Hi Guys,

My 17 R AWD is due for new rear rubber. Currently running the original equipment 295/30-20 P-zeroes on the rear, 255/35-20 on the front.
I want to widen to 305 rears, which should fit fine on the factory carbon fiber trimmed rims. But the overall diameter is slightly larger on these tires, and, being an awd, I am worried about the change in tire diameter( it's slight)


Its not time to change the front tires yet, so can I just change the rears and run them?

Ken

 

The diameter (and circumference) of the 305/30 is only 0.7% larger than the 255/35, well within acceptable variation for AWD.

 

Hey, thanks for that.

Next question.
Pilot sport cup 2 or Pilot sport 4s or something else?

 

4s unless you want the rear to be extremely grippy vs the front aka understeer.

 

I went drag racing las t night with RWD on 305/30 4S's with no grip at all. I didn't lose a race but had to pass on every run. If you want maximum RWD bias, I would go with Cup2s or R888Rs.

 

+1. Cup2s & R888Rs for the track on dry pavement. But don’t go near any water. The PS4Ss are the choice for street service.

 

I just upgrade to 305/30/20 rear and 265/35/20 front, Continental Sport contact 6, all on Gyrodyne factory rims, way in front of the OEM Pirellis, unreal grip, dry and wet.

 

This is my current bane (still on pzeros up front).