I'm considering picking up a set of Halibrand Cobra III Mid-Lip wheels, either in 18" or 20". I know the correct bolt pattern is 5 X 114.3, but what is the correct offset for the '06 GT for both the 18 and for the 20?

Would the offset put the lip of the rim even with the fender lip, or would the wheel be set further in (about where the stock Fanblades sit?)

Also, if I'm going to go with the stock BFG 18" tires (235s) from my Fanblades, would there be any issues mounting them on an 18 X 9 rim?

 

i really would not put a 235 on a 9 " wheels...might look silly..With wheels like those i would strongly urge to upgrade your tires

alot of wheel and not enough tire..minimum i would put a 255 but it can easily support a 275

but you could do it if you have no choice..

The stock offset is 45 MM for the 17 x 8 wheel......

your fanblades are 18 x 8.5 with a 50 MM offset...