If I get the 18x7.5 42mm offset wheels that I have been lookin at for a couple of months, what tire can I fit under my car? I am currently sitting on Tokiko D-Specs and Eibach Sportlines, but I have been contiplating the air option. Can I fit 235/40's? Or would 225/40's be better? I'm also kinda confused about tire hight..... shoudl I get 35's or 40's? I am wanting my new wheels and tires to fill up the wheel wells to the outside (and yes I will be rolling my wheel well lips all the way around).
I have also been considering longer wheel studs and spacers for the rear to bring the wheels and tires out more to line up with the well lips the same that the front wheels and tires do.... But, I have NO idea how big of a spacer that I would need to accomplish this. Yes, I have heard all of the debate about wheel bearing issues and so forth. But I REALLY don't like how the back tires look like they are sunk in so far. So, pre-mature wear and tear that would be involved with useing spacers has already been takin' into consideration. My only issues are what size tires I can tuck and what spacers to get.
Thanks in advance!!

if you want to tuck, dont get spacers. read the tire faq for tire size. you need a 225/40/18 tire.

How will a 215/45/18 tire on a 18x7.5 wheel with a 42mm offset fit?

too big. 215/40/18 would be better