Offset question

[KOG_GSX]

Ok, I'm looking at these 18x7.5 adr's JUST to race with. The size of the rim is 18x7.5 with a +42mm offset and come with 225/40/18 tires. Since I have a widebody, I had to add spacers to the car, so here's the questions... I want to run wider tires with these rims, and they only come with a +42mm offset or a +48mm offset, so if I get the +48mm offset, can I get some wider tires... how does that work?

 

[wret]

Since you are using spacers, and you haven't told us how thick, we cannot accurately answer the question. Also, what other suspension or bodywork changes have been made?

 

[KOG_GSX]

Spacers - 2" front, 3" rear. JIC coilover suspension. Stoptech kit up front so I would need them to clear those. So would getting the +48mm bring the face of the rim forward or backward?

 

[KOG_GSX]

Is it possible to fit 235's on these 18x7.5's with a +42mm offset?

 

[KOG_GSX]

Ok, thanks for the help guys. Oh, and just so I can understand the logic behind this, say I were to put a 235 tire on it, what would be the result, not a good enough fitment between the tire and rim?

 

[wret]

The only reason we obsess about offset is that there is a limited amount of space between the suspension components and the fender, especially at the rear. +40mm offset is ideal and a couple of millimeters here or there can make the difference between a great performing setup and terminal rub. If you are spacing your wheel out, you do not need to be concerned with suspension rub and I can only assume that you have a way to prevent the fenders from trying to occupy the same space as your tires.

When mounting a tire on a wheel that is narrower than manufacturer's recommendations, handling performance can be compromised. I get the feeling that handling is not the primary objective though.

 

[KOG_GSX]

It is. I would like to take my car to the drag occassionally, and deff do some road race courses, not sure about competing, but deff would like to go to road courses and really push my car to her limits. That's why I'd like to run 235/40/18's as opposed to 225, but will it be okay on an 18x7.5 wheel?