Originally Posted by FlashBazbo

Well, my friend, I don't fill my tires with oxygen, and neither do you. Oxygen would pose an explosion hazard in that application. And, truth be told, it's not the oxygen which causes the expansion and contraction issues in aircraft tires (it's the water vapor in whatever gas you use to inflate a tire).

I fill my tires with 78% nitrogen (a/k/a "air"). It hasn't shown any pressure differential issues yet. If you will do your research, you'll find that many tire dealers sell "nitrogen" which is also 78% nitrogen. Some of them DO run it through a dehumidifier first, though.