i am about to purchase a set of 18x9 and 18x10 rims....right now i am running with the stock 225/45/18 and 245/45/18 tires on a touring roadster.....my question is if it will be okay to transfer these tires over to the new rims or do i need different sized tires?

 

I would definetly put a larger tires on. Maybe a 245/40/18 and a 275/35-40/18. Not too familiar with 18" tire sizes, but I know the stockers will be too small

 

def change the tire sizes.i have 18-8.5 and 18-10 and i run 245/40/18 frt and 275/40/18 rear.your stretching the tires to much for the wider wheels.