My Boxster wheels. 7x16 225/50, 9" wide at sidewalls, no spacers, et40. No contact on inner sheet metal. Rolled fenders for plenty of room & adjustment. I usually run a 15mm spacer making it et25.

9mm less offset than the 911R wheels.





Fuchs reps 7x15 225/50, 9" wide at sidewall, et23. (9.5" wide at sidewall for 8x15 225/50). The 8x15 didn't fit under my fenders as the extra 1" is on the outside (same backspacing as 7x15)

^ Yep, which explains why I was able to get a 215/60R15 on a 15x7R into both fenders with the car back on its weight.

Both the Avon CR6ZZ and Pirelli P6000 list a section width of 8.8 inches when mounted on a 7-inch wheel. But that tire is gonna need a little more room to "walk around" under load and with the suspension under compression. Question is how much? Or, rather, how much more than 0.2 inch? Someone mentioned 5mm per side is enough (so 10mm total, or .39-inch), but I'm guessing it'll need to be more than that?

Michelin lists the new Pilot A/S 4 225/50R16 with a section width of 9 inches on a 7-inch wheel, which is closer than the 215/60R15 than I would have thought. Toyo RA1 and Pirelli Trofeo R list a section width of 9.2 inches. Yoko Advan A052 lists a section width of 9.1 inches on a 7-inch wheel—so the 225/50R16s would require a bigger stretch…but these are all great tires (as anyone who has tried the A/S 3 knows…and the rest are R-compound wonders).

I guess the question for those who have pulled rear fenders is: How much room have you snuck in back there without paint work? I am guessing not much…

Problem is at 9" you are either going to have to be exact with the offset or flexible with the camber.

Also the camber will change with susp travel so don't be surprised if it rubs the inside on bumps.

I got another 1/2" or so and didn't try to save the paint, which fractured off.