For the record, the "bulge" you hear about so much still is purely in the eye of the beholder. I personally think it looks better to have a narrower wheel than a wider one on Broncos in most situations. Not all of course and 10" wheels abound, but my go-to is an 8.
But again, that's personal preference.
The bulge is purely a look comparing the relative roundness of the sidewall. It's not actually bulging out any wider on the narrower wheel. It's just the sidewall is further outboard of the bead that give it that look.
In fact it should be approx. the same sidewall width on either wheel on a 15" due to extensive sidewall flex. Just looks bulging because the bead is tucked in tighter.
Might be different on different diameter wheels with shorter profile tires, but haven't physically tested those. Just 15's and 16's for the most part.
Paul
