Proper inflating is the most important thing in tire care. Note that the steam pressure recorded on the outside of the tire is only the maximum working pressure, it is not necessarily the pressure that your vehicle needs to reach. Please apply the pressure recommended by your car manufacturer. You can refer to this pressure in the Vehicle User's Manual, either in the car door on the driver's side or in the paper trunk.
Always check the air pressure when the tire is cooling (ie the car has been off for more than an hour or has only been running a few kilometers). Use a good pressure gauge. Note that for radial tires, when inflating to the right pressure, the sidewalls slightly inflate, which is normal. You should regularly check the pressure every 2 weeks, especially when there are long trips or heavy loads.