Since the application areas of adjacent SAE classes coincide, short-term temperature fluctuations should not be taken into account. It is permissible to mix oils of different viscosity classes if the topping up is done once and the external temperature no longer corresponds to the viscosity class of the oil in the engine.
For C-class gasoline engines, API specifications SF and SG motor oils are suitable, and for diesel engines – API-CD.
European oil manufacturers additionally set the CCMC specification, which takes into account European engine manufacturing technology and is becoming increasingly important. Oils for gasoline engines in the CCMC are designated from class G1 to G5.
For petrol engines, Mercedes prescribes CCMC-G4 as the minimum standard for all-season oils; CCMS-G5 is a low viscosity, easy-flowing oil.
These standards roughly correspond to the API specification SG, additionally meeting European requirements.
For diesel engines of class C, motor oils of API classification CE and CF-4 are suitable, and for gasoline engines – API-SF and SG.
Oils for gasoline engines in the CCMS are designated from class G1 to G5. Diesel oils for passenger cars are contained in the CCMS specification - D4, D5 and the high-quality specification CCMS-PD2, CCMS-D4 approximately corresponds to API-CE; CCMC-D5 is similar to API-CF-4.
For normal operation of the car, it is sufficient to use CCMS-D4 motor oil. High-quality oils of classes D5 and PD4 can also be used at any time. It is fundamentally necessary to use standard CCMS oil of API CE and CF-4 specifications.
In each individual case, follow the principle of using engine oil recommended by Mercedes-Benz (marked on the oil canister).