because with that much tread worn off they were taken off for a reason. When the sport tires get about half worn they can make terrible road noise and still appear to have plenty of tread left. You won't be able to tell by the pictures but any kind of scalloping on the inside or outside of the tread will make noise. You should be able to find some reasonably priced tires on Tirerack.com that would make you a lot happier in the long run.

Paul