Proper lubrication is the cornerstone of reliability for high-performance machines like the 2008 BMW M5. Powered by the legendary S85 V10 engine, this vehicle operates under extreme thermal and mechanical stress. Standard off-the-shelf fluids often degrade when exposed to the sustained high RPMs and intense heat generated by the naturally aspirated V10 powerplant. Utilizing the correct high-grade synthetic lubricants ensures that critical components are protected against wear, oxidation, and sludge formation, maintaining the vehicle’s precision handling and engine responsiveness for the long haul.
Recommended AMSOIL Products
To ensure your BMW M5 receives the protection it demands, the following AMSOIL products are specifically recommended based on factory specifications and performance requirements:
- AMSOIL 10W-60 FS 100% Synthetic European Motor Oil – A specialized European formula featuring a precise blend of synthetic base oils and premium additives designed for high-performance engines, providing exceptional protection under extreme temperatures.
- MANN-FILTERS Oil Filter – Engineered with premium media that offers improvements over standard OEM filters, ensuring maximum flow and filtration efficiency for the 5.0L V10 engine.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid (OAT) formulation that protects the cooling system metals, gaskets, and hoses, compatible with all antifreeze colors and offering protection up to 150,000 miles or 5 years.
- 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, ideal for the high-performance braking systems of the M5.
- AMSOIL SEVERE GEAR® 75W-140 100% Synthetic Gear Lube – Specifically formulated for limited-slip differentials, this fluid contains friction modifiers that help reduce operating temperatures and control thermal runaway while extending oil and seal life.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – An advanced protection against wear for standard rear differential applications, protecting against rust and corrosion while helping to reduce operating temperatures.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Formulated to reduce friction and keep seals soft to prevent leaks, ensuring quiet operation and excellent high-temperature performance for the M5’s power steering system.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Withstands the rigors of heavy towing, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions to promote smooth, shudder-free shifts.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – A cost-effective alternative that protects against wear, resists sludge, and guards against leaks while promoting smooth shifts.
The engine of the 2008 BMW M5, specifically the 5.0L 10-cylinder S85 B50A 1 engine, is a masterpiece of automotive engineering. This naturally aspirated V10 was unique at the time of its production, offering a high-revving character that defined the era of high-performance sedans. Because the engine operates at significantly higher RPMs than standard V8s, the oil must maintain its viscosity index and film strength to prevent metal-to-metal contact in the valvetrain and bearings. The AMSOIL 10W-60 FS motor oil is tailored for this purpose, meeting the rigorous requirements of European performance vehicles. The system requires 9.8 quarts of oil when including a filter change, so precision in product selection is vital to ensure adequate lubrication throughout the sump and galleries.
Essential Cooling and Brake Fluids
Maintaining the thermal health of the M5 is just as critical as lubricating the moving parts. The cooling system capacity for this vehicle is 15.9 quarts, making it a substantial system that requires a coolant capable of high heat transfer and corrosion inhibition. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant offers an OAT formulation that is phosphate, nitrate, and silicate-free, ensuring compatibility with all the various metals and hoses found in the engine bay. For the braking system, which demands instant responsiveness for a vehicle of this caliber, the AMSOIL DOT 3 and DOT 4 Synthetic Brake Fluid provides a stable viscosity range. This prevents the fluid from boiling under hard cornering and braking scenarios, ensuring the pedal remains firm and the ABS system functions correctly.
Transmission and Differential Protection
The power generated by the V10 must be transferred to the road efficiently. While the specific transmission fluid is listed as needing a low viscosity DOT 4 brake fluid alternative in some maintenance notes, the recommended AMSOIL Signature Series or OE Multi-Vehicle Automatic Transmission Fluids offer superior protection against the extreme heat generated by the M5’s transmission. These fluids resist thermal breakdown and sludge, promoting smooth shifts and protecting against wear. For the rear differential, the M5 utilizes a limited-slip or standard differential depending on the specific configuration. AMSOIL SEVERE GEAR lubricants in 75W-140 and 75W-90 viscosities provide the necessary friction modifiers for limited-slip units to operate correctly, while also offering extended protection against wear and rust. The capacities for the rear differential are 2.3 pints for both limited-slip and standard configurations, making fluid management a straightforward task when using these high-quality products.
Additional Maintenance and Care
For owners who store their M5 or wish to maximize fuel system efficiency, AMSOIL offers a range of additives and care products. The AMSOIL P.i. Performance Improver Gasoline Additive helps restore fuel injectors to 100% flow rate, which is particularly beneficial for GDI engines, and can help recover lost horsepower. The AMSOIL Engine Fogging Oil is an excellent choice for seasonal storage, providing a protective coating on internal engine components to prevent rust during periods of inactivity. Furthermore, the AMSOIL 100% Synthetic Power Steering Fluid ensures the hydraulic components of the steering system remain pliable and leak-free, contributing to the precise handling the M5 is famous for. Regular use of these products ensures that every aspect of the vehicle, from the engine block to the wheel hubs, receives the highest level of protection available.
About the Vehicle
The 2008 BMW M5 represents a pinnacle in the history of high-performance sedans. Part of the E60 generation, this vehicle was distinguished by its heart: the S85 V10 engine. This engine was not a turbocharged powerplant like many of its contemporaries but a naturally aspirated V10 that produced 500 horsepower and revved to an impressive 8,000 RPM. The distinct sound of the V10 has become legendary among automotive enthusiasts, often cited as one of the best engine notes ever produced in a production car. The M5 was designed to be a dual-purpose vehicle, capable of carrying passengers in comfort while delivering supercar-level acceleration and handling on a track.
Powered by the 5.0-liter displacement, the S85 engine was a technological marvel, featuring individual throttle bodies for each cylinder and a dry sump lubrication system to ensure oil pressure remained consistent during high-G cornering. The chassis was built on the E60 platform, which was already renowned for its engineering, but the M5 took it further with adaptive suspension, stiffer dampers, and massive brake rotors to handle the immense speed. Owners of this vehicle appreciate its raw, unfiltered driving character and the sheer engineering effort put into creating a sedan that could compete with dedicated sports cars. Despite its age, the M5 remains a collector’s item and a favorite for those who value analog driving feel combined with modern luxury. Its legacy is defined by the unique acoustic experience of the V10 engine and its ability to deliver exhilarating performance without the need for forced induction.