Tire Size

Hi guys, i was thinking about purchasing some rims for my 1997 I30, but the size of the tire is 245/40/18......i dont know where but i recall that 235 is the highest size i can go up to for that model, now is that true?? I need some feedback plz.
Thanks

It depends on the width of the rim. My 17x7s are wrapped in 225/45/17 Goodyear Eagle F1 GS-D3 rubber. I won't go any higher than that due to potential safety issues.