The 2008 Mercedes-Benz SL600 is a pinnacle of German engineering, featuring a powerful 5.5-liter 12-cylinder V-engine with a twin-turbocharged design. This high-performance luxury roadster demands fluids that can withstand extreme thermal loads, high RPMs, and the rigorous demands of both spirited track days and long-distance touring. Using the correct lubricants is critical to maintaining the integrity of its complex engine components, including the turbochargers, and ensuring the longevity of its sophisticated automatic transmission. AMSOIL synthetic lubricants are engineered to exceed the strictest original equipment manufacturer (OEM) specifications, providing superior protection against wear, sludge, and thermal breakdown in any driving condition.
Recommended AMSOIL Products
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – A specially formulated European-grade motor oil designed for the unique demands of the SL600’s twin-turbo V12, offering precise shear stability and thermal protection for high-stress driving.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An ideal choice for extreme cold weather starting or year-round protection, providing rapid oil flow and superior film strength for this high-output engine.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Provides exceptional protection for the 722.6 transmission against wear, thermal degradation, and fluid breakdown during heavy towing or spirited driving.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A top-tier synthetic ATF formulated to meet OE requirements, ensuring smooth shifting and extended service intervals for your automatic gearbox.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A ready-to-use 50/50 pre-mix that offers protection up to 150,000 miles, safeguarding cooling system metals, gaskets, and hoses from corrosion and freeze damage.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated, non-ethylene glycol formula that requires mixing with distilled water, offering superior safety and extended protection for your cooling system.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Designed for exceptional ABS and traction-control responsiveness with a stable viscosity over a wide temperature range, ideal for the SL600’s braking requirements.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Reduces friction and keeps seals soft to prevent leaks while providing strong anti-wear protection and heat resistance for the power steering system.
Engine Oil Specifications and Selection
The heart of the 2008 Mercedes-Benz SL600 is its 5.5-liter M275 engine code 275.95 Y Turbo V12. This powerhouse generates immense horsepower and torque, creating significant heat and stress within the crankcase. AMSOIL European motor oils are specifically developed to address the needs of these high-performance gasoline, diesel, and hybrid European vehicles. The oils feature a precise blend of synthetic base oils and premium additives that ensure the correct viscosity under all operating temperatures.
For this vehicle, the recommended oil grade is 0W-40 or 5W-40, suitable for all temperatures. The total fluid capacity for the engine is 8.5 quarts when including the oil filter change. It is important to note that on models equipped with an external oil cooler, additional oil may be required if the cooler is drained during service. To ensure an accurate oil level reading, owners should wait at least five minutes after refilling or turning off the engine before checking the dipstick. The oil drain plug should be torqued to 22 ft/lbs to prevent leaks while avoiding thread damage. Choosing between the 5W-40 and 0W-40 variants allows owners to optimize for local climate conditions or specific driving habits, ensuring that the thick oil film necessary for the twin turbos is maintained during high-load scenarios.
Transmission and Differential Protection
The SL600 utilizes a robust automatic transmission, specifically the 722.6 model. Proper fluid selection is vital for maintaining shift quality and protecting internal components from the extreme heat generated by the powerful engine. The total fill capacity for a complete transmission service on the 5-speed 722.6 system is 7.9 quarts. AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid stands out as a premier choice, capable of withstanding the rigors of heavy towing, elevated temperatures, and challenging terrain. It remains fluid even in sub-zero temperatures, providing reserve protection during heavy use and abuse.
For those seeking a high-performance alternative that also meets original equipment specifications, the OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers excellent wear protection and is designed to extend service intervals. Both fluids are engineered to reduce friction and heat, ensuring the longevity of the transmission’s complex hydraulic and mechanical systems.
Regarding the differential and transfer case, while specific lubricant recommendations for these components may vary based on the vehicle’s configuration, the rear differential capacity is noted as 2.5 pints. Maintaining the correct lubricant levels here is crucial for the proper operation of the rear-wheel-drive system, ensuring smooth power delivery to the road.
Cooling System and Fluid Maintenance
The cooling system in the SL600 holds a substantial 13.6 quarts of fluid, making the choice of coolant a significant investment in engine health. AMSOIL offers two distinct options to suit different maintenance philosophies. The Passenger Car & Light Truck Antifreeze & Coolant is a unique poly-organic acid (OAT) formulation, ethylene glycol-based, that comes as a 50/50 pre-mix. It provides protection up to 150,000 miles or 5 years and is free of phosphates, nitrates, nitrites, silicates, borates, and amines, making it compatible with all other antifreeze and coolant colors.
Alternatively, the Propylene Glycol Antifreeze and Engine Coolant is a concentrated formula that requires mixing with distilled or high-quality water. This option offers extended protection up to 150,000 miles or 5 years in passenger cars and up to 1,000,000 miles in heavy-duty applications. Its propylene glycol base is non-toxic and greatly surpasses standards for metallic corrosion and erosion, offering a safer and high-performance alternative for the cooling system.
Brake and Power Steering Fluids
Brake system reliability is paramount in a vehicle of this caliber. The SL600 requires a fluid meeting the MB Sheet 331.0 standard, typically DOT 4 plus. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid delivers excellent ABS and traction-control responsiveness. It maintains a stable viscosity over a wide temperature range, ensuring consistent pedal feel and stopping power whether the vehicle is stationary or moving at high speeds.
Similarly, the power steering system benefits from AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid. This fluid is formulated to reduce friction and prevent leaks by keeping seals soft. It provides strong anti-wear protection and excellent high-temperature performance, ensuring quiet operation and reduced maintenance needs for the power steering pump and rack.
About the Vehicle
The 2008 Mercedes-Benz SL600 represents the R230 generation of the SL-Class, a lineage that dates back decades as one of the world’s premier luxury roadsters. When introduced in 1995, the R230 was a technological marvel, becoming the first production car to feature the Aircap system, a retractable wind deflector that significantly reduced wind noise when the fabric convertible top was down. By the 2008 model year, the SL600 had evolved to include the legendary 5.5-liter twin-turbocharged V12 engine, codenamed 275.95 Y Turbo. This engine was a masterpiece of internal combustion engineering, delivering massive torque and a smooth, linear power delivery that defined the driving experience of a modern Grand Tourer.
Owners of the SL600 are drawn to the vehicle’s blend of exclusivity, performance, and open-air motoring. The V12 engine provides a presence that is both intimidating and refined, making the SL600 a standout in the luxury segment. The interior is typically appointed with high-quality leather, wood, and advanced electronics for its time, offering a sanctuary of comfort and technology. Whether cruising the Autobahn or enjoying a scenic drive on a Sunday morning, the SL600 is designed to offer a seamless connection between the driver and the road. Its sophisticated 5-speed automatic transmission, paired with the V12, ensures that acceleration is effortless, while the chassis geometry provides stable handling characteristics that inspire confidence.
Maintaining this iconic vehicle requires a dedication to quality components. Using premium lubricants ensures that the complex mechanical systems, from the twin turbos to the delicate hydraulic components of the convertible top, continue to perform as intended. The SL600 is not just a car; it is an engineering statement that rewards diligent care with years of reliable and exhilarating performance.
Seasonal Storage and Additional Care
For owners who utilize their SL600 seasonally or store the vehicle for extended periods, preserving the fuel and engine integrity is essential. AMSOIL Gasoline Stabilizer helps keep fuel fresh for up to 12 months, protecting against the varnish and gum buildup that can occur with ethanol-blended fuels. It fights ethanol corrosion and is ideal for seasonal equipment like classic cars and motorcycles. Additionally, AMSOIL Engine Fogging Oil is a highly effective rust preventive designed to protect internal engine components during storage or long periods of inactivity. By treating the cylinders before storage, owners can prevent rust and ensure a smooth start when the vehicle is brought back into service.
For general cleaning and preservation, the vehicle’s paint and interior benefit from products like the AMSOIL Miracle Wash Waterless Wash and Wax Spray, which requires just two easy steps to leave a fantastic shine and tough protective finish. For more intensive cleaning needs, the Heavy-Duty Degreaser effectively removes oil, tar, and grime from engine surfaces and undercarriage components. The Silicone Spray offers a dry lubricating film for surfaces that may be damaged by conventional lubricants, helping to prevent the cracking and drying of rubber components.
Performance Additives and Lubricants
To maximize the performance of the 2008 Mercedes-Benz SL600, AMSOIL P.i.® Performance Improver Gasoline Additive is a recommended addition. This fuel additive restores up to 14% horsepower by cleaning GDI fuel injectors to 100% flow rate after one tank of fuel. It improves fuel economy and reduces the need for higher-octane fuel, while also helping to prevent carbon rap and controlling pre-ignition knock. This additive is compatible with capless fuel systems, ensuring it can be used without modification to the fueling system.
For the upper cylinder area, AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor provides additional lubrication to the fuel system and upper cylinders, further protecting the engine from wear. When it comes to general maintenance tasks, AMSOIL Synthetic Multi-Purpose Grease resists thermal and oxidation degradation, offering outstanding low-temperature pumpability and excellent load-carrying performance for heavy and abusive loads. This makes it ideal for chassis points and other moving parts that require reliable lubrication in all conditions.
Undercoating and Corrosion Protection
The SL600, like many luxury vehicles, can benefit from robust undercoating to protect against the elements. AMSOIL Heavy-Duty Metal Protector contains special rust and corrosion inhibitor additives that protect against the effects of salt, moisture, and chemical corrosion. It leaves a long-lasting, protective, wax-like, amber coating that can spray into hard-to-reach places and works as an effective undercoat. For rusted components that need freeing, AMSOIL MP Metal Protector cuts through rust and frees frozen components, displacing water and stopping squeaks. This product is particularly useful for maintaining the integrity of bolts and moving parts in the suspension and chassis areas.
Detailing and Cleaning
Keeping the 2008 Mercedes-Benz SL600 looking its best involves a range of specialized cleaning products. The Power Foam® Carburetor and Induction-System Cleaner cleans deposits from ethanol and degraded fuel, removing gum and varnish to maximize horsepower and restore startability. For cleaning the glass surfaces, the Professional-strength Glass Cleaner effectively cuts through grease and grime faster than other leading cleaners with a foaming action that doesn’t run or drip. The Exterior Ceramic Spray provides an easy application that requires no cure time, shedding water rapidly and protecting against UV rays.
For the interior, the Interior Detailer – Light Lemon and Interior Detailer – Scent Free offer multi-surface use with 90-day UV protection, trapping and eliminating odors to maintain a fresh cabin environment. For more specialized cleaning, the Brake and Parts Cleaner quickly removes oil, grease, brake fluid, and other contaminants from brake parts, leaving no residue to help eliminate brake squeal and chatter. Finally, the Mudslinger® Mud and Dirt Repellent provides a protective, non-stick layer of armor against the accumulation of mud, dirt, and snow, keeping the vehicle looking pristine even after driving in adverse conditions.
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