Tires: air pressure, guage, air pressure

Question
  hi..i have a question; think this is kind of strange. i went to the air station yesterday and put 46 p.s.i. in tires that are maybe 6 months old. they were hot at the time, and the guage said 46 p.s.i. i went home and put the car in garage. next day, checked with guage and one tire had 46 psi, and the rest of them were at 40. you can go up to 44 psi with these. what in the world would make that happen to tires 6 months old? my girlfriend is taking the car on a long distance trip next month, and of course we dont need tire probs. thanks so much!

Answer
James,

The first question I have to ask is:  Why would you put 46 psi in a tire?  The proper pressure for a tire is not written on the sidewall - it is written on a sticker, commonly called a placard, and those are usually located on a door post or in the glove box.

The second thing is that if the wheels leak, it doesn't matter if the tires don't.

Hope this helps.