i have a 2000 civic si and im about to lower it and get wheels. My question is what offset will fit, there is like a +33 and a +42.

 

well it depends on how wide you are gonna go. my si is hammered and it is still on stock rims with 20/15/50 which is wider and lower profile than stock size. mine rub on the drivers side so i also have to be cautious when getting new rims. the stock offset is 45 so if you go 42 or 40 it will bring them out towards the body a little (on 6" wide like stock rims anyways). most aftermarket rims are 6.5 and up. so dont forget about that either. maybe the links can help. http://toy4two.home.mindspring.com/offset.html http://www.miata.net/garage/tirecalc.html

 

How wide is the wheel? How low are you going to go?
You can fit both +42 and +33 most likely, but the with the +33 you're probably going to experience some rubbing on the fender.