Maintaining the 2009 Mercedes Benz SLK55 AMG with its powerful 5.5-liter V8 engine requires a commitment to high-performance lubrication. This sports car features the 113.989.3 engine code, a configuration designed for high-revving performance and precise engineering. To ensure the longevity of this vehicle, using the correct fluids is not just about maintenance; it is about preserving the driving dynamics and mechanical integrity that define the AMG lineage. Whether you are tackling spirited canyon runs or simply commuting in stop-and-go traffic, the synthetic lubricants selected for this vehicle provide superior thermal stability and wear protection compared to standard petroleum-based alternatives.
Recommended AMSOIL Products
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – Specifically formulated for European vehicles, this oil features a precise blend of synthetic base oils designed for the unique thermal demands of the SLK55 AMG.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An excellent option for all temperatures, offering rapid flow during cold starts while maintaining a protective film at extreme engine operating temperatures.
- MANN-FILTERS Air Filters – Premium media that offers improvements over original equipment manufacturer filters, ensuring clean airflow for maximum engine efficiency.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – An ethylene glycol 50/50 pre-mix formulation that protects all cooling system metals, gaskets, and hoses for up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option that requires mixing with distilled water, providing extended protection up to 150,000 miles in passenger cars.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands the rigors of the 722.9 transmission, remaining fluid in sub-zero temperatures and providing reserve protection during heavy use.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Designed to protect against wear in automatic transmissions, offering a cost-effective alternative for OE specifications.
- 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.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Reduces friction, helps seals remain soft to prevent leaks, and offers strong anti-wear protection for the steering system.
- AMSOIL Gasoline Stabilizer – Helps keep fuel fresh for up to 12 months, protecting against varnish and gum buildup during seasonal storage.
- AMSOIL Engine Fogging Oil – A highly effective rust preventive designed to protect internal engine components during storage or long periods of inactivity.
- AMSOIL P.i. Performance Improver – Restores fuel injectors to 100% flow rate after one tank of fuel and helps improve fuel economy.
- AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor – Lubricates the fuel system and upper cylinders while preventing corrosion.
- AMSOIL Synthetic Multi-Purpose Grease – Resists thermal and oxidation degradation, ensuring long-term performance in various chassis applications.
The 2009 SLK55 AMG relies on a robust 5.5-liter V8 engine, and the first step in preserving its power is selecting the right motor oil. This engine operates at high temperatures and RPMs, requiring a fluid that can withstand shear stress while providing a thick, protective film between moving parts. The AMSOIL 5W-40 FS 100% Synthetic European Motor Oil is engineered specifically for the tight tolerances found in European gasoline and diesel engines. Whether you choose the 5W-40 or the 0W-40 variant, you are ensuring that the engine receives optimal protection during cold starts and under heavy thermal loads. The fluid capacity for this engine is 8.5 quarts when including a filter change. It is worth noting that on models equipped with an oil cooler, additional oil may be required if the cooler is drained during the service procedure. After refilling, allow approximately five minutes for the oil to settle before checking the level, and ensure the oil drain plug is torqued to the manufacturer’s specification of 22 foot-pounds.
Beyond the engine, the automatic transmission in this vehicle is a critical component that demands precise attention. The SLK55 AMG typically utilizes a 7-speed automatic transmission (code 722.9), which requires specific fluid characteristics to shift smoothly and efficiently. AMSOIL offers two primary options for this application: the Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid and the OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid. Both formulations are designed to handle the demands of the 722.9 system, with a total fill capacity of 9.2 quarts for the 7-speed unit. The Signature Series fluid is particularly notable for its ability to withstand heavy towing, elevated temperatures, and challenging terrain while remaining fluid even in sub-zero conditions. It provides a reserve of protection during heavy use, ensuring that the transmission shifts remain crisp and reliable regardless of the driving intensity.
Cooling system maintenance is equally vital for this high-performance vehicle. The engine requires a substantial amount of AMSOIL Passenger Car & Light Truck Antifreeze & Coolant, with a capacity of 11.7 quarts. Choosing the right antifreeze is essential for preventing corrosion and maintaining optimal operating temperatures. AMSOIL offers both an ethylene glycol-based pre-mix and a propylene glycol concentrate. The Passenger Car & Light Truck Antifreeze & Coolant is an OAT (organic acid technology) formulation that is compatible with all other antifreeze colors and is free of phosphates, nitrates, nitrites, silicates, borates, and amines. This ensures that the cooling system metals, gaskets, and hoses remain in top condition for up to 150,000 miles or five years. For those who prefer a concentrated solution, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers the same level of protection and requires mixing with distilled or high-quality water.
Braking and steering systems also benefit from high-quality synthetic fluids. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid for this vehicle should meet DOT 4 standards and provides excellent responsiveness for ABS and traction control systems. It maintains a stable viscosity across a wide temperature range, ensuring consistent braking performance. Similarly, the power steering system requires a fluid that resists heat and protects seals. The AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is formulated to reduce friction, keep seals soft to prevent leaks, and offer strong anti-wear protection. These fluids work together to ensure that the precise handling characteristics of the SLK55 AMG are maintained throughout the vehicle’s life.
For owners looking to extend the life of their vehicle during storage periods, AMSOIL offers specialized additives. The AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months, fighting ethanol corrosion and preventing gum buildup. Additionally, the AMSOIL Engine Fogging Oil is an effective rust preventive that should be used to protect internal components during long periods of inactivity. To further enhance engine cleanliness and performance, the AMSOIL P.i. Performance Improver can be added to the fuel tank. This additive helps restore GDI fuel injectors to 100% flow rate, potentially restoring horsepower and improving fuel economy. Regular use of these additives ensures that the vehicle remains in peak condition regardless of how frequently it is driven.
Vehicle Background
The 2009 Mercedes-Benz SLK55 AMG represents a significant chapter in the history of the brand’s roadster lineup. As part of the R171 generation, the SLK55 AMG was designed to bring the legendary AMG performance tuning to a compact, two-seater convertible. This era of the SLK is particularly cherished by enthusiasts for its distinctive hardtop retractable roof, which allowed owners to enjoy open-air driving while retaining the security and sound insulation of a coupe when needed. The vehicle is powered by the naturally aspirated M113 5.5-liter V8 engine, a powerhouse known for its linear power delivery and robust construction.
This specific model, with the engine code 113.989, was part of the AMG portfolio that combined high-performance engineering with luxury comfort. The SLK55 AMG was positioned as a premium sports car, offering a driving character that was both aggressive and refined. Unlike its turbocharged successors, the naturally aspirated V8 provided a unique auditory experience and a responsive throttle that many owners find deeply satisfying. The platform, developed by Mercedes-Benz, is renowned for its solid handling dynamics, making it a favorite on winding roads and twisty tracks alike. The exterior styling, with its sculpted lines and muscular stance, remains timeless, contributing to the vehicle’s strong market position as a collectible classic in the modern era.
Owners of the SLK55 AMG often cite the vehicle’s blend of everyday usability and track-capable performance as its defining feature. It stands as a testament to the era where naturally aspirated V8s dominated the sports car landscape before the widespread adoption of forced induction. Whether used as a weekend cruiser or a daily driver, maintaining the SLK55 AMG with the correct lubricants ensures that this engineering marvel continues to perform with the precision and reliability that Mercedes-Benz and AMG are famous for. By adhering to the recommended fluid specifications, owners can preserve the vehicle’s value and driving pleasure for years to come.