The 2008 Audi S4 with the 4.2L V8 (Engine Code BHF B) is a high-performance grand tourer that demands precise lubrication to maintain its power and longevity. This engine, known for its aggressive power delivery and high-revving nature, operates under significant thermal stress. Using the correct viscosity and meeting the strict Audi/Volkswagen oil quality standards is essential to prevent wear and ensure optimal performance. AMSOIL synthetic lubricants are formulated to exceed these factory requirements, offering superior protection against the extreme temperatures and severe service conditions often associated with driving a performance sedan.
Recommended AMSOIL Products
- AMSOIL 5W-40 MS 100% Synthetic European Motor Oil – Engineered specifically for the precise demands of European gasoline and diesel vehicles, featuring a blend of synthetic base oils and premium additives.
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – A fuel-efficient option designed to protect your V8 while maximizing performance and meeting Audi/VW quality standards.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – Ideal for extreme temperature variations, providing superior cold-flow properties and high-temperature stability for your Audi S4.
- MANN-FILTERS Oil Filter – Offers premium filtration media that improves upon original equipment manufacturer specifications to ensure clean oil circulation.
Engine Oil and Filtration Recommendations
Proper engine oil is the lifeblood of your 2008 Audi S4. The manufacturer specifies oils that meet strict Audi and Volkswagen quality standards. For this vehicle, the recommended viscosity grades include 5W-40, 5W-30, 0W-40, and 0W-30, depending on your climate and operating conditions. The total capacity for an oil change, including the filter, is 9.3 quarts. It is crucial to check the oil level after refilling and torque the oil drain plug to 47 ft/lbs to prevent leaks.
AMSOIL offers three distinct European motor oils tailored for this application. The AMSOIL 5W-40 MS is a premium formulation designed for the unique demands of European vehicles. It balances protection with performance, making it an excellent choice for those seeking the highest level of wear protection. If you prefer a slightly more fuel-efficient blend without sacrificing protection, the AMSOIL 5W-40 FS is a robust alternative that meets all necessary OEM standards. For drivers facing extreme cold winters or heavy towing conditions, the AMSOIL 0W-40 FS provides outstanding low-temperature fluidity and high-temperature stability, ensuring the engine is protected from the moment you turn the key.
Pairing your synthetic oil with a high-quality filter is equally important. The recommended filter for this engine is the MANN-FILTER Oil Filter. This filter utilizes premium media that improves upon the performance of standard OEM-branded filters, ensuring that contaminants are effectively removed from the oil supply to extend engine life and maintain power.
Transmission and Differential Fluids
The 2008 Audi S4 typically comes equipped with a sophisticated transmission system that requires precise fluid properties to operate smoothly. Whether you have the automatic or manual transmission, using the wrong fluid can lead to premature wear, shifting issues, and costly repairs.
For the automatic transmission (6-speed 09L), the total fill capacity is 10.4 quarts, while an initial fill requires approximately 8.5 quarts. AMSOIL recommends Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid for maximum protection. This fluid withstands the rigors of heavy towing, elevated temperatures, and challenging terrain, ensuring smooth shifting even under stress. For those seeking a high-performance alternative that focuses on OE-compliant wear protection, the OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is an excellent choice.
If your Audi S4 is equipped with a manual transmission, the system requires AMSOIL 75W-90 Manual Transmission & Transaxle Gear Lube. This synthetic lube is designed to protect brass synchronizers, offer outstanding cold-flow properties, and resist heat and pressure. The capacity for the manual transmission is approximately 6.8 pints.
The differential and transfer case also require specialized lubrication to handle the power generated by the 4.2L V8. The Center Differential (Transfer Case) has a capacity of 1.1 pints, while the Front Differential (with Automatic Transmission) holds 2.3 pints, and the Rear Differential holds between 1.9 and 3.2 pints depending on the specific axle code (01R or 0AR). For all differential applications, AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube is recommended. This fluid is specifically engineered for high-load gear and bearing protection, offering better cold-weather shifting, improved efficiency, and extended seal life to prevent leaks.
Coolant, Brake Fluid, and Power Steering
Maintaining the cooling system is vital for the longevity of your Audi’s engine, especially given its high-performance nature. The cooling system capacity for the 2008 S4 is 12.9 quarts. You can use either AMSOIL Passenger Car & Light Truck Antifreeze & Coolant, which is a 50/50 pre-mix formulation offering protection up to 150,000 miles or 5 years, or the concentrated AMSOIL Propylene Glycol Antifreeze and Engine Coolant, which requires mixing with distilled water and offers even longer service intervals. Both formulations are phosphate-, nitrate-, and silicate-free, ensuring compatibility with all cooling system metals and hoses.
For the braking system, the vehicle requires Hydraulic Brake Fluid, DOT 4 specification. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is an ideal replacement, providing excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range to prevent brake fade during spirited driving.
The power steering system for this model benefits from AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid. This fluid helps seals remain soft to prevent leaks, resists heat for long fluid life, and offers strong anti-wear protection. It is formulated for quiet operation, ensuring smooth and silent steering input even in extreme temperatures.
Maintenance Schedule and Additional Protection
Extending the service intervals of your vehicle without compromising protection is a key advantage of using AMSOIL synthetic lubricants. By adhering to the recommended products, you can maximize the time between maintenance while ensuring your Audi S4 remains in peak condition. For owners looking to keep their vehicle fresh during storage or winter months, AMSOIL offers AMSOIL Gasoline Stabilizer to keep fuel fresh for up to 12 months and AMSOIL Engine Fogging Oil to protect internal engine components from rust during long periods of inactivity.
To ensure the fuel system is operating at peak efficiency, AMSOIL P.i.® Performance Improver Gasoline Additive is highly recommended. This additive restores up to 14% horsepower by cleaning fuel injectors and preventing carbon buildup, which is particularly beneficial for GDI engines and those running high-mileage vehicles. For exterior care, the AMSOIL High-Foam Car Shampoo and AMSOIL Exterior Ceramic Spray provide a durable, protective finish that guards against UV rays and road grime, keeping the S4 looking pristine.
About the Vehicle
The 2008 Audi S4 represents a significant moment in the lineage of the S4 sedan, blending everyday usability with genuine performance capabilities. Built on the B7 platform, this model is powered by a naturally aspirated 4.2-liter V8 engine, identified by the engine code BHF B. This engine was a standout in its class, delivering robust horsepower and a smooth, linear power delivery that distinguished it from many of its turbocharged competitors at the time. The S4 was renowned for its Quattro all-wheel-drive system, which provided exceptional traction and handling stability in various weather conditions, making it a favorite among enthusiasts who demanded reliability alongside speed.
Inside the cabin, the S4 offered a blend of luxury and driver-focused ergonomics, featuring high-quality materials and advanced technology for its era. The vehicle was designed to be a practical grand tourer, offering ample space for passengers and cargo while maintaining a sporty driving character. Owners of the 2008 S4 often appreciate the robustness of the 4.2L V8, which is known for its durability when properly maintained. The combination of the powerful engine, sophisticated Quattro drivetrain, and refined build quality made the S4 a top choice for those seeking a premium performance sedan that could handle both daily commutes and weekend drives with equal aplomb. Regular maintenance with high-quality synthetic lubricants ensures that this powerful machine continues to deliver its signature performance and reliability for years to come.
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