The Chevrolet Impala X 3.6 V6 (260/230 Hp) CNG Automatic, produced from 2015 to 2017, represented a unique offering within the tenth generation of the Impala (2014-2020). This variant was positioned as a mid-range option, appealing to buyers seeking a full-size sedan with the flexibility of both gasoline and Compressed Natural Gas (CNG) operation. It was part of the larger Impala X series, which aimed to provide a balance of comfort, technology, and efficiency in the American full-size sedan segment. The Impala X, built on the GM Epsilon II platform, was primarily marketed towards families and commuters looking for a spacious and reliable vehicle.
Technical Specifications
| Brand | Chevrolet |
| Model | Impala |
| Generation | Impala X |
| Type (Engine) | 3.6 V6 (260/230 Hp) CNG Automatic |
| Start of production | 2015 year |
| End of production | 2017 year |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol / CNG |
| Weight-to-power ratio | 7.3 kg/Hp, 137.3 Hp/tonne |
| Weight-to-torque ratio | 5.7 kg/Nm, 176.9 Nm/tonne |
| Power | 260 Hp @ 4800 rpm |
| Power per litre | 73.1 Hp/l |
| Power (CNG) | 230 Hp @ 4800 rpm |
| Power per litre (CNG) | 64.7 Hp/l |
| Torque | 335 Nm @ 4800 rpm |
| Torque (CNG) | 295 Nm @ 4800 rpm |
| Engine layout | Front, Transverse |
| Engine Model/Code | LFX |
| Engine displacement | 3556 cm3 |
| Engine displacement (US) | 217 cu. in. |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Cylinder Bore | 94 mm |
| Cylinder Bore (US) | 3.7 in. |
| Piston Stroke | 85.6 mm |
| Piston Stroke (US) | 3.37 in. |
| Compression ratio | 11.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | DOHC |
| Engine oil capacity | 5.7 l |
| Engine oil capacity (US) | 6.02 US qt | 5.02 UK qt |
| Coolant | 9.4 l |
| Coolant (US) | 9.93 US qt | 8.27 UK qt |
| Kerb Weight | 1894 kg |
| Kerb Weight (US) | 4175.56 lbs |
| Trunk (boot) space – minimum | 283 l |
| Trunk (boot) space – minimum (US) | 9.99 cu. ft. |
| Length | 5113 mm |
| Length (US) | 201.3 in. |
| Width | 1854 mm |
| Width (US) | 72.99 in. |
| Height | 1496 mm |
| Height (US) | 58.9 in. |
| Wheelbase | 2837 mm |
| Wheelbase (US) | 111.69 in. |
| Front track | 1580 mm |
| Front track (US) | 62.2 in. |
| Rear (Back) track | 1576 mm |
| Rear (Back) track (US) | 62.05 in. |
| Minimum turning circle (turning diameter) | 11.75 m |
| Minimum turning circle (turning diameter) (US) | 38.55 ft. |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the front wheels of the vehicle. |
| Drive wheel | Front wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission |
| Front suspension | Independent, type McPherson with coil spring and anti-roll bar |
| Rear suspension | Independent multi-link spring suspension with stabilizer |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 235/50 R18; 245/45 R19; 245/40 R20 |
| Wheel rims size | 18; 19; 20 |
Powertrain & Engine Architecture
At the heart of the Impala X 3.6 V6 CNG was the LFX engine, a 3.6-liter naturally aspirated V6. This engine featured a 60-degree V-angle and utilized an aluminum block and cylinder heads to reduce weight. The LFX employed multi-port fuel injection and a double overhead camshaft (DOHC) valvetrain with four valves per cylinder, contributing to its respectable power output. The engine was designed to run on both gasoline and CNG, with a dedicated fuel system for each. When operating on CNG, the engine management system adjusted parameters to optimize combustion for the alternative fuel, resulting in a slight reduction in horsepower (230 hp on CNG versus 260 hp on gasoline). The six-speed automatic transmission, a common GM unit, was calibrated to provide smooth shifts and efficient power delivery. The transmission’s gear ratios were tuned for comfortable cruising and adequate acceleration, though it wasn’t geared for outright performance.
Driving Characteristics
The Impala X 3.6 V6 Automatic offered a comfortable and composed driving experience. The 260 horsepower engine provided adequate acceleration for everyday driving situations, with a 0-60 mph time estimated around 7.5 seconds. However, it wasn’t a particularly sporty vehicle. The automatic transmission, while smooth, could feel somewhat hesitant during quick overtaking maneuvers. Switching to CNG resulted in a noticeable decrease in power, making the vehicle feel slightly more sluggish. The suspension, tuned for comfort, absorbed bumps and road imperfections well, providing a smooth ride. Steering was light and precise, making it easy to maneuver in city traffic. The front-wheel-drive configuration offered predictable handling, but lacked the dynamic capabilities of rear-wheel-drive or all-wheel-drive systems.
Equipment & Trim Levels
The Impala X 3.6 V6 CNG Automatic typically came standard with features such as keyless entry, a rearview camera, an 8-inch touchscreen infotainment system with Apple CarPlay and Android Auto compatibility, and a six-speaker audio system. Higher trim levels offered upgrades like leather upholstery, heated front seats, a premium Bose audio system, and advanced safety features like lane departure warning and forward collision alert. The interior design was modern and spacious, with comfortable seating and ample legroom for both front and rear passengers. Available options included a sunroof, navigation system, and a rear-seat entertainment system.
Chassis & Braking
The Impala X featured an independent suspension system at all four corners. The front suspension utilized a McPherson strut design with coil springs and an anti-roll bar, while the rear suspension employed a multi-link setup with a stabilizer bar. This configuration provided a good balance of ride comfort and handling stability. Braking duties were handled by ventilated discs at the front and solid discs at the rear. The anti-lock braking system (ABS) was standard, enhancing safety during emergency braking situations. The steering system was an electric power-assisted rack-and-pinion setup, offering light and precise steering feel.
Market Reception & Comparison
The Impala X 3.6 V6 CNG Automatic received mixed reviews. Critics praised its spacious interior, comfortable ride, and fuel efficiency when running on CNG. However, some found the engine to be underpowered, especially when operating on gasoline, and the automatic transmission lacked responsiveness. Compared to other Impala trims, such as the 2.5L four-cylinder model, the V6 offered significantly more power and a smoother driving experience. However, the V6 CNG variant was more expensive and offered a more complex powertrain. Compared to competitors like the Toyota Avalon and Ford Taurus, the Impala X offered a competitive level of features and value.
Legacy
The Chevrolet Impala X 3.6 V6 CNG Automatic represents an interesting chapter in the Impala’s history, showcasing GM’s efforts to offer alternative fuel options to consumers. While the CNG variant didn’t achieve widespread popularity, it provided a viable option for those seeking to reduce their reliance on gasoline. The LFX V6 engine proved to be a reliable and durable powerplant, and the six-speed automatic transmission generally held up well over time. Today, these Impalas can be found on the used car market at relatively affordable prices. Their long-term reliability is generally good, but potential buyers should be aware of the added complexity of the CNG system and ensure it is properly maintained.
