The 2018 Audi S8, equipped with its formidable 4.0L twin-turbo V8 engine, represents the pinnacle of Audi’s performance engineering. This vehicle demands lubrication solutions that can withstand the extreme thermal and mechanical stresses generated by high-output turbocharged engines, aggressive driving, and the complex requirements of a luxury sedan platform. Proper fluid maintenance is not merely a routine task for this car; it is essential for preserving the integrity of the engine’s precision components, maintaining the responsiveness of the 8-speed automatic transmission, and ensuring the longevity of the entire powertrain. Using the correct AMSOIL synthetic lubricants ensures that the S8 operates at peak efficiency, providing superior protection against wear, sludge, and corrosion while extending service intervals compared to conventional alternatives.
Recommended AMSOIL Products
- AMSOIL 5W-40 MS 100% Synthetic European Motor Oil – A premium synthetic formula specifically designed for the unique demands of gasoline, diesel, and hybrid European vehicles, offering precise protection for the S8’s turbocharged engine.
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – An outstanding option that features a European formula with a precise blend of synthetic base oils and premium additives to meet the rigorous standards of this high-performance Audi.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – Ideal for varying climates, this synthetic oil provides exceptional flow in extreme cold while maintaining robust protection at high operating temperatures common in this engine.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid (OAT) formulation that provides protection up to 150,000 miles or 5 years, safeguarding the cooling system metals, gaskets, and hoses against corrosion.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Designed to withstand the rigors of heavy towing, elevated temperatures, and challenging terrain, this fluid remains fluid in sub-zero temperatures to ensure smooth shifting.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A fuel-efficient synthetic option that protects against wear and provides reliable performance for the 8-speed automatic transmission found in this vehicle.
- AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube – Specifically engineered for high-load gear and bearing protection, this synthetic lubricant improves seal life and shifting while resisting rust and corrosion in the differential.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides excellent ABS and traction-control responsiveness with stable viscosity over a wide temperature range for superior stopping power.
- AMSOIL P.i. Performance Improver Gasoline Additive – Helps restore fuel injectors to 100% flow rate and can restore up to 14% horsepower, controlling pre-ignition knock and reducing the need for higher-octane fuel.
When performing a fluid change on the 2018 Audi S8, precision is key. The engine oil capacity is 9.2 quarts when a filter replacement is included. It is critical to ensure the oil meets the specific Audi and Volkswagen oil quality standards, with 5W-40 viscosity being the primary recommendation for all temperatures. The oil drain plug requires a torque of 15 ft/lbs, and the drain plug seal should always be replaced during the service. After refilling, the oil level must be checked to ensure optimal operation. For cooling, the system requires 15.9 quarts of fluid. If a concentrated AMSOIL Propylene Glycol Antifreeze and Engine Coolant is chosen, it must be mixed with distilled or high-quality water before use.
The transmission fluid specifications are equally critical for the 8-speed automatic unit. A total fill requires 9.1 quarts, while an initial fill capacity sits between 3.8 and 4.2 quarts, depending on the specific condition. The differential lubrication for the front unit with the 0BK axle code requires 1.9 pints of the appropriate AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube. Maintaining these specific volumes and fluid types ensures that the S8’s all-wheel-drive system and powertrain function smoothly. AMSOIL’s synthetic formulations are designed to extend the life of these components, reducing the frequency of top-offs and preventing the sludge and wear that can plague high-mileage luxury vehicles.
About the Vehicle
The 2018 Audi S8 is a benchmark in the luxury performance sedan segment, distinguished by its ability to blend everyday practicality with supercar-level performance. Built on the Volkswagen Group’s premium architecture, this model is powered by a 4.0-liter twin-turbocharged V8 engine, known as the DDTA 9 engine code. This powerplant is a marvel of engineering, delivering substantial horsepower and torque figures that allow the S8 to sprint from 0 to 60 mph in a matter of seconds. The engine’s design incorporates advanced technologies like direct injection and a sophisticated variable valve timing system to optimize efficiency without sacrificing power.
Owners of the S8 value its dual nature as a comfortable daily driver and a high-speed performance machine. The interior is typically appointed with the finest materials available in the Audi lineup, featuring advanced technology, spacious seating for five, and a trunk that can accommodate luggage for long trips. The vehicle’s Quattro all-wheel-drive system provides exceptional traction and handling stability in various weather conditions, making it a reliable choice for year-round driving in diverse climates. The suspension geometry is tuned to offer a balance between a compliant ride quality for city streets and firm control during spirited driving on winding roads.
Despite its robust build quality, high-performance vehicles like the S8 are not immune to specific issues that can arise over time, particularly when subjected to extreme conditions or long-term use. One common concern for this platform involves the oil pump and oil pan assembly, which can sometimes be prone to leaks or wear. Using a high-quality synthetic oil like the AMSOIL 5W-40 MS or 0W-40 FS variants helps mitigate this risk by providing a superior protective film that reduces wear on bearings and gears. Another area of focus is the cooling system; extreme heat generated by the twin turbos can place significant stress on the radiator and hoses. The extended protection offered by AMSOIL antifreeze coolants helps prevent corrosion and scale buildup, ensuring the cooling system remains efficient under heavy thermal loads.
Turbocharger health is another critical aspect of the S8’s longevity. The high-heat operation of the turbos can degrade conventional oils over time, leading to coking and reduced lifespan. Synthetic oils maintain their stability at extreme temperatures, preventing the formation of deposits that can starve the turbo bearings of lubrication. Furthermore, the 8-speed automatic transmission requires fluid that can handle rapid shifts and high torque loads. Over time, transmission fluid can lose its viscosity, leading to harsh shifting or wear in the valve body. Regular changes with a premium synthetic transmission fluid can preserve the transmission’s smooth operation and responsiveness, extending the service life of this complex component.
Finally, carbon buildup on intake valves is a known issue in direct injection engines, including the 4.0L TFSI unit in the S8. This accumulation can reduce airflow and power. Periodic use of a high-quality fuel additive like AMSOIL P.i. Performance Improver helps clean fuel injectors and intake valves, maintaining the engine’s efficiency and performance. By addressing these specific needs with premium lubricants, owners can ensure their 2018 Audi S8 continues to deliver the exceptional performance and reliability that defines the brand.
Vehicle Maintenance and Care
Maintaining the 2018 Audi S8 requires a proactive approach to fluid health. Regular inspections should include checking the oil level, as the engine may consume small amounts of oil under heavy loads. The transmission fluid level should also be monitored, though it is a sealed system for the most part. For the differential, inspect the gear lube for contamination or leaks, especially after off-road driving or track events where thermal loads are highest. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is hygroscopic, meaning it absorbs moisture from the air over time, which can lower its boiling point and affect braking performance; flushing this fluid with a DOT 3 and DOT 4 synthetic brake fluid ensures consistent pedal feel and ABS operation.
Seasonal maintenance is also crucial for this vehicle. During winter, the low-temperature flow properties of the 0W-40 or 5W-40 oils become particularly important to ensure the engine starts quickly and lubricates immediately. In summer, the high-temperature stability prevents the oil from breaking down under the heat of stop-and-go traffic or high-speed cruising. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant system should be inspected for proper concentration to prevent freezing in cold climates and boiling in hot ones. Using the correct AMSOIL products ensures that all these systems work in harmony, protecting the significant investment in this luxury performance sedan.
By adhering to a strict maintenance schedule using the recommended AMSOIL fluids, S8 owners can enjoy the full potential of their vehicle’s capabilities. The synergy between the engine, transmission, and drivetrain is best preserved when each component is bathed in the highest quality lubricants available. This approach not only enhances performance but also safeguards against premature wear, ensuring that the 2018 Audi S8 remains a joy to drive for years to come. Whether for daily commuting or occasional spirited driving, the right fluids make all the difference in the longevity and satisfaction of owning this exceptional automobile.