How about tire pressure - is it the same L to R? try changing it, probably lower if you are experiencing these problems - just a thought! Also, you might want to have a rep from the company that mfg's the tires look at it, as I can't imagine the tires making THAT much difference! What did the tire dealer say? However, my car has done all of these things since I got it (with 8500 miles on it), and I just chalked it up to the stiff suspension. It's been aligned three times (now has 17,900 miles on it) to try to correct a left pull (to no avail!). Of course I'm in the fast lane 98.9% of the time, and it's usually crowned right - hence the left pull? I used to have a TR6 that would follow the ruts in the road too - I got used to it after a while.