I have been reading old threads about this until my eyes bleed but have what I believe is the solution that allows me to get the Michelin PSS tires for my 996tt that I have come to love on all my other "Sports Cars)

Please let me know if I am on the right track.

With 19” s (8.5" & 11")
Front 245/40/19 = 26.8" diameter
Rear 305/30/19 = 26.3" diameter
Ratio 1.019

Stock
Front 245/40/18 = 25.3" diameter
Rear 295/30/18 = 24.9" diameter
Ratio 1.016

Note in both cases the rears are shorter, by deduction, the rears are supposed to turn faster than the fronts by Porsche design. Providing there is not a rubbing issue, this should be the correct size….right??

 

I believe that stock fronts are 225/40/18, which are typically 25.1" tall.

 

See this definitive post by King James for pretty much all you need to ever know about tire sizing for these cars.

I went with the tried and true 245/35-19 & 305/30-19.

-V

 

Vendetta, I am pretty low on KW V-3's, do you get any rubbing on full lock or compression?

 

No, but I'm still on stock suspension.

-V

 

295/30/19 out back with the 11" if you're going to lower. 245/35/19 up front is perfect - no rubbing lock to lock.

I'm running 305/30/19's on a 19x12 and have run GT2 fender liner brackets, rolled fenders, and a variety of spacers to adjust wheel placement and i still rub over large compression's (lowered on H&R springs so the car is on it's face).

If I was to do it all over again I would do 19x11 with the 295/30/19 and go live a happy rub free life. No reason to run the 305 IMO.

 

*grumble* need more 18inch options