Belle Tire replaced all four of my Contiseals at 8,600 miles. The left front tire had started to bounce like a basket ball. When they took it off the rim , there was a smooth shiney spot about the size of my fist on the inside. The sealer had started to ball up. Tire guy told me it was a known problem. I had them order the Conti Touring tires , I didn't want anymore Contiseals. All I paid was the tax on the tires. The touring tires seem to handle much better, and there is no vibration or bouncing. I found out that how the tire shop deals with Continental is what decides if you get new tires or not.