Here are pics of my previous 19x9.5 ET33 & 19x10.5 ET45 VMR’s with 265/295/30 Trofeo’s. Lowered 12mm front, 17mm rear. -3.0 & -2.0 camber front/rear:
https://f87.bimmerpost.com/forums/sh...&postcount=379
As you can see, plenty of room on the outside and there was plenty of clearance on the inside bc I’m running Dinan HAS.
A 305/35/18 is 5mm taller and wider towards the fender. Add in that I’m going to ET40 from ET45, and I’m now 10mm further outboard and 5mm taller than what you see in the pic.
I now run -2.1 camber in the rear (which gives ~1mm more clearance vs -2.0), but I didn’t want to chance my luck adding another 3-4mm outboard with the 18x11. My gut tells me you’ll be fine after trimming tabs and a little fender roll, but I didn’t want to do the fender roll so I played it safer.
All this said, when we're playing the mm game, alignment accuracy and movement (if you don't have lockout bolts/nuts) and differences in tire construction even in the same size will all have fitment & interference impacts that will overshadow the minimal clearances we're talking about. Something about metal rubbing into rubber at high speed also made me want to play it safer with the 18x10.5".
