The 2009 Mercedes-Benz SLK300 with its 3.0L V6 engine (code 272.942 Z) is a sophisticated roadster that demands fluids designed specifically for European engineering tolerances. Using the correct lubricants ensures optimal performance, protects against premature wear, and maintains the vehicle’s fuel efficiency. Because this engine relies on precise oil film strength and the transmission operates with specific friction modifiers, choosing a generic oil filter and fluid can compromise the driving experience and long-term reliability of the SLK300.
Recommended AMSOIL Products
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – Formulated with a European-specific additive blend to meet the rigorous specifications of the 272.942 Z engine, offering superior protection against high-temperature stress and engine wear.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An excellent alternative for extreme cold weather start-ups, providing rapid flow to critical engine components while maintaining stability in high heat.
- AMSOIL Oil Filter – Engineered for extended service intervals, this filter captures 99 percent of contaminants down to 20 microns, protecting the engine from wear-causing debris more effectively than standard filters.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A premium fluid designed for the 7-speed automatic transmission, remaining fluid in sub-zero temperatures while withstanding the heat of heavy towing and challenging terrain.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – An optimal choice for everyday driving, offering strong protection against wear and friction for smooth shifting operations.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A pre-mixed, phosphate- and silicate-free formula that exceeds OEM requirements, protecting the cooling system for up to 150,000 miles or five years.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Specifically recommended for the SLK300’s braking system, this fluid offers excellent ABS responsiveness and a stable viscosity range to prevent brake fade.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Designed to reduce friction and prevent leaks by keeping seals soft, ensuring quiet and responsive steering in this roadster.
- MANN-FILTERS Air Filters – A top-tier replacement that provides premium media filtration to ensure the 3.0L engine breathes clean air for optimal combustion and power output.
When performing maintenance on the SLK300, understanding the specific capacities of the engine is crucial to avoiding underfilling or overfilling, both of which can cause serious mechanical damage. For the 3.0L V6 engine (code 272.942 Z), the oil capacity is 8.5 quarts when a filter change is included. It is important to note that on models equipped with an oil cooler, additional oil may be required if the cooler is drained during service. After refilling, owners should allow the engine to sit for five minutes before checking the oil level to ensure an accurate reading on the dipstick. The oil drain plug should be torqued to 22 ft/lbs to ensure a secure seal without damaging the threads.
The cooling system is equally critical for this high-performance European vehicle. The Antifreeze & Coolant capacity for the 2009 SLK300 is 10.4 quarts. AMSOIL offers two primary options for this fluid. The Passenger Car & Light Truck Antifreeze & Coolant is a ready-to-use, 50/50 pre-mix formulation that protects all metals, gaskets, and hoses in the cooling system. Alternatively, the Propylene Glycol Antifreeze & Engine Coolant is a concentrated option that requires mixing with distilled water, offering extended protection up to 150,000 miles or five years. Both formulations are free from phosphates, nitrates, nitrites, silicates, borates, and amines, ensuring compatibility with the vehicle’s materials while providing superior corrosion protection.
The automatic transmission in the SLK300 is a 7-speed unit (722.9 series) that requires specific fluid formulations to operate correctly. Depending on the data card configuration—specifically regarding code A89 for reduced friction—the capacity for a total fill is 9.5 quarts. For vehicles without the specific reduced-friction code, or for those seeking maximum performance, the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is the ideal choice. It remains fluid in sub-zero conditions and provides reserve protection during heavy use. For those preferring a standard OE-style synthetic, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid provides robust protection against wear while maintaining fuel economy.
Braking performance on a lightweight roadster like the SLK300 is paramount. The vehicle recommends a DOT 4 Plus specification, which can be identified by the Mercedes-Benz part number 0009895605090109 or products approved on MB Sheet 331.0. AMSOIL’s DOT 3 and DOT 4 100% Synthetic Brake Fluid meets these strict requirements, providing a stable viscosity over a wide temperature range. This stability ensures excellent responsiveness for both the anti-lock braking system (ABS) and traction control, giving the driver confidence in all weather conditions. The fluid resists boiling under heavy braking and prevents the system from becoming spongey over time.
Beyond the engine and transmission, proper maintenance of other fluid systems contributes significantly to the longevity of the vehicle. The power steering system benefits from AMSOIL’s 100% Synthetic Multi-Vehicle Power Steering Fluid. This fluid is engineered to prevent seal drying and leaking, reducing friction for quieter operation and extending the life of the steering pump and rack. Additionally, for owners who drive their SLK300 seasonally or store it for extended periods, AMSOIL Gasoline Stabilizer helps keep fuel fresh for up to 12 months, preventing varnish and gum buildup that can clog injectors. During storage, Engine Fogging Oil can be used to coat internal components and prevent rust, ensuring the engine is ready to run smoothly when the season returns.
Filter selection is just as important as fluid choice. The AMSOIL Oil Filter is designed to work in tandem with the synthetic oils, utilizing a media that captures small wear-causing contaminants. It offers lower flow restriction compared to standard filters, allowing oil to circulate freely to protect the high-stress bearings of the V6 engine. For those who prefer original equipment manufacturer (OEM) branded filters, the WIX Oil Filter and MANN-FILTERS Oil Filter are also excellent choices, both offering premium media that surpasses OEM specifications for filtration efficiency. Similarly, the MANN-FILTERS Air Filter ensures the engine receives clean air, which is essential for maintaining the efficiency and power output of the 3.0L engine.
Finally, keeping the vehicle clean and protected from the elements is an essential part of ownership. Using a specialized cleaner like AMSOIL Brake and Parts Cleaner helps remove brake dust and road grime from wheels without damaging the finish, while the Heavy-Duty Degreaser tackles stubborn oil and tar on the engine bay. For exterior protection, the Exterior Ceramic Spray provides a durable, water-shedding layer that guards against UV rays and environmental contaminants. These care products complement the mechanical maintenance, ensuring the 2009 SLK300 looks as sharp as it performs.
About the Vehicle
The 2009 Mercedes-Benz SLK300 represents a specific era of the R171 generation, a model line known for its retractable hardtop design that combined the open-air driving experience of a roadster with the security of a coupe. Powered by the M272 3.0-liter V6 engine, this vehicle delivers a smooth, linear power delivery that is characteristic of German engineering from the late 2000s. The engine code 272.942 Z indicates the specific calibration and emissions configuration for that model year, producing approximately 228 to 229 horsepower. This powertrain was paired with a robust 7-speed automatic transmission (7G-Tronic) that offered both manual and automatic shifting modes, allowing for a sporty yet comfortable driving dynamic.
Owners of the SLK300 often appreciate its balanced handling and distinctive styling, which features a sleek aluminum hood and a compact footprint that makes it agile in urban environments. The R171 platform was the first to feature a steel retractable hardtop that opened in about 22 seconds, a technological highlight that set it apart from competitors at the time. While the vehicle is designed for spirited driving, the engine is renowned for its smoothness and durability, provided it receives the high-quality lubrication it was engineered for. The SLK300 holds a reputation as a stylish daily driver that offers a unique blend of practicality and luxury, making it a popular choice for enthusiasts who value both performance and comfort.