Gas engine
Note: Use engine oils of SAE classes 5W20 and 5W30 only in areas with very low temperatures. For a turbo engine, table K-1602 applies, except for SAE 30 season oil.
Diesel engine
Since the application ranges of adjacent SAE classes overlap, short-term temperature fluctuations can be disregarded. It is allowed to mix oils of different viscosity classes if oil topping up is necessary, and the oil poured into the engine does not correspond to the ambient temperature in its viscosity class.
Oil additives - no matter what kind - should not be added to either fuel or engine oil.