It depends on usage and road conditions.
If they are wearing off with no abnormalities, there is nothing you can do about it except to keep the mileage low.
If abnormal tire wears are present, the suspension links etc and alignment needs to be looked into.
I used to changed my tires about once a year, running about 30 k miles. Reason was I used to drive hard.
Monday, September 24th, 2012 AT 12:45 PM