I noticed the same inside wear on my P-Zeros when it came time to replace them. I had always thought this would only be caused by over inflation. I always keep my tires at proper cold inflation so I decided to ask Pirelli...
Website: www.pirelli.com/tyre
Subject: Center Tire Wear
Message: I have a 2011 Chevrolet Camaro with p-zeros. I religiously maintain Chevrolet's recommended inflation (checked cold) however my rear tires show more wear in the center as would be expected if they were over inflated. What would cause this abnormal wear?
Thanks.
Here is their reply...
It is not uncommon for high horsepower/torque rear wheel drive automobiles to experience this wear pattern, and therefore there is no concern regarding a potential materials or workmanship issue based on your description of the wear pattern.
However, when in doubt, we always suggest you have an authorized Pirelli dealer inspect your tires should you have any concerns regarding the structural integrity of your tires.
Attached is a PDF file of our warranty brochure which provides detailed information regarding Pirelli warranty procedures concerning the tires fitted to your Camaro.
Kindest regards,
Pirelli Tire North America
Quality Technical Representative