Dennis: I'll drop a line to my friend @ Pirelli about getting you some 305s...

I have a pair here, but they're sold- for a 993 Twin Turbo- nice! The 305s are really low profile - In fact:
265/35zr19s are 26.31" tall
305/25zr19s are 25.01" tall

Are you sure I can't talk you into:
255/30zr19 = 25.02" tall


Here's a pic of the 19x9 255/30zr19 and 19x11 305/25zr19

 

that porsche is phat...


drew

 

I test fit a 18x10" wheel on the back with a +50 offset.

I had a 275/35 Kuhmo tire on it. The tire looked too small and the offset looked too high. I think a 285 would have worked as is and maybe a 295 if there was a tad less offset.

I drove on the 275 and it didnt seem to rub.

No guarantees on this but thought I'd share.

Ryan

good luck

 

I'm going with the 275s on 44 offset both front and rear. Thanks for all your help.

 

18x10"+44 w/275mm tire will NEVER rub on the rear......
You might even be able to do a 18x10" +47-48 rear w/285 mm tire and no fender mod.......
Option #2 would only put you 2-3 mm's more towards the "fender side". That may be the difference between rubbing and not rubbing though.
With as much space as we have to spare on the "shock side" using a 10" rear wheel, why dont more GS owners go for a +45-50 offset and then try a 285 tire. I have 19x10" +41 w/285 tire, and I feel like had I gone with a +45 or higher, I would not have had any rubbing issues.......
Can someone explain why the "NORM" seems to be between +38 and +41 on either a 9.5" or 10" rear wheel???? These widths with these offsets leave alot of room to play with on the "shock side".......Is it a fear of losing lip size????

 

problem is one say i'll be running a 900RWHP GTE motor and 6-Spd Getrag tranny... simaller to your car.

are u using a single turbo or twins?

dont belive me now, but you'll see soon.

 

I have done this on my GS and it worked. (285/35/18 18x10+48) That said, it was quite close, and I dare say a car with less camber would rub so as a business owner I am not recommending it. For the "enthuast" type, I'd highly recommend it.

All kinds of reasons for this.. some involves physics (structural), sometimes it's lip size, while other times the reason is simply the types of cores the wheel company has purchased or machined.

 

Thanks for any help!

I was well aware of the diameter difference I am just such an S03 fan.. (I've used them all). I saw that 255/30/19 but after chasing this 305/25/19 for so long, I figured there's no point. If you know of a way, I am all ears. Thanks.