Quote:
1st997 said:
The present composition of the atmosphere is 79% nitrogen, 20% oxygen, and 1% other gases.....



The problem with "normal" air in tires is actually WATER.
When heat builds up, the water evaporates and...tire pressure gets lower. One reason some racing teams are using nitrogen in their tires, it keeps the tire pressure constant for a longer while. No other reason (unless they believe in Santa... ). Nitrogen in tires was "a la mode" over here in Germany a few years ago, it was possible to recognize the tires filled with Nitrogen by a green valve cap. Not sure if they still do it.