The 2018 Mercedes-Benz S65 AMG is a masterpiece of German engineering, housing a formidable 6.0L V12 biturbo engine that delivers unparalleled performance. However, this level of power places significant demands on the vehicle’s lubrication systems. Proper maintenance is not merely about meeting mileage schedules; it is about ensuring that the intricate components of this high-performance luxury sedan receive the protection they need against extreme heat, high RPM stress, and extended driving intervals. Using the correct synthetic oils, coolant, and transmission fluids ensures the longevity of the engine, transmission, and cooling systems, keeping this grand tourer performing at its peak.
Recommended AMSOIL Products
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – Engineered specifically for the unique demands of gasoline, diesel, and hybrid European vehicles, offering precise protection for high-performance engines.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – A premium European formula featuring a precise blend of synthetic base oils and additives designed to handle extreme operating conditions.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – An OAT formulation that protects cooling system metals, gaskets, and hoses while providing up to 150,000 miles or 5 years of protection.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands the rigors of heavy towing, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Provides reliable protection against wear for automatic transmissions requiring OE-approved specifications.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range.
When maintaining a vehicle of this caliber, the engine oil serves as the lifeblood of the machine. The 2018 S65 AMG operates with a 6.0-liter V12 engine code 279.98 H Turbo, a powerplant known for its immense torque and high-temperature operation. The oil capacity for this engine is approximately 11.1 quarts, including the filter. It is crucial to check the oil level after a refill to ensure proper lubrication of the vast internal components. The torque specification for the oil drain plug is 22 ft/lbs, and owners should always replace the drain plug seal during service to prevent leaks. For this vehicle, AMSOIL offers two viscosity options that cover all temperatures: 0W-40 and 5W-40. Both formulations are designed to flow quickly at startup to reduce wear and maintain film strength under the intense thermal stress of a twin-turbocharged engine.
Beyond the crankcase, the cooling system requires attention to prevent overheating, which can be detrimental to the aluminum block and head gaskets of the V12. The cooling system capacity varies depending on whether the engine is a Heavy Truck Coolant Configuration (HTCC), which requires 11.6 quarts, or a Light Truck Coolant Configuration (LTCC), which requires 2 quarts. The recommended AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is an ethylene glycol 50/50 pre-mix that is phosphate, nitrate, nitrite, silicate, borate, and amine-free, ensuring compatibility with the various metals and seals used in Mercedes-Benz cooling systems. For those who prefer a concentrated solution that offers extended service life and flexibility in mixing, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant provides protection up to 150,000 miles in passenger cars.
The transmission in the 2018 S65 AMG is a critical component that translates the engine’s raw power to the road. For models with the 722.9 transmission, specifically those with the A89 code for reduced friction, the total fill capacity is 9.5 quarts for the 7-speed system. Whether the vehicle has the A89 reduced-friction code or operates without it, the transmission demands a fluid that can handle the heat generated by high-speed shifting and the torque from the V12 engine. AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is designed to withstand the rigors of heavy towing and elevated temperatures while maintaining fluidity in sub-zero conditions. Alternatively, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers OE-approved protection for those seeking a cost-effective yet high-performance solution.
Brake fluid is another fluid that often gets overlooked until it is too late. For the S65 AMG, the recommended fluid is a DOT 4 plus, specifically MB Sheet 331.0 approved fluid (such as part numbers 0009895605090109 or 0009895605110111). Using a non-synthetic fluid can lead to moisture absorption, which lowers the boiling point and can cause brake fade under extreme braking conditions. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid offers a stable viscosity and excellent responsiveness for the vehicle’s ABS and traction control systems, ensuring safe stopping power regardless of the weather or driving intensity.
While the primary focus is on engine and transmission fluids, the overall health of the vehicle benefits from a comprehensive approach to lubrication. Owners can utilize AMSOIL P.i. Performance Improver Gasoline Additive to restore up to 14% horsepower and clean GDI fuel injectors, which is particularly beneficial for maintaining fuel efficiency and preventing carbon buildup in the combustion chambers. Additionally, for seasonal storage or long periods of inactivity, AMSOIL Engine Fogging Oil can be used to protect internal engine components from rust and corrosion.
Vehicle Background
The 2018 Mercedes-Benz S65 AMG represents the pinnacle of the S-Class lineage during this era, combining the ultimate luxury of the S-Class platform with the aggressive performance of the AMG sub-brand. Built on the W222 chassis, the S65 AMG is distinguished by its handcrafted 6.0-liter V12 twin-turbo engine, a massive powerplant that produces roughly 621 horsepower and 738 lb-ft of torque. This makes it one of the most powerful non-electric production sedans available in its class, offering acceleration that rivals many supercars while maintaining the serene ride quality expected of a flagship Mercedes-Benz sedan.
The S65 AMG was a flagship model for Mercedes-AMG, positioned at the top of the S-Class hierarchy before the introduction of the S63 and subsequent AMG 8-cylinder and V8 models took center stage in some markets. It was designed for drivers who wanted to command the road with absolute authority, featuring a sophisticated rear-wheel-drive system with optional all-wheel drive in certain configurations. The interior was a sanctuary of luxury, featuring Nappa leather, exotic wood trim, and the latest MBUX and COMAND infotainment systems, making it a favorite among corporate executives and discerning individuals who demanded both comfort and performance.
However, owning a high-performance V12 is not without its challenges. The complexity of the engine and the high stress it endures can lead to specific issues that require attentive maintenance. One common problem for the S65 AMG is the wear of the V12 engine’s valve train components due to the high pressures and temperatures of the twin-turbo setup. Using a high-zinc or high-shear-stable synthetic motor oil can help mitigate wear on the camshafts and lifters, extending the life of these critical components.
Another frequent issue is related to the cooling system, particularly the electric water pumps and thermostat housings. Over time, the constant thermal cycling can lead to cracks or leaks. While replacing these parts is necessary, ensuring the cooling system uses a high-quality, corrosion-resistant antifreeze like the AMSOIL OAT formulations can help protect the aluminum components from pitting and erosion, preventing premature failures. The S65 AMG also utilizes a complex multi-link rear suspension that requires regular inspection of bushings and seals; using synthetic multi-purpose grease on chassis components can help maintain flexibility and reduce noise over time.
Furthermore, the electronic systems in the S65 AMG, including the complex air suspension and drive dynamics, are sensitive to power supply fluctuations and ground issues, which can sometimes be exacerbated by older batteries or poor electrical connections. Regular maintenance of the battery terminals with a silicone spray or metal protector can prevent corrosion and ensure reliable electrical performance. By addressing these specific areas with the right lubricants and additives, owners can mitigate some of the common failure points associated with this powerful and sophisticated vehicle, ensuring that the S65 AMG remains a reliable and exhilarating experience for years to come.
In conclusion, the 2018 Mercedes-Benz S65 AMG is a vehicle that demands the best. Its engineering excellence is matched by the need for superior lubrication. By selecting the correct AMSOIL synthetic oils and fluids, owners can provide the necessary protection against the unique challenges posed by the V12 biturbo engine and the vehicle’s advanced systems. Whether it is through the use of 0W-40 or 5W-40 FS motor oil, a premium antifreeze, or a high-performance transmission fluid, the right choice in lubricants ensures that the S65 AMG continues to deliver the performance and luxury it was designed for.