Can different types of oil be mixed?

Oils of all manufacturers can be safely mixed with each other, as can summer oil with all-season oil. This mixing compatibility without harmful effects is a basic requirement of international standards for oils. However, the specific properties of a given oil may change slightly when mixed with another engine oil, because each oil has its own combination of additives. However, such mixing does not have a threatening effect on the lubricating action.

Those who follow the oil specifications listed by Audi need not worry that an unsuitable mixture will damage the engine.