What does oil do inside an engine?
Many metal parts move rapidly when an engine runs. Oil forms a film between contact surfaces to reduce direct friction, and carries some heat and fine contaminants back to the sump and filter.
Prolonged heat, repeated short trips and starts, or heavy loads can age oil faster.
Topping up is not an oil change
Topping up a low oil level only restores the level to the normal range. Contaminants remain in the old oil, and the filter is still used.
- Change the oil and filter at the manual's intervals
- Check the dipstick or electronic oil level regularly
- If the level keeps dropping, investigate leaks or oil consumption
How often should oil be changed?
No single mileage suits every vehicle. Start with the manual's distance or time limit, whichever comes first. Frequent short trips, idling in traffic, heavy loads or hot conditions may require the manual's severe-service schedule.
Keep in mind
Use the manufacturer's schedule first, not oil colour or a workshop's general mileage rule.