Maintaining the 2018 Audi S6 requires precise attention to its lubrication needs, particularly given its aggressive 4.0-liter twin-turbo V8 engine. The high-output performance of this vehicle places significant stress on engine components, making the use of a high-quality synthetic motor oil essential for long-term reliability and peak power delivery. Beyond the engine, the S6’s advanced 7-speed automatic transmission and Quattro all-wheel-drive system demand specific fluid formulations to ensure smooth shifting and efficient power distribution. Using the correct AMSOIL 5W-40 MS Motor Oil, AMSOIL DCT Fluid, and AMSOIL Gear Lube helps manage extreme temperatures, reduces friction, and protects against the wear caused by turbocharging and high-RPM driving.
Recommended AMSOIL Products
- AMSOIL 5W-40 MS 100% Synthetic European Motor Oil – A premium European formula designed for the unique demands of gasoline, diesel, and hybrid European vehicles, featuring a precise blend of synthetic base oils and premium additives for superior engine protection.
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – Engineered specifically for European gasoline and diesel vehicles, this oil offers exceptional thermal stability and engine cleanliness for the S6’s high-performance twin-turbo engine.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An excellent low-temperature option for the S6, providing rapid oil flow at startup while maintaining robust high-temperature protection under heavy loads and extreme heat.
- AMSOIL 100% Synthetic DCT Fluid – Designed to prevent shudder and provide outstanding wear protection for the S6’s 7-speed automatic transmission, performing reliably in both extreme cold and intense heat.
- AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube – Specifically formulated to protect the S6’s front and rear differentials from rust, corrosion, and high-load gear stress while improving cold-weather shifting and extending seal life.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix ethylene glycol formula that provides protection up to 150,000 miles or 5 years, safeguarding cooling system metals and preventing corrosion in the S6’s engine cooling system.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated, eco-friendly antifreeze option that requires mixing with distilled water, offering extended service life and superior corrosion protection for passenger car cooling systems.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent responsiveness for ABS and traction-control systems with a stable viscosity across a wide temperature range to ensure reliable braking performance.
The engine of the 2018 Audi S6 is a formidable machine, featuring a 4.0-liter twin-turbocharged V8. This powertrain is capable of generating significant horsepower, but the intense heat and pressure generated during operation require a lubricant that can withstand extreme conditions without breaking down. The recommended oil change capacity for this engine is 9.2 quarts when including the filter replacement. It is critical to use an oil that meets the specific Audi and Volkswagen quality standards applicable to this engine code (CTGE 5) to ensure warranty compliance and optimal performance. When the oil level is checked after the refill, it is important to verify the level and torque the oil drain plug to 15 foot-pounds to prevent leaks and ensure the new seal is properly compressed.
Fluid maintenance extends well beyond the engine block. The S6 is equipped with a sophisticated 7-speed automatic transmission that relies on the specific AMSOIL 100% Synthetic DCT Fluid to maintain its smooth operation. The total fill capacity for this transmission is approximately 7.9 quarts, with an initial fill capacity of 5.8 quarts, though this can vary slightly between 5.5 and 6.0 liters depending on the specific unit. Using the correct fluid is vital to prevent shudder and ensure the transmission delivers power to all four wheels efficiently. Similarly, the differential lubrication is a key component of the Quattro system. Both the front and rear differentials require 75W-90 Long Life 100% Synthetic Gear Lube. The front differential requires 2.1 pints, while the rear requires 1.9 pints. These synthetic gear lubes offer high-load protection and improved seal life, which is crucial for a performance sedan that may see spirited driving.
Cooling system integrity is equally important for a turbocharged vehicle. The S6 cooling system holds 15.9 quarts of coolant. Owners have two primary choices for this service: the AMSOIL Passenger Car & Light Truck Antifreeze & Coolant, which is a ready-to-use 50/50 pre-mix, or the AMSOIL Propylene Glycol Antifreeze and Engine Coolant, which is a concentrated formula requiring mixing with distilled water. Both options offer phosphate-, nitrate-, nitrite-, silicate-, borate-, and amine-free formulations that protect all cooling system metals, gaskets, and hoses. The Propylene Glycol option is particularly noted for its ecological benefits and ability to withstand extreme conditions, protecting against metallic corrosion and erosion. Additionally, the brake fluid in the S6 is a DOT 4 hydraulic fluid. Replacing this with a synthetic DOT 3 and DOT 4 blend ensures consistent pedal feel and prevents moisture absorption, which can lead to corrosion in the brake lines and calipers.
Vehicle Background and Performance Profile
The 2018 Audi S6 is a high-performance luxury sedan that stands as a potent alternative to the sportier S8 and the standard A6 lineup. Developed under the Volkswagen Group’s platform engineering, this model represents the “S” performance tier, offering a compelling blend of daily drivability and track-capable speed. The vehicle is powered by the 4.0-liter twin-turbo V8 engine, internally designated as the CTGE 5, which produces significant horsepower and torque figures that rival many supercars. This powertrain is paired with an advanced 7-speed S tronic automatic transmission and Audi’s renowned Quattro all-wheel-drive system, ensuring that the substantial power is delivered to the road with precision and stability.
Owners of the S6 often appreciate its dual nature: it serves as a sophisticated, comfortable cruiser for daily commutes while providing an adrenaline-fueled driving experience when the road opens up. The interior is typically equipped with high-end materials and technology, positioning the car as a competitive choice against rivals like the Mercedes-Benz E63 AMG and the BMW 5 Series M5. The design language of the S6 is sleek and aerodynamic, with distinct styling cues that set it apart from the standard A6, including unique front grilles, wider fenders, and sport-tuned suspension components. The car’s reputation is built on its ability to deliver luxury and performance simultaneously, making it a favorite among enthusiasts who require a versatile vehicle for various driving conditions.
Despite its robust engineering, the 2018 S6 faces common issues associated with high-performance turbocharged engines and complex electronic systems. One frequent concern is oil consumption or leakage, which can be exacerbated by the high operating temperatures of the twin-turbo setup. High-quality synthetic oils provide better thermal stability and seal conditioning, helping to mitigate these leaks and reduce consumption. Another common area of concern is the cooling system, where mineral deposits or corrosion can accumulate over time, leading to overheating issues. Using a high-performance coolant with superior anti-corrosion properties helps keep the cooling system clean and efficient, preventing costly damage to the radiator and engine block. Additionally, the S6’s dual-mass flywheel and transmission can sometimes experience shudder or delayed shifts due to fluid degradation; switching to a dedicated synthetic DCT Fluid can significantly improve shift quality and extend the lifespan of transmission components. Finally, carbon buildup on the intake valves is a known issue in direct injection engines, which can affect performance and fuel economy; regular use of performance fuel additives like AMSOIL P.i. Performance Improver helps prevent this buildup, keeping the engine running at its optimal efficiency.
In summary, the 2018 Audi S6 is a remarkable vehicle that demands the best in lubrication technology to maintain its performance potential. By selecting the appropriate AMSOIL Motor Oil, Gear Lube, DCT Fluid, and Antifreeze & Coolant for every fluid reservoir, owners can ensure that their S6 continues to deliver the expected level of luxury, power, and reliability for years to come. The comprehensive approach to fluid maintenance, covering the engine, transmission, differentials, cooling system, and brakes, forms the foundation of a well-maintained high-performance vehicle.