All fastbacks came with 205/60-15 up front and 215/60-15's in the rear. The '86-'87 fastbacks had 15x7 wheels on all four corners and the '88 Formula & GT had 15x6 up front and 15x7 in the rear.
Non-fastback V-6 Fieros ('85 GT & '85-'87 SE) had 215/60-14 as the top end tire.......some had 195/70-14's, I believe.
Overall tite diameter for a 205/60-15 tire is about 24.7"; 215/60-15 is about 25.2". These numbers vary by manufacturer though.....depends a lot on tire construction/tread design.
[This message has been edited by mrfiero (edited 08-21-2009).]
