I had a car kind of like that. Started keeping track of miles.
That's what we try to do, but it doesn't always work out... though on at least 1 of those occasions, I simply wasn't paying attention to it at all. On another occasion I was planning to fill up at the next stop anyway, but didn't quite make it. Then this time we had no idea it was so low, but that's kinda our fault too, since we hadn't filled it all the way up the day before.