Originally Posted by ecksreturns
THANK YOU SO MUCH!! I knew I would get some awesome and sound technical advice. I did indeed decide on 255/30/20 front and 305/30/20
rear for the HRE P40's riding on P Zero Nero's. I am also getting the BBK upgrade when the wheel change, so I will definitely post new pics as soon as I get the parts.
As always , LMB gives the best advice!
I hope that rear tire size was a typo.
The diameter of a 305/30/19
tire is way too big for our cars (27.2"), especially since you have lowering springs.
The stock rolling diameter
for our cars is 26.3".
that I recommended, is the correct size for your upsized wheel application. (26.1") It's the closest size to the stock tire diameter. That will give your wheel/tire combo the necessary room to compress without causing a tire rub once the suspension geometry changes. (as you ride over bumps, dips and potholes) You'll rub like crazy if you don't do this...
You should cancel the order for 305/30
/20's, and purchase a set of 305/25
/20's, since they will not rub on the wheel liners or fender. You do not have enough clearance to accomodate the larger tire in this case.
BTW: Pirelli makes both sizes in the NERO's, so this is an easy fix. (no need to change tire brands)