The 2018 Audi S4 with the 3.0L 6-cylinder turbocharged engine (Engine Code CWGD B) demands lubricants that meet rigorous European standards. Factory specifications for this high-performance sedan are precise, requiring specific viscosity grades and fluid types to ensure longevity and protect against the extreme thermal and mechanical stresses of turbocharged operation. Using fluids that do not meet Audi and Volkswagen quality standards can lead to premature wear, sludge buildup, and compromised engine performance. Proper lubrication extends the life of critical components, maintains fuel efficiency, and ensures the driving dynamics that owners expect from the S4 platform.
Recommended AMSOIL Products
- AMSOIL 0W-20 LS-VW 100% Synthetic European Motor Oil – A specialized formula designed for the unique demands of gasoline, diesel, and hybrid European vehicles, meeting necessary Audi and Volkswagen standards.
- MANN-FILTERS Oil Filter – Premium filtration media that offers improvements over original equipment manufacturer-branded filters to ensure clean oil flow.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid (OAT) formulation that protects cooling system metals, gaskets, and hoses for up to 150,000 miles.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands heavy towing, elevated temperatures, and challenging terrain while providing superior protection for the 8-speed transmission.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – An alternative synthetic transmission fluid that protects against wear and maintains fuel economy for automatic transmissions.
- 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.
Ensuring the correct oil capacity is just as critical as selecting the right product. The 2018 Audi S4 3.0L engine requires 7.7 quarts of oil when a filter change is included. It is vital to check the oil level after refilling to guarantee the system is operating within the manufacturer’s specifications. The torque specification for the oil drain plug is 22 ft-lbs, and owners should replace the drain plug seal during every service to prevent leaks and ensure a secure fit.
For the cooling system, the 2018 S4 holds 10.6 quarts of AMSOIL Passenger Car & Light Truck Antifreeze & Coolant. The vehicle benefits from high-quality antifreeze that exceeds OEM requirements without containing phosphates, nitrates, or other corrosive elements. AMSOIL offers both pre-mixed and concentrated options to suit different maintenance preferences, ensuring the engine remains cool even under the high thermal load of the twin-scroll turbocharger.
The automatic transmission in the 2018 Audi S4 is an 8-speed unit (0D5). Total fill capacity is 9.1 quarts, while the initial fill capacity is approximately 3.8 quarts. Actual capacity can vary slightly between 3.6 and 4.0 liters (3.8 to 4.2 quarts) depending on the specific batch and service conditions. Using a high-performance synthetic fluid here is crucial to prevent torque converter issues and ensure smooth shifting, especially given the car’s performance-oriented nature.
Transmission and Differential Fluids
The performance of the S4’s powertrain relies heavily on the quality of fluids circulating through its transmission and differential systems. The vehicle utilizes a front differential (0D5) which requires 1.9 pints of lubricant. While the differential often shares similar requirements with the transmission in some platforms, it is essential to verify the specific lubricant grade. The AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is recommended for both the transmission and differential applications, providing a robust barrier against wear and thermal degradation.
For drivers who prefer a slightly more economical option that still delivers 100% synthetic protection, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is a viable alternative. It is engineered to protect against wear and maintain fuel efficiency, making it a practical choice for daily driving while still meeting the demands of the S4’s sophisticated 8-speed transmission.
AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid and Seasonal Maintenance
Brake systems on performance vehicles like the S4 are subject to high heat and frequent use. The 2018 Audi S4 specifies a DOT 4 hydraulic brake fluid. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is compatible with DOT 3 and DOT 4 requirements, offering a stable viscosity range that ensures crisp pedal feel and rapid ABS activation. This fluid helps maintain the integrity of the braking system, reducing the risk of boil-over during spirited driving or track use.
For vehicles that see seasonal storage or long periods of inactivity, AMSOIL offers AMSOIL Gasoline Stabilizer, which keeps fuel fresh for up to 12 months and protects against varnish buildup. Additionally, AMSOIL Engine Fogging Oil can be used to coat internal engine components, preventing rust and corrosion during storage. These products ensure that when the S4 is ready to be driven again, the engine and fuel system start reliably.
Carbon buildup is a known issue with direct injection engines and turbochargers. The use of AMSOIL P.i. Performance Improver can help restore fuel injectors to 100% flow rate and restore up to 14% of horsepower, reducing the need for more expensive services. Furthermore, the AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor helps lubricate the fuel system and upper cylinders, complementing the cleaning action of the gasoline additive.
About the Vehicle
The 2018 Audi S4 represents a pinnacle of performance sedans, blending daily drivability with track-ready capabilities. Powered by a 3.0-liter supercharged V6 engine (identified by Engine Code CWGD B), this vehicle delivers a potent combination of acceleration and refined handling. The S4 is part of the B9 generation of the Audi A4 platform, which is renowned for its lightweight construction and advanced Quattro all-wheel-drive system. This powertrain configuration allows the S4 to offer a driving experience that is both exciting and composed, suitable for everything from highway commuting to canyon carving.
The engine’s design features a twin-scroll turbocharger, which helps minimize lag and provides responsive power delivery across the rev range. The vehicle’s interior and technology suite are equally impressive, offering a driver-focused cockpit equipped with the latest infotainment and safety features. The S4 appeals to drivers who require a practical vehicle that does not compromise on performance, making it a favorite among enthusiasts who value German engineering precision.
Despite its robust design, the 2018 Audi S4 can benefit from preventive maintenance strategies that address common issues. First, the direct injection system can lead to carbon buildup on intake valves over time, which can affect performance and fuel economy. High-quality synthetic oils and fuel additives designed to clean injectors can significantly mitigate this issue.
Second, the high-temperature environment created by the turbocharger and the performance-oriented nature of the car can stress the cooling system. Maintaining a robust cooling system with a high-performance antifreeze is essential to prevent overheating, which can lead to costly repairs. Third, the 8-speed automatic transmission can experience shuddering or hesitation if the fluid degrades or becomes contaminated. Using a premium synthetic transmission fluid designed for European specifications ensures smooth shifts and extends the life of the transmission.
Finally, the brake system is subjected to significant thermal loads during spirited driving. Brake fluid can absorb moisture over time, leading to a spongy pedal feel and reduced braking performance. Regular fluid flushes with a high-quality synthetic brake fluid maintain the fluid’s boiling point and ensure consistent braking power, keeping the vehicle safe and responsive.
By addressing these potential areas of concern with high-performance lubricants and additives, owners can ensure that their 2018 Audi S4 remains in peak condition. The investment in premium fluids not only protects the vehicle’s value but also enhances the driving experience, allowing the owner to fully enjoy the capabilities of this sophisticated German sports sedan.