What's the backspacing on the 18s? I want to swap my Duster from 14/15" Rallys to 17s, but am terrified of spending a pile of money and finding out that the wheels do not fit.
My 18x9’s have a +35mm offset, so that’s a 6.38” backspace. The DoctorDiff 13” brake kit I run adds about 5mm, so effective backspace compared to a 73+ mopar disk is about 6.2”.
With 17’s though you can’t go that deep, the outer tie rod end will hit the lip of the rim on a lot of 17” wheels if you go past about 5.7”. It depends on the design of the wheel, there are some that can do more but with 17” I wouldn’t go past 5.7”, which also means a 255 is about the widest you can safely go without significant fender mods
