For the 6.3L V8 engine, AMSOIL offers two distinct viscosity grades depending on your climate and driving habits. Both options provide superior protection against high-temperature breakdown and sludge formation compared to conventional oils.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – An optimal choice for extreme temperature protection, this fluid ensures rapid oil flow during cold starts while maintaining stability under the high heat of a performance V8 engine. It is designed specifically for the unique demands of European gasoline, diesel, and hybrid vehicles.
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – Ideal for warmer climates or moderate driving conditions, this premium synthetic oil features a precise blend of base oils and additives to protect against wear and deposit formation while meeting the strict requirements of your engine manufacturer.
The engine oil capacity for the 6.3L DOHC E engine is approximately 9.3 quarts when including the filter. Owners with vehicles equipped with an external oil cooler should note that additional oil may be required if the cooler is drained during service. Always allow the engine to sit for five minutes after refilling or shutting down to ensure an accurate reading on the dipstick. Proper oil selection is critical, but it is equally important to maintain the cooling and lubrication systems of the transmission, differential, and braking components.
Proper lubrication is the backbone of reliability for the CLS63 AMG. The transmission, specifically the 7-speed 722.9 unit found in this model, requires a fluid that can withstand the rigors of high-torque shifts and elevated operating temperatures. The factory fill capacity for a total transmission fluid change is 9.3 quarts. AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid and OE Fuel-Efficient synthetic automatic transmission fluids are engineered to remain fluid in sub-zero temperatures and protect against wear during heavy towing or spirited driving. These fluids provide a stable viscosity that resists thinning, ensuring smooth shifts and extending the life of the transmission clutches.
Complete Fluid Maintenance Guide
Maintaining the cooling system is essential for the longevity of this high-output engine. The vehicle’s Passenger Car & Light Truck Antifreeze & Coolant capacity is 12.5 quarts. This unique 50/50 pre-mix formulation offers protection up to 150,000 miles or five years. It is phosphate-, nitrate-, and silicate-free, which ensures compatibility with the aluminum and rubber components used in modern Mercedes cooling systems. For those who prefer to mix their own, AMSOIL Propylene Glycol Antifreeze and Engine Coolant provides concentrated protection that significantly surpasses OEM standards for corrosion and erosion resistance.
The braking system on a performance vehicle like the CLS63 AMG requires a fluid with a high boiling point to prevent vapor lock under heavy braking. The recommended fluid is DOT 4 Plus, which aligns with Mercedes-Benz Sheet 331.0 specifications. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid offers excellent responsiveness for ABS and traction control systems. It maintains stable viscosity across a wide temperature range, ensuring consistent pedal feel and safe stopping power in both freezing conditions and under track usage.
Power steering systems benefit from fluids that prevent seal leaks and reduce friction. The CLS63 AMG utilizes a power steering system that requires specific fluid compatibility. AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is formulated to keep seals soft, preventing hardening and subsequent leaks. It resists heat degradation, ensuring long fluid life and providing anti-wear protection to keep the steering operation quiet and responsive.
Vehicle Background
The 2009 Mercedes-Benz CLS63 AMG represents a unique segment in the automotive world, blending the sleek, coupe-like styling of the CLS-Class with the raw power of the AMG performance division. Introduced as a four-door “sportback,” the CLS series challenged the traditional sedan and coupe definitions, offering a low-slung, aerodynamic profile that turned heads wherever it went. The CLS63 AMG variant, in particular, became a legend in its own right, offering an unprecedented combination of daily usability and supercar performance.
Under the hood lies the formidable M156 6.3-liter naturally aspirated V8 engine. This pushrod-derived powerplant was renowned for its linear power delivery and distinctive exhaust note. It produced an immense amount of torque, making the car feel surprisingly agile despite its weight. The CLS63 AMG was a favorite among enthusiasts who wanted a grand tourer that could handle daily commutes while still providing an adrenaline-fueled driving experience on backroads or the track. The interior combined luxury with sportiness, featuring supportive seats and a cockpit designed for the driver. Built on the W219 platform, the vehicle was a testament to Mercedes-Benz’s ability to engineer complex, high-performance machines that could be driven with confidence in any condition.
For owners looking to preserve this performance legacy, AMSOIL offers a range of additional protective products. The AMSOIL P.i.® Performance Improver gasoline additive can restore up to 14% horsepower by cleaning injectors and fuel systems, helping the engine breathe better and run more efficiently. For storage periods, AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months, preventing varnish buildup, while Engine Fogging Oil protects internal components from rust during extended inactivity. Exterior care is also important for maintaining the vehicle’s appearance, with options like AMSOIL High-Foam Car Shampoo and Exterior Ceramic Spray providing superior cleaning and protection against UV rays. Whether you are performing a full fluid service or simply topping up brake fluid, choosing the right AMSOIL product ensures your 2009 CLS63 AMG continues to perform as the premium German machine it was designed to be.