The Mercedes-Benz CLS 550 V8 (4MATIC) represents the high-performance variant of the C218 CLS-Class coupe, produced between 2011 and 2014. Positioned as the flagship model within the C218 range, it offered a blend of luxury, performance, and technology. The CLS, initially launched in 2004, pioneered the four-door coupe segment, and the C218 generation continued this trend with its sleek, sloping roofline and sophisticated interior. The 550 model, equipped with a naturally aspirated 5.5-liter V8 engine and a seven-speed automatic transmission, catered to buyers seeking a more powerful and refined driving experience than the CLS 350 or the later diesel variants.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | CLS |
| Generation | CLS coupe (C218) |
| Type (Engine) | CLS 550 V8 (402 Hp) 4MATIC 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) | 13.1-14.7 l/100 km (18-16 US mpg, 21.6-19.2 UK mpg, 7.6-6.8 km/l) |
| Fuel consumption (extra urban) | 9.4 l/100 km (25 US mpg, 30.1 UK mpg, 10.6 km/l) |
| Fuel consumption (combined) | 12.4 l/100 km (19 US mpg, 22.8 UK mpg, 8.1 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 60 mph | 5.2 sec |
| Maximum speed | 210 km/h (130.49 mph) – Electronically limited |
| Weight-to-power ratio | 4.8 kg/Hp, 207.6 Hp/tonne |
| Weight-to-torque ratio | 3.2 kg/Nm, 309.9 Nm/tonne |
| Power | 402 Hp @ 5000-5750 rpm |
| Power per litre | 86.2 Hp/l |
| Torque | 600 Nm @ 1600-4750 rpm (442.54 lb.-ft. @ 1600-4750 rpm) |
| 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 | 1936 kg (4268.15 lbs.) |
| Max. weight | 2421 kg (5337.39 lbs.) |
| Max load | 485 kg (1069.24 lbs.) |
| Trunk (boot) space – minimum | 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 (Back) 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 | All wheel drive (4×4) |
| 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 |
Powertrain & Engine Architecture
The heart of the CLS 550 is the M278.922 5.5-liter V8 engine. This engine utilizes direct fuel injection and twin turbochargers to produce 402 horsepower and 600 Nm (442.54 lb-ft) of torque. The engine features a DOHC (Double Overhead Camshaft) valvetrain and a compression ratio of 10.5:1. The M278 engine family was notable for its use of aluminum construction, reducing weight, and incorporating features like cylinder deactivation to improve fuel economy. The engine is longitudinally mounted at the front of the vehicle. Power is transmitted to all four wheels via Mercedes-Benz’s 7G-TRONIC PLUS seven-speed automatic transmission. This transmission was known for its smooth shifting and responsive performance, offering both automatic and manual shift modes.
Driving Characteristics
The CLS 550 4MATIC delivers a refined and powerful driving experience. The twin-turbo V8 provides ample acceleration, with a 0-60 mph time of 5.2 seconds. The 7G-TRONIC PLUS transmission contributes to smooth gear changes, enhancing both comfort and performance. Compared to the CLS 350, the 550 offers significantly more power and torque, resulting in a more engaging driving experience. While not as overtly sporty as some competitors, the CLS 550 strikes a balance between luxury and performance. The 4MATIC all-wheel-drive system provides excellent traction in various weather conditions. The air suspension, standard on this model, further enhances ride comfort.
Equipment & Trim Levels
The CLS 550 typically came standard with a high level of equipment, including leather upholstery, wood trim, a premium sound system, and a comprehensive suite of safety features. Standard features included dual-zone automatic climate control, power-adjustable front seats with memory function, and a multi-function steering wheel. Optional extras included a panoramic sunroof, upgraded leather options, a rear-seat entertainment system, and advanced driver-assistance systems such as lane-keeping assist and adaptive cruise control. The interior design emphasized luxury and sophistication, with a focus on high-quality materials and craftsmanship.
Chassis & Braking
The C218 CLS 550 features an independent multi-link suspension at both the front and rear, enhanced by an air suspension system. This setup provides a comfortable ride while maintaining good handling characteristics. The 4MATIC all-wheel-drive system distributes power between the front and rear axles for optimal traction. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. The front brakes measure 360x36mm, while the rear brakes are 320x24mm. Anti-lock braking system (ABS) is standard, along with electronic stability control.
Market Reception & Comparison
The CLS 550 was generally well-received by automotive critics, who praised its powerful engine, luxurious interior, and refined driving experience. However, some reviewers noted that the fuel economy was relatively low for a vehicle in its class. Compared to other performance coupes, such as the BMW 6 Series and Audi A7, the CLS 550 offered a unique blend of style, luxury, and performance. The CLS 550’s fuel economy figures of around 19 US mpg combined were typical for a V8-powered vehicle of its size and performance. Reliability was generally good, although some owners reported minor issues with electronic components.
Legacy
The Mercedes-Benz CLS 550 (C218) remains a desirable vehicle in the used car market. The M278 engine, while complex, is generally considered reliable when properly maintained. Regular servicing, including oil changes and spark plug replacements, is crucial for ensuring long-term reliability. The 7G-TRONIC PLUS transmission is also known for its durability. The CLS 550’s combination of luxury, performance, and distinctive styling continues to appeal to buyers seeking a sophisticated and capable grand tourer. Its pioneering role in establishing the four-door coupe segment has cemented its place in automotive history.
