. The CNG system is a bi-fuel setup, meaning the truck can seamlessly switch between gasoline and CNG, extending its range and providing fuel flexibility.
Driving Characteristics
The 6.0L V8/automatic combination in the Silverado 2500HD delivers adequate, though not exceptional, performance. Compared to the available Duramax diesel engine, the 6.0L offers less torque, resulting in slower acceleration and reduced towing capacity. However, it provides a smoother and quieter driving experience than the diesel. The Hydra-Matic 6L90 transmission shifts smoothly and provides sufficient gear ratios for most driving situations. The gear ratios are tuned for maximizing torque at lower speeds, aiding in towing and hauling. While the diesel-powered models excel in heavy-duty applications, the 6.0L CNG variant is well-suited for lighter-duty tasks and everyday driving. The CNG system doesn’t significantly impact performance when running on CNG, but it does reduce the overall range compared to gasoline-only operation.
Equipment & Trim Levels
The Silverado 2500HD Double Cab Long Box 6.0L CNG typically came standard with features such as air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the LT, added features like cloth or leather upholstery, a more advanced audio system, and additional convenience features. Optional extras included a navigation system, a rearview camera, and various towing packages. The CNG system itself was a factory-installed option, integrated seamlessly into the vehicle’s fuel system. The interior design was functional and durable, prioritizing practicality over luxury. The Double Cab configuration provided comfortable seating for five passengers, while the Long Box offered ample cargo space.
Chassis & Braking
The Silverado 2500HD features a robust chassis designed to withstand heavy loads. The front suspension utilizes an independent torsion bar and double wishbone setup, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, offering excellent load-carrying capacity. Brakes are ventilated discs on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) is standard. The steering system is a cone worm with recirculation balls, offering a direct and responsive feel. The tires are typically sized 245/75 R17, 265/70 R17, 265/70 R18, or 265/60 R20, depending on the trim level and wheel size.
Market Reception & Comparison
The Silverado 2500HD 6.0L CNG variant received mixed reviews. Critics praised its fuel flexibility and potential cost savings with CNG, but noted its lower performance compared to the diesel models. Fuel economy was comparable to other gasoline-powered heavy-duty trucks, but the availability of CNG infrastructure was a limiting factor for many buyers. Compared to the 6.6L Duramax diesel, the 6.0L offered significantly less towing capacity and lower fuel efficiency when running on gasoline. However, it was generally more affordable to purchase and maintain. The 6.0L CNG variant appealed to buyers who prioritized fuel cost savings and environmental considerations over outright performance.
Legacy
The Silverado 2500HD 6.0L CNG variant represents a unique offering in the heavy-duty truck market. While not as popular as the diesel-powered models, it provided a viable alternative for buyers seeking a fuel-flexible and cost-effective work truck. The Vortec LC8 engine is known for its reliability, and the Hydra-Matic 6L90 transmission is a durable and dependable unit. In the used car market, these trucks are generally well-regarded for their durability and practicality. However, the availability of CNG fueling stations remains a key consideration for potential buyers. The K2XX platform proved to be a successful design, laying the foundation for future generations of Silverado HD trucks.
