A guy at work was talking about how he just got Nitrogen fill in his pick up. He told me how it was better to have N2 in the winter months because of the constantly changing pressure and temperature.
see Charles Law
It got me thinking. Has anybody used anything other than air or N2 in their tires?
As a diver I use Argon, Helium, Nitrogen and Oxygen in different mixtures on a regular basis. Well, I would like to use Argon more as it is winter and friggn cold. Breathing gas used is always determined by depth and duration. 90% of the time it's plain old air.
From what I've read about these N2 fills is that O2, the 21ish% of Air, eventually seeps out. A 100% O2 fill would not likely be a good choice.
Helium is a very light gas and conducts heat very well (about 6x better than air I think). You can see how this would be a problem, especially for you track rats. See Charles Law. Have you ever checked your tire pressure cold and then again after a 20 minute ride? It's usually a few PSI greater when it warms up.
Argon would probably be my best choice. That is, if it were more affordable.
Argon is a denser gas and is not a good thermal conductor. If it were in your tire it give you significantly less expansion. I don't know however if it would have an effect on traction. I guess it depends on your tire quality.