i had 225/50/16 tires on my mr2 and swapped those tires onto my alltrac rims a long time ago without checking the ratio.
my acceleration was slower. when i put my stock alltrac rims back on, the car feelt lighter and more nimble. havng oversized tires will slow you down!
anyways, 225 will fit on a 6.5" rim. being if you get 225/45/16 tires, the sidewall will not stick that much out. i tried 50 series which was a mistake but it was free. if i were to buy a new set of tires. it would be 225/45/17. but, i had sold the set of GTS rims and bought some 17s.
i have 215/40/17 on 17x7 now but after seeing some 235/40/17 on some 17x8s, i want 235/40/17s...