[Biturbos4] rear suspension clearance

[Rich Shiba]

Heya, I think i'm having some clearance issues running 235/40-18's.
I'm sure it varies with tire manufacturer/shape and wheel offset.  i'm
running 18" BBS CH (recommended offset for the S4) and Sumitomo HTR+.
I'm guessing i'm getting a rub with whatever that suspension arm is
that goes vertically up behind the tire and then bends toward the
outside of the car.  The clearance between that arm and the tire is
small, but i was told the space between the two remains constant as
the suspension moves. Is this not true?  Maybe i should run a 225/40-18?

I pretty much killed a set of tires driving from SF to Salt Lake City.
Inner edges on both rear tires wore thru the rubber and into the belt.
The place in Utah that looked at it thought it must've been an alignment
thing, but the car was pretty loaded down and I'm hypothesizing the
compression of the suspension caused some rubbing cuz i've not had
this problem (that i know of) in "normal" driving.

Anyone seen this?  I thought most 235/40-18's were a safe fit...Was
my tire guy wrong when he said that gap doesn't change, even when
the suspension compresses?

Thanks!

	-rich, 2000 S4