ok so i think i decided to get some cobra r's soon, and i was wondering what size tire i need to keep the same diameter so i wont have to get a new speedo gear or have any reprogramming done. i want 275's in the back if possible. im planninng on 17"x9" cobra rs by the way. thanks.
Shouldn't mess up your speedo calibration. It might read 1mph slower with the 275/50/17s. I'd go with 255/40/17 all around. If you did that, it'd probably read 2-3 mph higher than stock.