The reasoning behind using dealership PP for selecting tires is that it's an easily obtained verifiable number that everyone can see in their game. Using the broken in PP would require that number to be provided in a timely fashion (which it isn't always) so that it could be posted and drivers could practice as soon as the pick was made without having to wait for the PP number to verified so the tires could be selected. It's a way of keeping it simple and not making any more work for those in charge of regulating such things. I know how much time I put into this league and it's a fraction of what some other put it. Anything that is plug and play without having to go verify it is welcome in my eyes.
Basing tire selection off of the torque figures alone seems a little shortsighted in my opinion. It would allow for grip under acceleration but would not account for lateral grip or grip while braking. With the tools that we have at our disposal, PP is a much better indicator of overall vehicle performance than torque alone.
Once GT6 comes out, we can revisit the tire selection guidelines along with everything else that may or may not need to be changed with the new set of tools we get in GT6.
Last edited: Sep 11, 2013