The Chevrolet Silverado 3500 HD III (K2XX) Crew 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 heavy-duty pickup truck produced by Chevrolet for the 2015 and 2016 model years. This variant occupied a significant position within the Silverado 3500 HD lineup, offering a balance between capability, fuel flexibility, and comfort for both work and personal use. It represented the third generation of the K2XX platform Silverado HD trucks, building upon the foundation of its predecessors with updated styling, technology, and enhanced towing capacity.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD III (K2XX) Crew 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%) | 4037 kg / 8900.06 lbs. |
| Length | 6563 mm / 258.39 in. |
| Width including mirrors | 2045 mm / 80.51 in. |
| Height | 1979 mm / 77.91 in. |
| Wheelbase | 4259 mm / 167.68 in. |
| Front track | 1748 mm / 68.82 in. |
| Rear (Back) track | 1709 mm / 67.28 in. |
| Ride height (ground clearance) | 214 mm / 8.43 in. |
| Minimum turning circle (turning diameter) | 17.1 m / 56.1 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, 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 |
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD variant lies the Vortec LC8 6.0-liter V8 engine. This engine is a member of Chevrolet’s Vortec family, known for its robust construction and reliable performance. The LC8 features a cast iron block and aluminum cylinder heads, incorporating a 9.6:1 compression ratio and a multi-port fuel injection system. The engine utilizes an overhead valve (OHV) valvetrain with variable valve timing (VVT) to optimize performance and fuel efficiency across a wider RPM range. The 301 horsepower and 333 lb-ft of torque were delivered to the rear wheels through a six-speed Hydra-Matic automatic transmission. The addition of CNG capability allowed operators to take advantage of potentially lower fuel costs and reduced emissions, though it required a dedicated CNG tank and fuel system.
Driving Characteristics
The 6.0L V8 with the automatic transmission provided a comfortable and capable driving experience, particularly suited for towing and hauling. While not as quick as some of the diesel-powered Silverado 3500 HD models, the gasoline engine offered smooth and predictable power delivery. The six-speed automatic transmission was well-matched to the engine’s torque curve, providing adequate gear ratios for both everyday driving and demanding tasks. Compared to the 6.6L Duramax diesel, this variant prioritized affordability and simplicity over outright towing capacity and fuel economy. The automatic transmission, while convenient, did result in a slight reduction in fuel efficiency compared to the available manual transmission options.
Equipment & Trim Levels
The Crew Cab Long Box configuration offered a spacious interior with seating for five passengers. Standard features typically included air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the LT and LTZ, added features like leather upholstery, heated seats, a premium audio system, navigation, and advanced safety technologies. The CNG-equipped models often included specific gauges and indicators to monitor the CNG fuel system. Options such as a sunroof, upgraded wheels, and various towing packages were also available.
Chassis & Braking
The Silverado 3500 HD III utilized a fully boxed frame for enhanced rigidity and durability. The front suspension featured an independent torsion bar setup with double wishbone components, while the rear suspension employed a traditional leaf spring design. This configuration provided a comfortable ride while maintaining excellent load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, assisted by an Anti-lock Braking System (ABS). The rear brakes were slightly smaller in diameter than the front brakes, reflecting the weight distribution of the truck.
Market Reception & Comparison
The 6.0L V8/automatic combination was generally well-received as a capable and affordable option within the Silverado 3500 HD lineup. Critics noted its smooth power delivery and comfortable ride, but also pointed out its lower fuel economy compared to the diesel alternatives. The CNG capability was seen as a positive feature for fleet operators and environmentally conscious buyers. Compared to the 6.6L Duramax diesel, this variant offered a lower initial cost but sacrificed towing capacity and fuel efficiency. Against the 6.0L gasoline engine with a manual transmission, the automatic provided added convenience but resulted in a slight performance and fuel economy penalty.
Legacy
The Chevrolet Silverado 3500 HD III (K2XX) with the 6.0L V8 and automatic transmission has proven to be a relatively reliable powertrain in the used car market. The Vortec LC8 engine is known for its durability, and the Hydra-Matic transmission is generally dependable when properly maintained. While not as sought after as the diesel models, these trucks offer a cost-effective entry point into the heavy-duty pickup truck segment. The CNG-equipped variants, while less common, can be attractive to buyers seeking alternative fuel options. Today, these trucks continue to be used for work and personal transportation, demonstrating their enduring capability and value.
