307 tire air

Hello yesterday, I showed the tires of my vehicle to a tire on the road and the tires of the vehicle came out and the air hit the rear tires made 30 psi to the front tires, why did I say less, in winter, we hit the front a little bit in order to prevent slipping in front of the car. At 30 in 28 settings but I'm not sure whether it should be.

I also had 307, I was making all four tires 30, a friend in the service said so ...

okay then let me do one more thing, i will ask you if the door of this vehicle writes 2.5 bar there is 36 psi at this value. is the value written on the door the highest value that can be applied?

My friend presses 30 bars on all 195 rim tires and 32 bars on 205 rims.

michelin in site shows 33 bars unloaded.

Hello ,

Friends said service, friend said they don't do business with them.
The car has an operating manual, it says 2.5 bar without load on the front, 3.0 bar on the loaded back.
Convert the bar measurement from the net to psi, the value of mortal comes from. This is what it should be.