[BYprodriver]

Originally Posted by bwillia080261

I had the same problem. I put on brand new tires and watched them dynamic balance them. The rims were perfectly straight and I still had some wobble, particularly on cold tires. It got better when the tires warmed up. This makes me think a lot of high performance tires have some Nylon cords in them. Also I put a 60 lb. bag of sand in the front boot and believe it or not that helped a LOT. Unconventional I know but it also seems to ride and handle better with the weight.

Every DOT approved tire I have ever looked at lists material & number of belts & plies in tread & sidewalls. Early speed rated Hi- perf radial tires like the Pirelli P7 use a nylon "cap" belt to minimize tire deformation at high speeds. Nylon shrinks when heated & flat spots easily while cold. Michelin Pilot Super Sports don't have nylon belts. One of the many pluses of using premium tires. Weight is a great dampener & Porsches are very sensitive to imbalances. I often notice a ride quality difference between a full tank & low tank.