The 2008 Mercedes-Benz SL55 AMG is a high-performance grand tourer that demands the utmost in lubrication quality. Under the hood lies the M113 engine, a 5.5-liter naturally aspirated V8 with the specific engine code 113.995 S. This powertrain generates significant heat and operates at high RPMs, placing unique stresses on engine components that standard mineral oils cannot handle. Proper lubrication is critical not just for extending engine life but for maintaining the precise tolerances required for this European engineering marvel to perform as intended. Using the correct viscosity and additive package ensures that the engine remains protected against wear, thermal breakdown, and deposit formation, regardless of whether the vehicle is being driven on a highway or navigating city traffic.
Recommended AMSOIL Products
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – This specialized fluid is designed specifically for the precise demands of European vehicles like the SL55 AMG, offering a blend of synthetic base oils and premium additives that exceed OEM standards.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An alternative European formula that provides excellent cold-start protection while maintaining superior high-temperature stability for this high-output V8 engine.
- AMSOIL Oil Filter – Engineered to provide a filtering efficiency of 99 percent at 20 microns, this filter helps remove contaminants and supports extended service intervals for the SL55 AMG.
- WIX Oil Filter – A premium aftermarket option that offers improvements over original equipment manufacturer-branded filters for the SL55 AMG.
- MANN-FILTERS Oil Filter – Another high-quality filter option that provides premium media for enhanced protection.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Formulated to withstand the rigors of heavy towing and elevated temperatures, this fluid ensures smooth shifting and long-term protection for the 722.6 transmission.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A cost-effective synthetic option that protects against wear and maintains fluid stability for the automatic transmission in demanding driving conditions.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – An OAT formulation that provides protection up to 150,000 miles or 5 years, safeguarding cooling system metals, gaskets, and hoses from corrosion.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option that allows for flexible mixing ratios while offering exceptional corrosion protection.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with stable viscosity over a wide temperature range, meeting DOT 4 plus specifications required for this vehicle.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Reduces friction, helps seals remain soft to prevent leaks, and offers strong anti-wear protection against heat.
- AMSOIL Gasoline Stabilizer – Keeps fuel fresh for up to 12 months, protecting against varnish and ethanol corrosion for stored vehicles.
- AMSOIL P.i. Performance Improver – Restores lost horsepower and improves fuel economy by cleaning fuel injectors.
- AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor – Provides essential lubrication for the fuel system and upper cylinders, ensuring smooth operation and reduced wear.
Engine Oil Selection and Service Intervals
For the 5.5-liter M113 engine found in the 2008 SL55 AMG, maintaining the correct oil volume is essential for proper lubrication. The engine requires a total capacity of 9.0 quarts when the AMSOIL Oil Filter or a WIX Oil Filter is replaced. It is important to note that on models equipped with an external oil cooler, additional oil may be necessary if the cooler system is drained during the service procedure. To ensure accurate oil levels, drivers should allow at least five minutes for the oil to drain back into the pan after refilling or turning the engine off before checking the dipstick. The torque specification for the oil drain plug is 22 ft/lbs, a detail that helps prevent stripping the threads during maintenance. When selecting between the available AMSOIL options, both the 5W-40 FS and 0W-40 FS viscosities are suitable for this European engine, with the choice often depending on the prevailing ambient temperatures and driving habits.
Transmission Fluid for the 7-Speed Automatic
The SL55 AMG utilizes the robust 722.6 five-speed automatic transmission, which is a critical component for delivering power to the rear wheels. This transmission requires a specialized fluid to handle the heat generated during spirited driving. The total fill capacity for the 722.6 transmission is 9.1 quarts. Regular replacement of the transmission fluid is vital to prevent sludge buildup, ensure smooth gear engagement, and protect internal clutch packs from wear. The AMSOIL Signature Series and OE Fuel-Efficient synthetic transmission fluids are both engineered to resist thermal breakdown and maintain fluidity in sub-zero temperatures, providing reserve protection during heavy use and extended intervals between changes.
Cooling System and Brake Fluid Maintenance
Given the high output of the SL55 AMG, the cooling system works harder than average to maintain optimal operating temperatures. The system holds 12.7 quarts of Antifreeze & Coolant. Using a high-quality antifreeze is crucial to prevent overheating, which can lead to catastrophic engine damage. The AMSOIL Propylene Glycol Antifreeze and Engine Coolant is a concentrated option that offers protection up to 150,000 miles and surpasses standards for metallic corrosion. Furthermore, the braking system on this high-performance coupe requires high-temperature stability. The vehicle is designed to use DOT 4 plus fluid, which can be met by the AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid. This fluid ensures consistent pedal feel and responsive ABS operation, even after repeated hard stops.
Additional Fluids and Protectants
Proper maintenance extends beyond just the engine and transmission. The power steering system in the SL55 AMG benefits from AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid, which reduces friction, helps seals remain soft to prevent leaks, and offers strong anti-wear protection against heat. For owners storing the vehicle or driving in varying conditions, AMSOIL Gasoline Stabilizer can keep fuel fresh for up to 12 months, protecting against varnish and ethanol corrosion. For daily driving, the AMSOIL P.i. Performance Improver can restore lost horsepower and improve fuel economy by cleaning fuel injectors. Additionally, the AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor provides essential lubrication for the fuel system and upper cylinders, ensuring smooth operation and reduced wear.
About the Vehicle
The 2008 Mercedes-Benz SL55 AMG represents a pinnacle of grand touring engineering, combining the open-air freedom of a convertible with the raw power of a high-performance sports car. Built on the R230 platform, this model is powered by the legendary M117 V8, specifically tuned by AMG for the SL55 iteration. The 5.5-liter naturally aspirated V8 engine is renowned for its smooth power delivery and distinctive exhaust note, making it a favorite among enthusiasts who prefer linear acceleration over forced induction. The SL55 AMG was positioned as a more accessible, yet still formidable, entry into the AMG lineup, offering a blend of luxury, comfort, and track-ready performance. With its sleek roadster design, adjustable suspension, and advanced electronic stability systems, the vehicle is a favorite for long-distance travel while retaining the agility to handle twisty back roads. The interior typically features high-quality leather, wood trim, and advanced technology for its time, emphasizing a driver-focused experience without sacrificing the comfort expected of the SL class.