The 2018 Mercedes-Benz CLS550 is a sophisticated luxury vehicle equipped with a twin-turbocharged 4.7-liter V8 engine. This powerful powertrain demands lubricants that can withstand high operating temperatures, rapid acceleration, and the extreme stresses associated with turbocharged performance. Using generic oils can lead to premature wear, sludge buildup, and reduced engine longevity, especially given the vehicle’s tight tolerances and high horsepower output.
Proper lubrication is not just about meeting the manufacturer’s minimum requirements; it is about maximizing the vehicle’s potential for extended service intervals and superior protection in severe driving conditions. Whether you are navigating city traffic with frequent stop-and-go patterns or enjoying spirited driving on the open road, the right AMSOIL 5W-40 FS 100% Synthetic European Motor Oil or AMSOIL 0W-40 FS 100% Synthetic European Motor Oil provide a protective barrier that minimizes friction, reduces oil consumption, and keeps the engine cleaner for longer.
Recommended AMSOIL Products
For the 2018 CLS550, the engine requires a high-performance synthetic oil specifically designed for European turbocharged engines. The recommended oil change capacity is 8.5 quarts when the filter is replaced. Below are the essential products to keep your vehicle running at its peak.
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – This premium oil is formulated specifically for the high-temperature demands of European vehicles, offering exceptional wear protection and engine cleanliness for the 4.7L V8.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An excellent alternative for extreme cold weather operation, this fluid provides superior cold-start protection while maintaining stability in high heat.
- WIX Oil Filter – Designed to complement the synthetic oil with premium filtration media that traps contaminants more effectively than standard OEM filters, ensuring clean oil circulation throughout the engine.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A phosphate, nitrite, and silicate-free formula that protects the cooling system metals and hoses, preventing corrosion and maintaining optimal engine temperature.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – For those who prefer a concentrated option, this antifreeze offers outstanding protection up to 150,000 miles and is compatible with all cooling system metals.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – This synthetic fluid provides stable viscosity over a wide temperature range, ensuring responsive ABS and traction control performance for the CLS550’s braking system.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Helps seals remain soft to prevent leaks and resists heat for long fluid life, ensuring quiet and smooth steering operation.
Why Proper Lubrication Matters for the CLS550
The 2018 Mercedes-Benz CLS550 is a complex machine where every component relies on precise lubrication to function correctly. The 4.7-liter V8 engine code 278.92 G Turbo is a masterpiece of engineering, featuring dual turbochargers that generate significant heat. Without a high-quality synthetic lubricant capable of withstanding these thermal loads, the oil can break down, leading to increased friction and accelerated wear on critical components like the camshafts, bearings, and turbocharger shafts.
AMSOIL synthetic motor oils are engineered to resist thermal breakdown and oxidation far better than conventional oils. This means the oil maintains its viscosity and protective qualities for extended periods, even when the engine is subjected to high RPMs or extreme ambient temperatures. Furthermore, the CLS550’s engine management systems and exhaust treatment technologies rely on low-ash and compatible oil formulations to prevent clogging and ensure optimal performance. The recommended AMSOIL FS European formulas are specifically blended to meet these rigorous European standards, often exceeding them.
Beyond the engine, the vehicle’s other fluid systems play a crucial role in its overall health. The braking system requires a fluid with a high boiling point to prevent brake fade under hard stopping conditions. AMSOIL’s synthetic brake fluid exceeds DOT 4 standards, ensuring consistent pedal feel and ABS responsiveness. Similarly, the power steering system benefits from a fluid that resists foaming and protects seals, preventing leaks that can be costly and messy to repair. Maintaining a complete fluid profile ensures that the vehicle operates with the precision it was designed for.
While the source data does not list specific capacity figures for the transmission or differential, it is important to note that regular maintenance of these systems is vital. The absence of specific recommendations for transmission fluid changes in the source material does not diminish the importance of using the correct fluid if a change is required. For the cooling system, the CLS550 utilizes a significant amount of AMSOIL Passenger Car Antifreeze or AMSOIL Propylene Glycol Antifreeze, with capacities noted as 2.2 quarts for certain components and up to 11.4 quarts for full system capacity depending on the specific configuration. Using a coolant that protects against corrosion and freezing is essential for the longevity of the radiator and heater core.
About the Vehicle
The 2018 Mercedes-Benz CLS550 represents a distinct segment of the automotive market, blending the sleek, coupe-like styling of a four-door with the practicality of a sedan. As part of the CLS-Class line, which was introduced to Mercedes-Benz as the “four-door coupe” concept, this model appeals to drivers who desire the aggressive aesthetics and sporty posture of a sports car without sacrificing the utility of a luxury sedan. The CLS platform is based on the Mercedes-Benz M-Class (now GLE) chassis but features a lower, longer, and more sloping roofline that defines its unique silhouette.
Under the hood, the 2018 CLS550 is powered by the robust 4.7-liter M278 DE47LA V8 engine. This twin-turbocharged unit is renowned for its impressive power delivery and responsiveness. In the CLS550 trim, this engine typically produces around 449 to 455 horsepower and 516 lb-ft of torque. This substantial power output is managed by the 7G-TRONIC PLUS 7-speed automatic transmission, which provides smooth, rapid gear changes via the SPEEDSHIFT DCT mode. The combination of the powerful engine and the agile chassis allows the CLS550 to accelerate from zero to sixty miles per hour in under four seconds, offering performance that rivals dedicated sports cars.
Driving the CLS550 is an engaging experience. The vehicle’s suspension is tuned to balance comfort with sporty handling, making it suitable for both daily commuting and spirited weekend drives. The interior reflects the high standards of the Mercedes-Benz brand, featuring premium leather, advanced infotainment systems, and ergonomic driver aids. The design language emphasizes a driver-focused cockpit with a wide dashboard and intuitive controls.
Owners of the CLS550 often cite the vehicle’s unique design and performance capabilities as primary reasons for their choice. However, like any high-performance European vehicle, the CLS550 has specific maintenance needs that can be challenging. The high-output turbocharged engine can be prone to carbon buildup on the intake valves, particularly in GDI (Gasoline Direct Injection) applications, which is why using fuel additives like AMSOIL P.i. Performance Improver can be a proactive maintenance step to restore injectors and improve efficiency. Additionally, the turbochargers operate at extremely high temperatures, placing significant stress on the engine oil. Over time, standard oils can break down, leading to potential issues with oil consumption or sludge formation. Using a high-quality synthetic oil like AMSOIL FS can help mitigate these issues by providing superior thermal stability and engine cleanliness.
Another common concern for owners of this era of Mercedes-Benz is the integrity of the cooling system and seals. The complex cooling circuits and the use of various plastics and rubber seals can be susceptible to degradation over time, leading to leaks. Regular fluid changes with a high-quality, non-corrosive antifreeze like AMSOIL OAT formulation can help extend the life of the cooling system components and seals. Furthermore, the power steering system, which relies on hydraulic assistance, may develop leaks as seals age. Switching to a synthetic AMSOIL power steering fluid that is specifically designed to condition seals and resist heat degradation can help prevent these leaks and maintain smooth steering operation.
The CLS550 is a vehicle that demands respect and proper care. Its performance characteristics are not just about speed but about the refinement of the driving experience. By adhering to a strict maintenance schedule with high-performance lubricants, owners can ensure that their CLS550 remains a reliable and exhilarating machine for years to come. The investment in premium fluids pays off in reduced wear, fewer unexpected repairs, and a vehicle that continues to perform like new long after it has left the dealership.