Can I run 235/40/18 front and 315/30/18 rear tires on my stock rims instead of the standard 225/40 and 295/30 on the TT? I figure more tire equals more traction.

Do I sacrifice anything with this setup? Would I have to roll the fenders due to the increased height and width of the tires? I am curious to know if anyone here has done this.

 

Does the fact that the GT2's wheels are 8.5" wide (front) and 12" wide (rear) mean it's tires wouldn't work on the Turbo's wheels?

 

interesting Q...
Many here with aftermarket wheels do run 235 fronts on 8.5" wide wheels and 315 on 11" wide rears...

 

Good point, Doc. I know a 235 width tire will fit nicely on an 8" wide rim and as msindi mentioned, many folks do run 315 rears on 11" wide rims.

I assume the speedo calibration may be slightly off due to the increased diameter of the bigger tires but who really cares! Are there other factors that may affect performance/handling with this setup?

 

only thing you wanna make sure is to look at your tires manufacturers specs and make sure that the difference in OD between front and rear (or revs per mile) figures are within 3% of each other so you dont mess up your AWD viscous coupling...
Note that calculating OD using the numbers on the tire is NOT good enough as a 315/25 19 has different OD depending on manufacturer...

 

I'm doing it now. No issues, no rubbing. I'm using pilot sport tires.

 

That's what I wanted to hear. Do you feel any improvement in traction and handling compared to the stock setup?

Since you say 'no rubbing', is your car lowered?

 

I I do this, I plan to use Pilot Sport N-rated OE tires for the GT2, so it shouldn't be a problem. Thanks.

 

Do you have pictures?

 

car handles like on rails.
pictures on my website

 

GT2 sized Michelin tires on Gemballa wheels (8.5" front, 11" rear) with a slightly more aggressive offset than stock -- no rubbing issues.....