Thank you, exactly the information I was loooking for.
I have a set of Good Year Eagle Revspec on the car (might be original) and they wear on both edges (inside and outside), more on the inside, so I figured a wheel alignment would be in order (55K miles, no accident). However, after some research, I found that this tire wears on the edges even when there is some thread left in the middle (tire pressure is to manufacturer`s spec most of the time ). So given that the alignment (and most everything else ) is rather expensive here (Japan) I will buy a set of new tires, monitor the threadwear and see if the car really needs an alignment.

Alex