Proper lubrication extends the life of your engine significantly. The 6.0-liter M275 5 engine is a twin-turbocharged unit that operates under intense pressure. Standard conventional oils often break down quickly under these conditions, leading to sludge formation and increased wear. AMSOIL synthetic motor oils are engineered with a precise blend of base stocks and premium additives that resist oxidation and thermal breakdown. This ensures that your engine receives consistent protection even when pushed to its performance limits. With a total oil capacity of 9.5 quarts (including the filter), it is vital to use the correct quantity and type of fluid to ensure the lubrication pump can circulate effectively throughout the engine and the turbocharger system.
Be mindful that models equipped with an external oil cooler may require additional oil to fill the cooler lines properly. Always allow the engine to rest for five minutes after refilling or shutting down before checking the dipstick, as oil needs time to drain back into the sump for an accurate reading. The drain plug should be torqued to 22 ft-lbs to ensure a secure seal without damaging the threads. Maintaining the correct viscosity is key; whether you choose the 5W-40 or the 0W-40 grade, the synthetic formulation ensures optimal flow in all temperatures while maintaining a strong film strength when the engine is at peak operating temperature.
The cooling system on a vehicle of this magnitude is equally critical. With a total capacity of 14.7 quarts, the cooling system must effectively dissipate the immense heat generated by the twin turbos and the V12 configuration. AMSOIL’s antifreeze and coolant options are designed to protect against corrosion in the aluminum components typical of modern Mercedes engines. Whether you select the convenient pre-mixed Passenger Car & Light Truck Antifreeze or the concentrated Propylene Glycol option, you gain protection that can last up to 150,000 miles or five years, whichever comes first. This longevity reduces the frequency of flushes and helps prevent the internal degradation that can lead to expensive overheating repairs.
Transmission and Differential Care
The automatic transmission in the 2008 S65 AMG is a high-performance unit, likely the 722.6 model, requiring a fluid that can handle sudden shifts and heavy loads. A total fill for this transmission requires 8.5 quarts, while an initial fill (drain and refill) utilizes about 6.9 quarts. Using a dedicated synthetic transmission fluid like the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid ensures that the fluid remains fluid in sub-zero temperatures and resists shear breakdown during heavy towing or spirited driving. It provides a protective barrier against wear, preventing the sludge and varnish that can clog delicate valve bodies and torque converters. The OE Fuel-Efficient option is also a robust choice for those looking for high-performance protection that meets original equipment standards.
While the S65 AMG focuses on front-engine, rear-wheel-drive dynamics, rear differential lubrication is still a consideration for the 3.4 pints capacity noted for the rear axle. Although specific AMSOIL fluid links for the differential were not provided in the primary list, maintaining the rear gear lubricant is essential for the smooth operation of the drivetrain components. Ensuring the differential fluid is at the correct level and condition helps maintain the precise alignment and load-bearing capacity required for a heavy luxury sedan.
Brake fluid is often overlooked until a problem arises, but for a vehicle with the stopping power of an S65 AMG, brake system integrity is paramount. The factory specification requires DOT 4 Plus or products approved on MB Sheet 331.0. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid exceeds these requirements, offering a stable viscosity across a wide temperature range. This stability is crucial for maintaining consistent pedal feel and preventing boil-over under the heavy braking loads encountered with a vehicle of this weight and speed potential. Additionally, the power steering system benefits from the 100% Synthetic Multi-Vehicle Power Steering Fluid, which resists heat and prevents leaks by keeping seals soft and pliable.
About the Vehicle
The 2008 Mercedes-Benz S65 AMG represents the pinnacle of luxury sedan engineering from the early 21st century. Part of the W221 generation, which was introduced in 2005 and produced through 2013, the S-Class has long been the benchmark for comfort, safety, and technological advancement in the automotive world. The S65 AMG, however, distinguishes itself as the ultimate performance variant within the S-Class lineup, featuring the legendary AMG-tuned version of the 6.0-liter V12 engine.
This powerplant, known internally as the M275 5, is a twin-turbocharged unit that produces roughly 621 horsepower, delivering a massive amount of torque. The engineering behind this engine allowed it to generate such power smoothly, often described as “rocket-like” acceleration without the jerky character of smaller, high-revving supercharged V8s. The S65 AMG combines this brute force with the plush, isolation-focused suspension tuning typical of the S-Class, creating a driving experience that is both terrifyingly fast and remarkably serene. It sits atop the hierarchy of the W221 chassis, offering a blend of exclusivity and raw power that appeals to enthusiasts who want a grand tourer rather than a track-focused sports car.
Owners of the 2008 S65 AMG value this vehicle for its sheer presence on the road and its ability to serve as a highly capable executive limousine when the driver wishes to relax. The interior craftsmanship, featuring Nappa leather, wood trim, and advanced infotainment systems for its time, matches the exterior quality. However, maintaining such a sophisticated machine requires an owner who understands the specific needs of its components. The heavy weight of the car, combined with the immense power output, places unique stresses on the drivetrain, brakes, and cooling systems. Proper maintenance using high-performance synthetic lubricants is the most effective way to preserve this unique combination of luxury and performance, ensuring that the vehicle remains a reliable and enjoyable possession for years to come.
Additional Maintenance Products
For owners who store their vehicles seasonally or wish to maximize engine efficiency, AMSOIL offers a range of additives and protectants. The P.i. Performance Improver is a potent gasoline additive that can restore up to 14% horsepower by cleaning fuel injectors and removing carbon buildup. For those concerned with long-term storage, the Engine Fogging Oil provides excellent rust prevention for internal components, ensuring the engine is ready to start after a period of inactivity. Fuel Stabilizer can keep the gasoline fresh for up to 12 months, protecting against varnish and gum buildup, which is particularly useful for vehicles that are not driven daily. Finally, car care products like the Miracle Wash Waterless Wash and Wax Spray allow you to maintain the pristine appearance of your S-Class without harsh detergents, while the High-Foam Car Shampoo offers a deep clean for those preferring traditional washing methods.