Oil change interval: by kilometers or by months?
Short answer: Both. Owner's manuals give a distance and a time limit, and you change the oil at whichever comes first. Oil ages even when the car sits, so a car driven 3,000 km a year still needs a change at the time limit.
Typical intervals
- Many modern cars with synthetic oil: about 10,000–15,000 km (6,000–10,000 miles) or 12 months.
- Older engines or conventional oil: often 5,000–7,500 km (3,000–5,000 miles) or 6 months.
Your manual is the authority; these ranges are only a starting point.
When to use the shorter "severe" schedule
Short trips under 10 km, lots of idling or stop-and-go traffic, towing, dusty roads and very hot or cold climates count as severe use in most manuals. Many daily city drivers fall into this group.
Other items that run on the same rule
Tire rotation, air and cabin filters, brake fluid and coolant also have distance and time limits. Inspection and insurance renewal are time only.
How to track both limits
Write down the odometer and date of each change and work out the next due point for each limit. In Odonote, set an item's interval in km, months, or both; the home screen shows what is next and how many km or days are left, and the reminder fires for whichever limit is reached first.