195/50/15 is the biggest you can go on one of them... a 205/50/15 will ahve a to bigger rolling diameter from the standard 165/73/13 size and are also alot more expencive and havent got as much of a choise from the 195's a 205/55/15 is the correct size for ra series celicas and are way to big for a corolla... they are actually elligal in most stated for a corolla... 195/50/15 is the way to go they are very close and the legal size for the corolla you wont wanna go a higher diameter then that