so like i said before, i just got 17x8 rims...
so i went to couple shops looking for wheels, they said max wheel i can manage on my WRX w/ the rims were 225/45/17...
However, i see people on here using 235's...240/40...
so i was just wondering if the shops were just playing it safe and saying to stick with the 225...or they just don't know...

It depends on your suspension setup though. Go check the suspension forums, you can probably find someone with the same suspension setup as you and then u'll know what tires you can fit.

A lot of shops go by the "book" and don't actually know what fits. The onyl way you find out is by trying. I know guys with 255's on their WRX sedans. 225/45 is a very safe size. 235 is not a problem and 245/40 will be tight depending on suspension and wheel offset/width.