How can tire pressure change overnigh?

[raghavrao]

how dose the tire pressure increase overnight??

i checked day before yesterday the pressure of one tire is 35 which i maintain all the time but today morning when i checked it was 39

How is this possible?

Anybody has had the same situation or can explain why did this happen?

[neel]

tire is made of rubber that expands and contracts on day to day basis depending on the climate outside. What may have happened is that on expansion the air may hay increased in side the tire that happens in ever tire just like the pressure goes down as well.

No need to worry this is very common in all cars.

[raghavrao]

i got all 5 tires changed. very very expensive.

[tazz]

if you would have gone to sharjah used market you may have saved some cash.