Nitrogen does not resist water vapor. It just doesn't contain humidity when a clean source is used.
Race teams (of all kinds) use nitrogen because it is more stable pressure-wise as it heats. It has nothing to do with corrosion.
So many myths about the wonders of nitrogen...
This article is not about the nitrogen. It's really about reducing oxygen and water vapor in your tires. The air in our tires is composed of 78% nitrogen, 21% oxygen and about 1% water vapor and other gases. When pure dry nitrogen is used to replace the air in your tires it improves fuel efficiency, handling and it will extend the life of steel rims or custom wheels and tires. By reducing oxygen and water vapor in your tires from 22% to less than 7%, your tires will maintain pressure three to four times longer. Plus it will keep you safer on the highway.
How does oxygen and water damage my rims and tires? Oxygen, especially at high temperatures and pressures, corrodes aluminum, steel wheels and rubber. This process is called oxidation. When oxidation occurs small particles of rust and aluminum oxidization in your steel or aluminum wheels can clog valve stems, causing them to leak. The oxidation can cause the surfaces of your wheel flange and tire beads not to seal properly causing another leak point.
Oxygen can also age the thin layer of rubber called the inner liner or radial ply. As the inner liner ages, more and more air migrates through the rubber, causing additional pressure losses. As oxygen migrates through rubber it can come in contact with steel belts and the steel bead causing them to rust.
While both nitrogen and oxygen can migrate through rubber, nitrogen does it much slower. It might take six months to lose a couple of pounds of nitrogen, compared to less than a month with wet compressed air. Dry nitrogen does not cause rust and corrosion on steel rims or aluminum custom wheels, and it does not degrade rubber like wet compressed air.