I was on track with my P3D yesterday. It was damp and the ambient temperature was around 50°.I get the data from the CSV file. I think the tires were to hard to start with and it was a cold day, so they never really heated up much. I’ll plot the data and see what it looks like.
Driving 5 laps of a 1.5 mile track my pressures went from 31/32psi to 36/37psi. The cold conditions really didn't help and I would have expected maybe a couple of psi more in that time if it had been a little warmer.
Generally, those of us running track tyres on the P3D are starting at 30-33psi to get the tyres into their operating window of 35-37psi.