I just moved from a 987.1 to a 981 Cayman S. My auto-x tire set on the 987.1 were 18" wheels with 235/40R18 and 265/40R18s tires. My new 981 came with 19" wheels and the tires are 235/40R19 and 265/40R19. The overall diameter difference between the two wheel sets is one inch. If I mount RE71s in 235/45R18 and 265/45R18 to the 18" wheels, the diameter difference is reduced to .1. I don't mind a little more sidewall on my auto-x tires, and I know Porsche recommends this size for winter tires. Just curious if the performance will suffer with this set up.
Thanks in advance.