The Mercedes-Benz CLS 450 4MATIC, produced from 2018 to 2021 as part of the C257 generation CLS, represents a significant evolution in the four-door coupe segment. Positioned as a mid-to-upper range offering within the CLS lineup, it blended luxury, performance, and cutting-edge technology, particularly with the introduction of EQ Boost mild-hybrid technology. This variant aimed to deliver a refined driving experience with enhanced fuel efficiency compared to its more powerful siblings, while still providing the dynamic capabilities expected of a Mercedes-Benz. The C257 CLS, overall, sought to redefine the traditional coupe aesthetic with a focus on elegant design and sophisticated engineering.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | CLS |
| Generation | CLS coupe (C257) |
| Type | CLS 450 (367 Hp) EQ Boost 4MATIC 9G-TRONIC |
| Start of production | 2018 |
| End of production | 2021 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Coupe |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption at Low speed (WLTP) | 8 l/100 km (29.4 US mpg, 35.3 UK mpg, 12.5 km/l) |
| Fuel consumption at very high speed (WLTP) | 9.1 l/100 km (25.8 US mpg, 31 UK mpg, 11 km/l) |
| CO2 emissions (WLTP) | 183-207 g/km |
| Fuel consumption (economy) – urban | 9.8-10.1 l/100 km (24 – 23.3 US mpg, 28.8 – 28 UK mpg, 10.2 – 9.9 km/l) |
| Fuel consumption (economy) – extra urban | 6.1-6.4 l/100 km (38.6 – 36.8 US mpg, 46.3 – 44.1 UK mpg, 16.4 – 15.6 km/l) |
| Fuel consumption (economy) – combined | 7.5-7.8 l/100 km (31.4 – 30.2 US mpg, 37.7 – 36.2 UK mpg, 13.3 – 12.8 km/l) |
| CO2 emissions | 178-184 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4.8 sec |
| Acceleration 0 – 62 mph | 4.8 sec |
| Acceleration 0 – 60 mph | 4.6 sec |
| Maximum speed | 250 km/h (155.34 mph), Electronically limited |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 5.1 kg/Hp, 196.8 Hp/tonne |
| Weight-to-torque ratio | 3.7 kg/Nm, 268.1 Nm/tonne |
| Gross battery capacity | 0.9 kWh |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 22 Hp |
| Electric motor Torque | 250 Nm (184.39 lb.-ft.) |
| Electric motor location | Between the combustion engine and the transmission |
| Power | 367 Hp |
| Power per litre | 122.4 Hp/l |
| Torque | 500 Nm (368.78 lb.-ft.) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 256.930 |
| Engine displacement | 2999 cm3 (183.01 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 83 mm (3.27 in.) |
| Piston Stroke | 92.4 mm (3.64 in.) |
| Compression ratio | 10.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-scroll turbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 8.5 l (8.98 US qt | 7.48 UK qt) |
| Coolant | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 1865 kg (4111.62 lbs.) |
| Max. weight | 2585 kg (5698.95 lbs.) |
| Max load | 720 kg (1587.33 lbs.) |
| Fuel tank capacity | 66 l (17.44 US gal | 14.52 UK gal) |
| Permitted trailer load with brakes (12%) | 1900 kg (4188.78 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Length | 4988 mm (196.38 in.) |
| Width | 1890 mm (74.41 in.) |
| Height | 1435 mm (56.5 in.) |
| Wheelbase | 2939 mm (115.71 in.) |
| Front track | 1618 mm (63.7 in.) |
| Front overhang | 888 mm (34.96 in.) |
| Rear overhang | 1161 mm (45.71 in.) |
| Ride height (ground clearance) | 93 mm (3.66 in.) |
| Drag coefficient (Cd) | 0.26 |
| Approach angle | 13.4° |
| Departure angle | 12.2° |
| Drivetrain Architecture | ICE and electric motor drive all four wheels, mixed mode operation |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
INTRODUCTION
The Mercedes-Benz CLS 450 4MATIC (C257) debuted in 2018, marking the third generation of the CLS-Class. This generation moved the CLS further into the realm of a four-door coupe, emphasizing style and luxury while incorporating advanced technology. The CLS 450, with its 3.0-liter inline-six engine and 4MATIC all-wheel drive, served as a key model within the range, offering a balance between performance and efficiency. It was positioned above the base CLS 350d and below the more performance-oriented AMG CLS 53, catering to buyers seeking a sophisticated and comfortable grand tourer. The introduction of the EQ Boost system, a 48-volt mild-hybrid system, was a defining feature of this generation, enhancing both fuel economy and responsiveness.
Powertrain & Engine Architecture
At the heart of the CLS 450 lies the M 256.930 3.0-liter inline-six cylinder engine. This engine is a technological marvel, featuring direct injection, a twin-scroll turbocharger, and an intercooler. The engine code signifies its position within Mercedes-Benz’s modular engine family. The M 256 engine is notable for its “cylinder shutoff” system (also known as CAMTRONIC), which can deactivate cylinders under light load conditions to improve fuel efficiency. The EQ Boost system adds a 22 horsepower electric motor integrated into the transmission, providing an additional boost during acceleration and enabling a smoother start/stop function. The electric motor is powered by a 48V lithium-ion battery. The transmission is a 9G-TRONIC nine-speed automatic, known for its smooth shifts and wide gear ratios. This transmission is specifically tuned to work in conjunction with the EQ Boost system, optimizing power delivery and efficiency.
Driving Characteristics
The CLS 450 4MATIC delivers a refined and comfortable driving experience. The 367 horsepower and 500 Nm (368.78 lb-ft) of torque provide ample power for both highway cruising and spirited driving. The EQ Boost system contributes to a responsive feel, filling in gaps in torque delivery and providing a subtle but noticeable performance enhancement. The 9G-TRONIC transmission shifts smoothly and efficiently, and the all-wheel-drive system provides excellent traction in various conditions. Compared to the CLS 350d, the 450 offers significantly more power and a more engaging driving experience. While not as aggressively tuned as the AMG CLS 53, the 450 strikes a good balance between performance and comfort. The gear ratios are optimized for both fuel efficiency and acceleration, with a focus on providing a relaxed driving experience at highway speeds.
Equipment & Trim Levels
The CLS 450 4MATIC came standard with a comprehensive list of features, reflecting its positioning as a luxury vehicle. Standard equipment included leather upholstery, heated front seats, a premium sound system, a large infotainment display with Mercedes-Benz’s MBUX system, and a suite of advanced driver-assistance systems such as adaptive cruise control, lane-keeping assist, and automatic emergency braking. Optional extras included ventilated front seats, a panoramic sunroof, a head-up display, and upgraded interior trim options. The interior design emphasized a modern and minimalist aesthetic, with high-quality materials and meticulous attention to detail. Dashboard configuration featured dual 12.3-inch displays, one for the instrument cluster and one for the infotainment system.
Chassis & Braking
The CLS 450 4MATIC features a sophisticated chassis designed to provide a comfortable and controlled ride. The suspension utilizes a multi-link setup at both the front and rear, optimized for both handling and ride comfort. The 4MATIC all-wheel-drive system provides excellent traction and stability. Braking duties are handled by ventilated discs at all four corners, providing ample stopping power. The braking system is equipped with ABS (Anti-lock Braking System), electronic brake-force distribution, and brake assist. The CLS 450 typically featured a stabilizer bar to reduce body roll during cornering, enhancing handling precision.
Market Reception & Comparison
The CLS 450 4MATIC was generally well-received by automotive critics. It was praised for its stylish design, luxurious interior, and refined driving experience. The EQ Boost system was also noted as a positive feature, contributing to improved fuel efficiency and responsiveness. Compared to the CLS 350d, the 450 offered a more engaging driving experience, while remaining competitive in terms of fuel economy. Compared to the AMG CLS 53, the 450 prioritized comfort and refinement over outright performance. Some critics noted that the infotainment system could be complex to navigate, but overall, the CLS 450 was considered a strong contender in the luxury four-door coupe segment.
Legacy
The Mercedes-Benz CLS 450 4MATIC (C257) represents a significant step forward in the evolution of the CLS-Class. The introduction of the EQ Boost system demonstrated Mercedes-Benz’s commitment to hybrid technology and fuel efficiency. The M 256 inline-six engine has proven to be a reliable and durable powerplant. On the used car market, the C257 CLS 450 4MATIC holds its value well, attracting buyers who appreciate its combination of style, luxury, and technology. While some maintenance costs associated with Mercedes-Benz vehicles can be higher than average, the CLS 450’s robust engineering and build quality contribute to its long-term reliability. The C257 generation CLS, and the 450 variant in particular, cemented the model’s position as a desirable and sophisticated grand tourer.
