Just went through this with my service advisor.

Between the manual, the door jam sticker, and TPMS target for a specific setting (20", summer, partial load, comfort setting, etc), the numbers are all over the place.
The TPMS targets don't match what's in the manual or on the door jam.

SA suggested to set TPMS to the tire setting you want (mine above), then inflate/deflate to that.
Not that it should make a difference, but I have PS4S tires.

 

same

 

Don't shy away from the PS2s I've found them to be surprisingly comfortable and sticky when needed. Switch to Sotto Zeros in late October, early November,.

 

Thanks so much. This is awesome info.

I’ll consult the manual and back down my pressures. I’ve been running full load but now understand why I should not. The ride has been a bit bumpy, now I know why.

i love driving “twistys” but do drive around town a decent bit too. It’s not my daily though.

Again, thanks for the help.

i had posted a question a while back about Michelin Pilot 4S versus Pirelli P Zeros. I’m about due to change tires. I really have enjoyed the P Zeros but everywhere I read, the P4S is better. I have Michelins on my other cars so I think I’m going to try those. Any input is always appreciated though.

 

What about a 997.1 with new (300 miles or so) Pilot Sport 4S for spirited mountain driving?

 

start at the recommended tire pressure per the manufacturer and adjust from there according to your preferences. in 991 land that's somewhere in the 30/36 territory.