picking tires

[Robstah]

ok, work with me on this one. i have mille miglia mm11-2 sports, 18x8 front, 18x9 in back. these have an offset of 20 (eek), but i would love to get them working on my car. right now, the front is running 225/45/18, and the back is at 255/40/18. i am looking at getting 225/40/18 front, and 245/35/18 in the back. this is what ive heard from a few. now, i also have bilstein sport shocks/struts and eibach sportline springs coming soon, will this setup work with these tire sizes?

[Daved]

20 doesn't seem to be a right offset for an E36, I don't know how you will make them fit but 225/45/18 on 18x8 and 245/35/18 on 18x9 are just fine.

[Robstah]

i still dont fully understand the offset values. if i do install these, whats the negative side of it compared to rims at 40 offset?