The 2021 Mercedes-Benz C300, equipped with the 2.0-liter 4-cylinder turbocharged engine (code 264.920), demands a level of fluid precision that synthetic lubricants deliver better than ever before. This sophisticated German sedan places significant stress on its internal components, particularly under load or in extreme temperatures. Proper maintenance with the correct viscosity and additive package is essential to ensure the turbocharger spins freely, the engine remains clean, and the transmission shifts smoothly for years to come. Neglecting these specific fluid requirements can lead to premature wear, reduced fuel economy, and costly repairs that are easily avoided with the right AMSOIL products.
Recommended AMSOIL Products
For the 2021 Mercedes-Benz C300, maintaining peak performance requires selecting the appropriate synthetic European oil. The engine calls for specific viscosities like 0W-20, 0W-30, or 0W-40 depending on the temperature, with 5W-30 and 5W-40 also suitable for conditions above -25°C. The engine oil capacity is approximately 7 quarts with a filter change, though it drops to 6.3 quarts without a filter refill. Additionally, the cooling system requires 9.1 quarts, and the transmission fluid needs to be replaced with a product formulated for automatic transmissions.
- AMSOIL 5W-30 LS 100% Synthetic European Motor Oil – Designed specifically for the unique demands of European gasoline, diesel, and hybrid vehicles, featuring a precise blend of synthetic base oils and premium additives to protect the turbocharged engine.
- AMSOIL 5W-40 MS 100% Synthetic European Motor Oil – An excellent alternative viscosity option that offers superior protection against high temperatures and engine wear, engineered to meet the rigorous standards of modern European engineering.
- AMSOIL 0W-20 LS 100% Synthetic European Motor Oil – The ideal low-viscosity option for maximizing fuel economy and ensuring fast cold-start protection, specifically formulated for the strict tolerances found in 2021 Mercedes-Benz engines.
Beyond the engine, the cooling system of your C300 requires a AMSOIL Passenger Car & Light Truck Antifreeze & Coolant capable of protecting against corrosion and maintaining optimal operating temperatures. The 2.0L engine holds 9.1 quarts of AMSOIL Propylene Glycol Antifreeze and Engine Coolant, which can be filled using either a pre-mix or a concentrated formula. Furthermore, the automatic transmission and brake systems benefit significantly from AMSOIL’s specialized fluids. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid must meet DOT 3 and DOT 4 standards, often specified as DOT 4 Plus for Mercedes models, to ensure responsive pedal feel and ABS reliability. For the transmission, AMSOIL offers fuel-efficient synthetic options that reduce friction and protect against sludge, ensuring smooth power delivery from the turbo engine to the wheels.
Complete Lubrication Guide
Engine Oil and Filtration
The heart of the C300 is its 2.0L turbocharged engine. This unit generates significant heat, which requires oil that can withstand thermal breakdown. The recommended oil change interval for this engine is 7 quarts when replacing the filter, or 6.3 quarts for a top-off scenario without a filter. Always torque the drain plug to 30 ft/lbs and replace the seal to prevent leaks. While the source indicates no specific oil filter recommendations are available in the database for this model, using a high-quality AMSOIL oil filter is often standard practice when performing a complete service to ensure maximum flow and filtration efficiency.
The engine accepts a range of viscosities. For year-round protection, the 0W-20 AMSOIL LS is often preferred for its ability to flow instantly on startup. For slightly warmer climates or to maximize stability under heavy loads, 5W-30 LS or 5W-40 MS are excellent choices. All three oils are 100% synthetic and European-formulated, meaning they are additive-rich to handle the soot and carbon byproducts common in turbocharged direct-injection engines.
Coolant Protection
The cooling system is critical for the longevity of the turbocharger and engine block. With a capacity of 9.1 quarts, the system is large enough to require a substantial volume of coolant. AMSOIL offers two primary options for this vehicle. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a pre-mixed, ethylene glycol formulation that protects up to 150,000 miles or 5 years. It is free of phosphates, silicates, and borates, which makes it safe for all cooling system metals, gaskets, and hoses. Alternatively, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant is a concentrated formula that requires mixing with distilled water, offering extended protection and excellent freeze-thaw performance.
Automatic Transmission Fluid
Automatic transmissions in the C300 operate under high stress. Using the wrong fluid can lead to shuddering, delayed shifts, and internal wear. The recommended fluids for the C300’s automatic transmission are the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid and the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid. Both are engineered to withstand the rigors of towing and elevated temperatures while remaining fluid in sub-zero conditions. The Signature Series offers extended life and reserve protection, while the OE series provides excellent wear protection and fuel efficiency, both meeting or exceeding OEM requirements.
Brake Fluid and Other Fluids
Brake safety cannot be compromised. The C300 requires a DOT 4 compatible fluid. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is a top-tier choice that provides excellent responsiveness for ABS and traction control systems. It maintains stable viscosity over a wide temperature range, ensuring consistent pedal feel and preventing moisture absorption that can lead to brake fade. Note that the transfer case lubricant for this specific vehicle configuration is listed as unknown or manufacturer-specific, so check the service manual for specific fill amounts, which may be around 1.5 pints if equipped.
About the Vehicle
The 2021 Mercedes-Benz C300 represents a pinnacle of compact luxury sedan engineering, blending sporty performance with refined comfort. Built on the Mercedes-Benz MRA platform, which supports rear-wheel and all-wheel-drive configurations, the C300 is widely regarded as one of the best-driving sedans in its class. The model year marks the continued evolution of the C-Class, known for its agile handling, intuitive technology, and high-quality interior materials that set the standard for German automotive design.
Under the hood, the 2021 C300 is powered by the M264 engine, a 2.0-liter four-cylinder inline turbocharger. This unit produces a robust 255 horsepower and 295 lb-ft of torque, paired with a 9-speed automatic transmission that delivers seamless power delivery. The turbocharged setup requires precise lubrication to manage the high heat and rotational speeds of the turbocharger, making the use of high-quality synthetic oil critical. The vehicle’s chassis and suspension tuning offer a driving character that is both compliant enough for daily commutes and sporty enough for spirited weekend drives.
Owners often appreciate the C300 for its perfect balance of efficiency and power. The 2.0L engine delivers fuel economy that rivals larger V6 competitors without sacrificing acceleration. However, this high-revving turbo engine is not without its specific maintenance needs. Synthetic lubricants are the best solution to address common concerns associated with turbocharged European engines, such as carbon buildup on intake valves and oil consumption in high-mileage units.
While the C300 is a robust machine, owners should be aware of a few potential issues that synthetic AMSOIL fluids can help mitigate. First, turbocharged engines can develop turbo lag or sluggishness if carbon accumulates on the intake valves and throttle body; using a fuel additive like AMSOIL P.i.® Performance Improver can help restore flow and performance. Second, some owners have reported oil consumption issues in certain model years, which can be exacerbated by using conventional oils; a high-quality synthetic European formula like AMSOIL LS is designed to resist volatilization and reduce consumption. Third, the cooling systems on these vehicles are sensitive to corrosion over time, which can lead to expensive radiator or thermostat failures; using a phosphate-free, silicate-free coolant ensures long-term protection for aluminum components. Finally, automatic transmission shudder or hesitation can occur if the fluid degrades or becomes contaminated; AMSOIL synthetic transmission fluids provide a stable friction profile that prevents these harsh shifts and extends the life of the clutch packs and bands within the transmission.
By understanding the specific needs of the 2021 Mercedes-Benz C300 and utilizing the correct AMSOIL products, owners can ensure their vehicle remains reliable, efficient, and enjoyable to drive for the long haul. Whether you are navigating city streets or cruising on the highway, the right lubricants provide the peace of mind that your investment is fully protected.