[trumph]

I researched this issue extensively as my problem was excessive wear on the inner shoulder of every tire (25K miles). I looked at a comparable tire size (195/60R14) to maintain the same (or almost the same) tire diameter to maintain the correct speedometer/odometer reading. After researching several manufacturers, I thought I had decided on the specific tire for my needs (safety, longevity, performance, etc.). Obviously, this excessive wear has been occuring for some time (and reported to the Toyota dealer in warranty several times), and in my discussions with Bridgestone Technical Support, only alignment could be causing this problem. I've had disagreements (understatement) with the dealer and so I called Toyota Customer Relations. They indicated Toyota would not support any decision to replace the tires with any tire other than the high load rated tire designed for the vehicle (Bridgestone RE92, Dunlop SP10). The dealer indicated a different tire size would affect the alignment and would not guarantee the results. After some consideration, I chose the Dunlop SP10 (made only in the size for the 1st gen. Prius). I will not make purchase from the dealer and got them through special order at SAM's.

When I purchased my vehicle, I asked if a full size spare would fit in the wheelwell and was told no. After I recieved the vehicle, I placed a wheel in the wheelwell and determined that it would fit if the tools were relocated outside the wheelwell and small modifications to the foam pads in the wheelwell. So when I replaced tires, I purchased 5 tires and I plan a 5 tire rotation.

Lastly, I believe the tire pressure must be maintained at 40PSI minimum. These tires are rated 50PSI maximum, so I keep 42PSI in front and 40PSI in rear. After only a few hundred miles, it is apparent that this higher pressure is effective in limiting the excessive shoulder wear.

Just my 2 centavos. YMMV