So last year I went from (after 1 year on them) Hankook Ventus V12 (Max Performance) to a Bridgestone RE11 (Extreme Performance) last year and I was probably .75 to 1 second closer (over a 60 second course) to identical spec cars and more consistent (because I did not over drive them as much trying to catch up)
You can look at historical times in A class for me to see the difference. I started last year on the new tire (the only change).
B