I currently have a set of 245/35r20 and 315/30r20 on a set of wheels i refinished, i know stock is a 305 though. Will the increase in rear tire size be too much for the awd system? Cross posting in here as wheel tire forum seems to be dead.

 

Stock is roughly 1.7%

Your setup is roughly 2.6% That's getting high for AWD.

But the 992 is even higher at roughly 5% but you would think Porsche programming would compensate for that.

Someone in here should know the spec for the 991.2

 

Wheels Boutique specced the HRE wheels and tires for my 991.2 TTS in 20x9 and 20x12 with the tires sizes you posted (PS4S Michelins). Its been perfectly fine.

I don't know if the wheel width on the back makes a difference or not, so YMMV. I think the stock width is 11.5 wide? Can't remember.

 

Appreciate the responses, i will run them for now then. Yeah i believe the stock width is 11.5. The wheels i have are 12.5

 

What brand/model of tire? Need to keep in mind that in a Mich PS4S, the 305/30/20 NO tire has a wider treadwidth than the 315 universal (ie not available in NO).

 

They are Cup 2

 

I run Cup2's on my TTS and just stick with stock size. What a tire! Prepare to scare your passengers!

 

i would stick with stock size, however i do not think a 305 on a 12.5" wheel would work.