The 997 GT2 uses 325/30/19 rears with 235/35/19 fronts.

If the GT2 uses the same ABS/PASM computers as the Turbo we should be able to run 325s on a Turbo as well.

Tirerack does not list a Porsche approved tire in this size yet. Even the Michelin website does not list one yet.

I think that this will change with the introduction of the GT2. When is it coming?

The diameter of the 305 tire is 26.3", the 325 tire is 26.7". Should this be a deviation within the tolerance allowed?

 

Those tires are Michellin Sport Cup tires. That's why you're not able to find those in PS2 trim.

 

I wouldn't do it. The Gt2 has no 4wd differential. The TT does, and it is quite sensitive to variations. If you increase the height of the rear tire, you would have to increase the front proportionally and you should be ok

 

I believe the rear are 305-30-19 stock, so you should be OK. Keep in mind the GT2 uses different wheels with 12" width. They look like RS wheels but they are unique to the '2' I believe. But agree with Lou, try and stay within spec with the supersensitive awd system.

 

I remember someone posting here or on another site that they went up one size to 315's and it totally threw off the handling. They recommended against it.

 

You can go without a problem to 325 on 20's

Mike

 

I think maybe 325 will fit...but you have to change your front tire size because of the 4WD system.....