Nitrogen vs Air in Tire

[Egan101]

I haven't thougt of this. Mga ilang weeks kaya bago maging 99% nitrogen ang nasa loob ng gulong?

Unless you have a good gas detector that you can somehow tap inside a tire, then you can check the presence of various gases inside. Back in chem lab class before, combustible gases (oxygen or hydrogen) are easier to weed out by a splint.

[niky]

I haven't thougt of this. Mga ilang weeks kaya bago maging 99% nitrogen ang nasa loob ng gulong?

Won't ever get there.

The Partial Gas Law means that oxygen will only leak out until it equalizes with the outside air.

So, if your tire is inflated to twice atmospheric pressure... about 30 psi (from 14.7 psi), and outside air is only 20% oxygen, then your oxygen will leak out until you have only 10% oxygen inside. Inflate to higher pressures, like I do, and it'll get down to about 6-7%.

As an aside... most pump nitrogen is only 93-95% pure.

One interesting idea, and I've mentioned this before... is using refrigerant to fill tires. I know one guy who's experimented with this, and has found that the tires hold their pressure much longer still... though filling with refrigerant is obviously much more expensive than nitro-filling!