I posted this on my journal but thought about sharing it in a separate thread for warning as many people as possible.

I went to the tire shop today to take delivery of my track wheels and, in all modesty, they looked great. We went for 18" to save some weight and $$ for frequent tire replacements. The Porsche 991 documentation did not mention any issue about 18".

http://www.flickr.com/photos/60293300@N06/7316764436/
Now the bad news is that the shop had checked the fitment on the front wheels (brake clearance) and assumed it was OK at the rear. Bad call: there is a clearance issue at the rear wheels and the lower control arms are touching the rims. In conclusion: 18" wheels will not fit on a 991.
This may have seemed obvious to some and I could have done some research but I trusted the shop. They addressed it very professionally and I'll get the same wheels painted GT3RS red in 19" next week. Lesson learned!

The good news is that I'll be able to fit a bigger Brembo BBK!

 

Anyone else have different results with different 18inch wheels? I have a friend with a 2006 911 Turbo with extra wheels that I could get for a good deal if they will fit....

 

No 18" barrel will clear the lower control arm in the rear. In fact, only a few 19" wheels will clear properly.

 

SM_ATL,
18" for front has no problem?
I'm thinking abut going 18/19 combo just like my previous NSX.

 

well that's a very interesting tid bit of info i just learned. So the CUP cars etc must have different rear control arms then because they run 18's

Edit: I'm sitting in the garage and sure enough that lower control arm is hanging low