Tire Tread/belt problems of the 2002 Mazda Protege 5

The contact owns a 2002 Mazda Protege 5. The vehicle has kumho (p195/55r15) tires. While at the dealer for regularly scheduled maintenance, the contact was informed that she needed a new tire. The dealer noticed a split and wear on the inside tread of the tire. She does not know if the other tires have the same failure as well. The purchase date was unknown. The tire failure mileage was 19,022. The vehicle current and failure mileages were 47,290.