The Mercedes-Benz CLS 550 V8 (C218), produced from 2011 to 2014, represents a compelling blend of luxury, performance, and technology within the broader CLS coupe (C218) generation. Positioned as the range-topping engine option at its introduction, the CLS 550 aimed to deliver a more potent experience than the CLS 350 models, while offering a different character than the later AMG variants. It served as a flagship for non-AMG performance within the CLS lineup, appealing to buyers seeking substantial power and refinement in a stylish four-door coupe package. The C218 CLS was a significant model for Mercedes-Benz, pioneering the “four-door coupe” segment and establishing a new aesthetic that influenced subsequent designs.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | CLS |
| Generation | CLS coupe (C218) |
| Type | CLS 550 V8 (402 Hp) 7G-TRONIC PLUS |
| Start of production | 2011 |
| End of production | 2014 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 4 |
| Fuel consumption (urban) | 13.1-13.8 l/100 km (18-17 US mpg) |
| Fuel consumption (extra urban) | 8.7-9 l/100 km (27-26.1 US mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 60 mph | 5.1 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Weight-to-power ratio | 4.7 kg/Hp |
| Weight-to-torque ratio | 3.1 kg/Nm |
| Power | 402 Hp @ 5000-5750 rpm |
| Power per litre | 86.2 Hp/l |
| Torque | 600 Nm @ 1600-4750 rpm (442.54 lb.-ft.) |
| Maximum engine speed | 6300 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 278.922 |
| Engine displacement | 4663 cm3 (284.55 cu. in.) |
| Number of cylinders | 8 |
| 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 | 8 l (8.45 US qt | 7.04 UK qt) |
| Coolant capacity | 12.3 l (13 US qt | 10.82 UK qt) |
| Kerb Weight | 1886-1891 kg (4157.92 – 4168.94 lbs.) |
| Max. weight | 2371-2376 kg (5227.16 – 5238.18 lbs.) |
| Max load | 485 kg (1069.24 lbs.) |
| Trunk (boot) space | 520 l (18.36 cu. ft.) |
| Fuel tank capacity | 80 l (21.13 US gal | 17.6 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Length | 4940 mm (194.49 in.) |
| Width | 1881 mm (74.06 in.) |
| Width including mirrors | 2075 mm (81.69 in.) |
| Height | 1404-1418 mm (55.28 – 55.83 in.) |
| Wheelbase | 2874 mm (113.15 in.) |
| Front track | 1596-1598 mm (62.83 – 62.91 in.) |
| Rear track | 1624-1628 mm (63.94 – 64.09 in.) |
| Front overhang | 901 mm (35.47 in.) |
| Rear overhang | 1165 mm (45.87 in.) |
| Minimum turning circle | 11.27 m (36.98 ft.) |
| Drivetrain | Rear wheel drive |
| Number of gears | 7 |
| Gearbox type | Automatic transmission G-TRONIC PLUS |
| Front suspension | Independent multi-link suspension, Transverse stabilizer, Air suspension |
| Rear suspension | Independent multi-link suspension, Air suspension, Transverse stabilizer |
| Front brakes | Ventilated discs, 360×36 mm |
| Rear brakes | Ventilated discs, 320×24 mm |
| Steering type | Steering rack and pinion |
| Power steering | Electric |
| Tires size (Front) | 255/40 R18 |
| Tires size (Rear) | 285/35 R18 |
| Wheel rims size (Front) | 8.5J x 18 |
| Wheel rims size (Rear) | 9.5J x 18 |
INTRODUCTION
The Mercedes-Benz CLS 550 V8 (C218) debuted in 2011 as a mid-cycle refresh of the first-generation CLS. Building upon the original’s groundbreaking design, the C218 offered enhanced refinement, updated technology, and a more powerful engine option in the form of the M278 4.7-liter twin-turbocharged V8. This engine replaced the naturally aspirated 5.5-liter V8 found in earlier CLS models, providing increased horsepower and torque while improving fuel efficiency. The CLS 550 occupied a unique position in the Mercedes-Benz lineup, bridging the gap between the more comfort-oriented E-Class and the high-performance AMG models. It was designed to appeal to buyers who desired a luxurious and sporty grand tourer with a distinctive style.
Powertrain & Engine Architecture
At the heart of the CLS 550 lies the M278.922 4.7-liter V8 engine. This engine is a marvel of modern engineering, featuring direct fuel injection, twin turbochargers, and a sophisticated valvetrain. The direct injection system precisely meters fuel into the combustion chambers, optimizing combustion efficiency and reducing emissions. The twin turbochargers, strategically positioned within the V of the engine, provide instant boost and a broad torque curve. The engine utilizes a DOHC (Dual Overhead Camshaft) valvetrain with variable valve timing, further enhancing performance and efficiency. The 7G-TRONIC PLUS seven-speed automatic transmission is the sole transmission option for the CLS 550. This transmission is known for its smooth and responsive shifts, contributing to a refined driving experience. It features a torque converter lock-up clutch that engages at higher speeds to improve fuel economy. The engine’s layout is front-mounted and longitudinal, driving the rear wheels.
Driving Characteristics
The CLS 550 V8 delivers a compelling driving experience characterized by effortless power and refined handling. The 402 horsepower and 442 lb-ft of torque provide brisk acceleration, with a 0-60 mph time of around 5.1 seconds. The twin-turbochargers eliminate turbo lag, providing immediate throttle response. The 7G-TRONIC PLUS transmission seamlessly shifts through the gears, maintaining optimal engine speed for acceleration or cruising. Compared to the CLS 350, the 550 offers a significantly more engaging driving experience, with noticeably stronger acceleration and a more confident feel. While not as overtly sporty as the AMG variants, the CLS 550 provides a satisfying balance of performance and comfort. The air suspension contributes to a smooth and controlled ride, even over uneven surfaces.
Equipment & Trim Levels
The CLS 550 came standard with a comprehensive array of luxury features, including leather upholstery, wood trim, a premium sound system, and a navigation system. Standard equipment also included features like dual-zone automatic climate control, power-adjustable front seats with memory function, and a sunroof. Optional extras included a rear-seat entertainment system, a panoramic sunroof, and a driver assistance package with features like adaptive cruise control and lane-keeping assist. Interior color options were varied, allowing buyers to personalize their vehicle. The dashboard layout was typical of Mercedes-Benz at the time, with a focus on elegance and functionality.
Chassis & Braking
The CLS 550 features a sophisticated chassis designed to deliver a comfortable and controlled ride. The front suspension utilizes an independent multi-link setup with a transverse stabilizer and air suspension. The rear suspension also employs an independent multi-link design with air suspension and a transverse stabilizer. The air suspension allows the ride height to be adjusted, providing a balance between comfort and handling. The braking system consists of ventilated discs on all four wheels, with larger discs up front to provide increased stopping power. Anti-lock brakes (ABS) are standard, along with electronic stability control.
Market Reception & Comparison
The CLS 550 V8 was generally well-received by automotive critics, who praised its powerful engine, refined ride, and luxurious interior. However, some reviewers noted that the car’s styling was polarizing and that the rear seat space was somewhat limited. Compared to the CLS 350, the 550 offered a significant performance upgrade, but at a higher price point. Fuel economy was comparable to other V8-powered luxury coupes. Reliability has been generally good, although some owners have reported issues with the air suspension system.
Legacy
The Mercedes-Benz CLS 550 V8 (C218) remains a desirable vehicle in the used car market today. Its combination of luxury, performance, and distinctive styling continues to appeal to buyers. The M278 engine has proven to be relatively reliable, although regular maintenance is essential. The 7G-TRONIC PLUS transmission is also known for its durability. The CLS 550 represents a significant chapter in Mercedes-Benz’s history, solidifying the brand’s position as a leader in the luxury coupe segment and influencing the design of future models.
