| Because of its larger molecular size, nitrogen - a dray non-flammable gas - migrates through a tire three to four times slower than oxygen. A tire filled with “plain old air” will lose 1.5 PSI in less than a month; with nitrogen, this could take three months longer. | Under-inflated tires wear quickly on the shoulders and over-inflated tires wear in the center. In addition, removing oxygen eliminates oxidation and condensation that can damage inner liners, steel belts and rims. |