2014 Subaru Forester Tires Problems

Two tires on our car developed the same problem two weeks apart: a large bulge in the sidewall near the rim. On 10/5/21 we noticed a bulge on the rear driver’s side tire which looked like a tennis ball was emerging. We took it to our mechanic here in Ohio. He said not to drive on it and replaced the tire. It had less than 13,000 miles on it and I thought it should be covered under warranty. We were told the bulge was due to “road hazard” and so wasn’t covered. They said a chuckhole could do this. We have no recollection of anything like that. And a chuckhole would usually affect the front tire, not the rear. Moreover, the mechanic looked at the rim and said it was not dented. So they suggested I contact Cooper Tire. I paid for the tire and called Cooper. They had me bring the tire to a different shop for evaluation, recommending a Conrad’s Tire nearby. I took it there and the mechanic called Cooper and told them he saw no evidence of road hazard. Cooper then asked me to send the tire to them. Two weeks later we were in Connecticut and heard a low sound from the tires. We took the car to a local shop 10/19/21 where the mechanic showed us a bulge in the sidewall of the front passenger's side tire near the rim that looked exactly the same as the prior defect albeit somewhat smaller, maybe golf ball size. He said it was dangerous to drive on it and he replaced it. I have a photograph of the second tire but unfortunately not the first. Except for the noise the second tire made, there was no noise or warning light or other symptom to alert us to either problem. I sent both tires to Cooper by UPS on their dime three weeks ago and have not heard back. Tire size: M&S 225/60R17 Both tires are DOT U941 1CW 4619 C07R Both were purchased 5/19/20 Thank you in advance for looking into this. I still have two tires on our car purchased at the same time as the two that failed. If there is truly a defect ,either could fail suddenly at any time. Thank you.

YOKOHAMA G-91 TIRES- ON A SUBRAU FORRESTER 225-60-17 WITH LESS THAN 30K MILES THE TIRES WERE BALDING. ROTATIONS WERE DOWN BETWEEN 6000 AND 7000 MILES- LIKE CLOCKWORK. I WROTE YOKOHAMA. I HAVE NOT RECEIVED A RESPONSE. I HAVE SPOKEN WITH OTHER OWNERS, (SUBRAU USING G91) AND THEY HAVE NOTICED THIS PROBLEM,TOO. I HAVE PURCHASED ANOTHER BRAND OF TIRE AS THESE ARE DANGEROUS-