i need bigger rims and am wonderin what is the biggest i can go b4 rolling is needed,

will be lowered 2 1/2 also if this matters

cheers

ive got 16's and have 205/45's on em and dont scrub out, im rolling 3-4 inches loer than stock too

what about 19" with 235's?

thats what im aiming for really

try this wheel calculator .put in orignal wheel size & et ,then the size youwant to run.
http://www.1010tires.com/WheelOffsetCalculator.asp 
Wheel Offset Calculator

dont forget legally you can only go 2inches bigger than stock, any bigger and i think you need an engineers certificate or something.

diameter mightn't matter as much as width...my 225's with 35 offset fit with 10mm clear both sides...235 might be the max