On my -7A, I got 499 landings out the original Van's tires over 727 hrs. during a 6 1/2 year period. I kept them inflated to 45 psi, rotated them once and made about 10 landings on grass with the rest on good, hard surface, runways. They still had 1/32" - 1/16" of tread left.
I haven't done more than a half dozen touch and goes. 99% of my flying is long distance (2 - 3 hr.) cross countries.
I changed to Desser Monster retreads and am anxious to see how they wear.
I changed out the nose wheel tire 2 1/2 years ago because of a sidewall cut. There was still plenty of tread remaining. I keep it at 35 psi.
Mike