And yes, there is at least some other thoretical reasons to use Nitrogen (but not temp/pressure), however with air being 78% nitrogen to begin with, the effects are a lot less than you think. The big one would be slow oxydation of runner/rims etc. The pressure swings (like I said) have more to do with water vapor (no matter what popular mechanics says RE temperature/pressure. The issue is also NOT "Migration through the rubber" (there is a 2.6% difference in size) - any issue is actually the inner surface of the tire actually oxydizing.
Most of the benefits which are there in theory aren't really there, in practice. As I said, the BIG one is the N2 being DRY vs air typically being about 1% water vapor, which seriously affects the n in PV=nRT, so you get a fall in both n and T (multiplicitive) which will change P. That is why I'm always careful to say DRY air (my compressors usually have a dessicant air dryer on them, because paint doesn't like water - I airbrush models, so water is an issue)
I mean' if you want big molecules, you could fill your tires with Carbon Dioxide. MUCH bigger than O2 or N2, cheap, and ALMOST non reactive. If you wanted to go nuts, you could use Argon. Totally non reactive, larger than N2 (yes, more expensive, but still commonly available - any welding supply house)
