Originally Posted by
phughes
No, they use nitrogen because it has more a consistent contraction/expansion rate, making it more stable. The tire pressure remains more consistent than it would using regular air. It has nothing to do with the moisture in the gas mixture.
Again,
I dislike responding to a 12 year old thread but ...
It's the moisture in the gas mixture that cause the inconsistencies. The inconsistencies would be less if the air used was dry. Water does hinky things with temperature that other gases don't. Dry gases increase in pressure with temperature in a linear fashion (Guy-Lusaac Law). Water's increase in pressure with temperature isn't linear. It's actually exponential.