How frequently motor oil should be replaced?

Replacement should be done under the operating manual for the light vehicle. In the past it was recommended to replace the lubricant after a certain mileage or time interval; nowadays the situation has changed, and some manufacturers recommend monitoring lubricants. Light vehicles manufacturers install special systems to diagnose condition of the lubricant and notifying a car holder when maintenance should be made. Under unfavorable circumstances (their list is available in the operating manual for the light vehicle) oil should be replaced more frequently.