I know N2 is being used in tires in many different areas. Some of those are in airplane tires, NASCAR tires and other forms of racing. It is claimed that N2 filled tires are more stable because of the size of the molecules of N2 and all. I just feel as though it is a relatively new thing to use them in personal vehicles. I have stopped into a few tire shops to inquire about how/where they get the N2 from. The comman response is "from the green compressor". So they are pushing something they know little to nothing about. I have seen where tires filled with N2 have rotted out. Now granted this was on military equipment that saw little to no road time. So did they rot out becasue of the use of N2 or just old age? Till I am able to answer that question I will continue to put the good ol american fresh air in my tires.