There is no guaranteed safe number of miles beyond an oil-change interval. Arrange the overdue service and check the oil level and warning messages before deciding whether the car should be driven.
Separate an overdue reminder from a fault
An overdue service reminder is a scheduling problem; low oil pressure, overheating, a major leak or abnormal engine noise can be an immediate mechanical risk. Stop safely and switch off for an oil-pressure warning rather than trying to reach a service shop.
Collect the information a workshop needs
Note how far and how long the service is overdue, the previous oil specification, recent driving and any top-ups. Ask the workshop for advice based on those facts. A low-mileage year of short trips is not equivalent to the same distance covered on long warm journeys.
Do not manufacture a new interval
Topping up, switching to synthetic oil or clearing the dashboard reminder does not undo overdue maintenance. If history is uncertain, have it assessed and start a dated service record. Do not rely on an internet claim that every engine tolerates another fixed 500 or 1,000 miles.
