A4 B8.5 Hub size & spacers
 

I have a 2014 A4 B8.5 and recently found wheels I like (Audi factory 18") but the new wheels have 57.1mm hub center bore and my A4 apparently is 66.6mm CB. I bought a set of 66.6mm CB spacers without a hub lip. They are 10mm deep which will fully cover the existing hub lip. So, when I mount my new wheels, they will not be supported by a hub lip at all, only the 5 lug bolts (yes I did get 40mm deep bolts to account for the spacers. A lot of wheels out there are mounted with lugs only. Any advice on whether or not this is a safe and functional setup.