There should be a sticker on the door jamb that will list the correct tyre size and the air pressure you should put in. You may have also noticed that there is a pressure on the side of your tyre. This is just the maximum pressure.

There should be a sticker on the door jamb that will list the correct tyre size and the air pressure you should put in. You may have also noticed that there is a pressure on the side of your tyre. This is just the maximum pressure.