i have always only insured my car for 4000 miles, but we are trying to even the wear on our cars - not that either of us do that much, so i phoned and asked for it to be raised to 7000, but they said that it did not affect the premium at all and that our other car has no set mileage limit at all. I guess that in the grand scheme of things, it doesn't affect it that much, but I am sure that if you went over your recorded limit and were in an accident, they would not cover you.