Originally Posted by daisuke149

widening the rear 2 inches and adding a 25mm spoiler essentially gives you a 19x12 + 30 wheel.

I run a 20x12 + 20 and it pokes out about 8mm. but i also run a 325 tire and have very little camber and am not lowered.

If you lower your car and run camber around -2 ish and a 325 tire you may consider a 30mm spacer or even 35. But the good thing about spacers is that they are relatively cheaper. So do the setup, get the tire you want and then when you put it on you can see how big you want to go beyond 25mm spacer.