Originally Posted By: HerrStig
Originally Posted By: MWisBest
Originally Posted By: ejes
I can't remember where it is, but I just read a study where study showed, if I remember correctly, that regular air eventually seeps into the tire over time and dilutes whatever percentage of Nitrogen is in your tire.
Interesting, I had been under the impression that the opposite is true: the more you need to top up your tires with regular air, the higher the concentration of nitrogen gets. If oxygen is the problem and 'leaks out' like the nitrogen believers claim, and the nitrogen doesn't do that, then over time your tires eventually become more and more nitrogen-concentrated anyway.
When I got new tires last year I needed to add air fairly often. Now they're very stable, but of course correlation does not imply causation.
Nitrogen atoms are SMALLER than Oxygen and would leak more quickly. Rubber is a porous solid. Helium atoms are very small and leak when other gases won't. Sam Adams is selling BEER with Nitrogen added instead of CO2 the smaller bubbles are supposed to make it taste better. I'm waiting for someone to buy me one. May be a long wait.
Yes, Nitrogen atoms are smaller than oxygen atoms, but it's molecular Nitrogen and Oxygen in the air and molecular Nitrogen used in tires. Nitrogen molecules (N2) are larger than Oxygen molecules (O2) by around 3%. It's how the atoms are bound together, not the size of the individual atoms that makes Nitrogen slightly larger and therefore less likely to seep through the rubber.