[RedDevil]

Hmm. That's funny.
This goes against common sense thinking.

You air up the tires to max sidewall when the car is empty. Then load the car to max capacity.
What do you expect the resulting tire pressure to be?
Much higher, right?

But no. The pressure rises less than one PSI.
Because it spreads over the full volume of the tire, while the higher weight does press the suspension down and the tire harder to the pavement - but that only enlarges the contact patch by a little bit, so the total reduction of the volume inside the tire is only fractional.

In fact, the higher the pressure is, the less it will rise if you fully load your vehicle.
When your tires are underinflated then their pressure will rise some when you load the vehicle - that is, until the rim squeezes all the way down to the thread...