Can topping the oil up be used instead of changing it?
No. When carrying out its lubrication function, the oil is subjected to a lot of a ggression. Particularly, it becomes full of impurities, combustion and oxidation residues. The oil becomes degraded and less effective. When its working lifetime is over, its qualities have cchanged and the protection of the engine elements is no longer guaranteed. So, oil needs to be replaced regularly. Topping up does not regenerate the used oil. The oil level should be checked regularly (every 1000 km.), especially before a long journey.
