Does my car estimate this on time alone or does it look at how the car has been used too? For example shorter intervals if it's been tracked a lots longer if it's done gentle motorway runs.
No, it won't do as you describe unless it detects an actual fault - then you may get the service light early. It works off time or miles, whichever comes up the first. You should generally service it more often anyway if you're tracking it a lot.
