The Mercedes-Benz CLS 400 V6 (333 hp) with the 9G-TRONIC automatic transmission represents a significant iteration of the C218 facelifted CLS-Class, produced from April 2016 to December 2017. Positioned as a mid-range offering within the CLS lineup, it bridged the gap between the entry-level CLS 350 and the performance-oriented AMG variants. This model aimed to deliver a blend of luxury, performance, and efficiency, appealing to buyers seeking a stylish four-door coupe experience. The C218 generation, introduced in 2010, pioneered the “four-door coupe” segment, and the facelift in 2014 refined the design and introduced updated technology, with the CLS 400 becoming a key part of the revised range.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | CLS |
| Generation | CLS coupe (C218 facelift, 2014) |
| Type (Engine) | CLS 400 V6 (333 Hp) 9G-TRONIC |
| Start of production | April, 2016 |
| End of production | December, 2017 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 4 |
| Fuel consumption (economy) – urban (NEDC) | 10.3-10.4 l/100 km (22.8 – 22.6 US mpg, 27.4 – 27.2 UK mpg, 9.7 – 9.6 km/l) |
| Fuel consumption (economy) – extra urban (NEDC) | 5.7-5.9 l/100 km (41.3 – 39.9 US mpg, 49.6 – 47.9 UK mpg, 17.5 – 16.9 km/l) |
| Fuel consumption (economy) – combined (NEDC) | 7.4-7.5 l/100 km (31.8 – 31.4 US mpg, 38.2 – 37.7 UK mpg, 13.5 – 13.3 km/l) |
| CO2 emissions (NEDC) | 166-169 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.4 sec |
| Acceleration 0 – 62 mph | 5.4 sec |
| Acceleration 0 – 60 mph | 5.1 sec |
| Maximum speed | 250 km/h (155.34 mph), Electronically limited |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 5.1 kg/Hp, 195.9 Hp/tonne |
| Weight-to-torque ratio | 3.5 kg/Nm, 282.4 Nm/tonne |
| Power | 333 Hp @ 5250-6000 rpm |
| Power per litre | 95.2 Hp/l |
| Torque | 480 Nm @ 1200-4000 rpm (354.03 lb.-ft. @ 1200-4000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 276.850 |
| Engine displacement | 3498 cm3 (213.46 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Cylinder Bore | 92.9 mm (3.66 in.) |
| Piston Stroke | 86 mm (3.39 in.) |
| Compression ratio | 10.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | BiTurbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Coolant | 9.6 l (10.14 US qt | 8.45 UK qt) |
| Kerb Weight | 1700 kg (3747.86 lbs.) |
| Max. weight | 2260 kg (4982.45 lbs.) |
| Max load | 560 kg (1234.59 lbs.) |
| Trunk (boot) space – minimum | 520 l (18.36 cu. ft.) |
| Fuel tank capacity | 59 l (15.59 US gal | 12.98 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Length | 4937 mm (194.37 in.) |
| Width | 1881 mm (74.06 in.) |
| Width including mirrors | 2075 mm (81.69 in.) |
| Height | 1418 mm (55.83 in.) |
| Wheelbase | 2874 mm (113.15 in.) |
| Front track | 1596 mm (62.83 in.) |
| Rear (Back) track | 1626 mm (64.02 in.) |
| Front overhang | 898 mm (35.35 in.) |
| Rear overhang | 1165 mm (45.87 in.) |
| Minimum turning circle (turning diameter) | 11.18 m (36.68 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 | 9 gears, automatic transmission G-TRONIC |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
Powertrain & Engine Architecture
The CLS 400 V6 utilizes Mercedes-Benz’s M276.850 engine, a 3.5-liter (3498 cc) V6 engine. This engine is characterized by its direct injection, twin-turbocharger setup, and multi-spark ignition. The twin-turbochargers, one for each bank of cylinders, provide a broad torque curve and responsive power delivery. The engine produces 333 horsepower at 5250-6000 rpm and 480 Nm (354 lb-ft) of torque between 1200-4000 rpm. The 9G-TRONIC nine-speed automatic transmission is a key component, offering a wide range of gear ratios to optimize fuel efficiency and performance. This transmission features a high gear ratio spread, allowing for both relaxed cruising at low engine speeds and quick acceleration when needed. The transmission also incorporates a torque converter lockup clutch to minimize slippage and improve efficiency.
Driving Characteristics
The CLS 400 V6 with the 9G-TRONIC provides a refined and comfortable driving experience. Acceleration from 0 to 60 mph takes approximately 5.1 seconds, making it a reasonably quick vehicle. The 9G-TRONIC transmission shifts smoothly and efficiently, contributing to a relaxed driving experience during normal cruising. Compared to the CLS 350, the 400 offers noticeably more power and quicker acceleration. While not as aggressively tuned as the AMG variants, the CLS 400 provides ample power for overtaking and spirited driving. The gear ratios are well-chosen, providing strong acceleration in most situations. The engine delivers a consistent and linear power delivery, making it easy to modulate throttle response.
Equipment & Trim Levels
The CLS 400 V6 typically came standard with a high level of equipment, reflecting its positioning as a luxury vehicle. Standard features included leather upholstery, automatic climate control, a premium sound system, and a comprehensive suite of safety features, including adaptive cruise control, lane keeping assist, and automatic emergency braking. Optional extras included a panoramic sunroof, upgraded leather packages, wood trim options, and a head-up display. The interior design featured a blend of elegant materials and modern technology, with a focus on comfort and refinement. The dashboard layout was clean and intuitive, with a central display screen controlling many of the vehicle’s functions.
Chassis & Braking
The CLS 400 V6 features a sophisticated chassis design aimed at providing a balance of comfort and handling. The front suspension utilizes a multi-link setup with coil springs, while the rear suspension employs an independent multi-link spring suspension. Air suspension was available as an option, further enhancing ride comfort and allowing for adjustable ride height. The braking system consists of ventilated discs on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) and electronic stability control (ESC) are standard features, enhancing safety and stability. The steering system is a rack-and-pinion setup with electric power steering, offering precise and responsive steering feel.
Market Reception & Comparison
The CLS 400 V6 was generally well-received by automotive critics. It was praised for its refined driving experience, luxurious interior, and efficient powertrain. Compared to the CLS 350, the 400 offered a significant performance upgrade without the higher price tag of the AMG models. Fuel economy was considered respectable for a vehicle of its size and performance, with combined fuel consumption figures ranging from 7.4 to 7.5 l/100 km (31.8-31.4 US mpg). Reliability reports suggest that the M276 engine is generally reliable, although preventative maintenance is crucial. Some owners have reported issues with the air suspension system (if equipped), and the complex electronic systems can occasionally require attention.
Legacy
The Mercedes-Benz CLS 400 V6 (C218) remains a desirable vehicle in the used car market. Its combination of style, performance, and luxury continues to appeal to buyers seeking a distinctive four-door coupe. The M276 engine, while complex, has proven to be relatively durable with proper maintenance. The 9G-TRONIC transmission is also generally reliable, contributing to the long-term ownership appeal of this model. The CLS 400 represents a sweet spot in the C218 lineup, offering a compelling blend of attributes that make it a worthwhile consideration for those seeking a sophisticated and capable luxury vehicle.
