I'm no expert on nitrogen versus air inflation, but I've been getting my Vette tires installed at Tire Rack (located here in Northern Indiana) since buying my first Vette, and I consider them to be experts on most things tire and wheel related.
Here are their thoughts on the matter:
- Nitrogen is a gas and is still affected by changes in ambient temperature (about one psi for every 10° Fahrenheit). Nitrogen filled tires will require pressure be added during the fall/winter months as ambient temperatures and tire pressures drop.
Nitrogen is good but can't change the laws of physics.
- Nitrogen reduces the loss of tire pressure due to permeation through rubber over time by about 1/3. This helps maintain the vehicle's required tire pressures a little longer, but doesn’t eliminate the need for monthly tire pressure checks. This is good for people who don’t maintain their vehicles well.
- Nitrogen is non-corrosive and will reduce oxidation and rust due to the absence of oxygen and moisture. This will help minimize wheel corrosion to promote better bead sealing. Tires that are used routinely will be replaced long before any life benefit would be received by using Nitrogen. This is most beneficial for drivers who drive their vehicles infrequently (car collectors, track drivers, snow tire users, motor home owners, etc).
- Nitrogen is a dry gas and will not support moisture that could contribute to corrosion of the tire’s steel components (bead, sidewall reinforcement and belts) due to the absence of moisture over extended periods of time. However it’s important to remember that atmospheric pressure is constantly pushing oxygen and moisture into the rubber from the outside of the tire. This is especially good for low mileage drivers who don't wear out their tires quickly or those that run average annual mileages but use long wearing radial (60K and 80K warranted) tires.
- Nitrogen assures more consistent pressure increases due to increases in operating temperatures in a racing environment because of the absence of moisture. This is especially good for participants in track days, high-performance drivers education schools and road racing.
- Drivers should use standard air if pressure adjustments are required when a local source of nitrogen can’t be found during a trip. While this reduces the benefit of higher nitrogen content, it is far better than running the tires underinflated in search of a source. Often the original nitrogen provider will refill the tires for free or a nominal cost when the driver returns to his hometown.
Tire Rack - Tire Tech - Nitrogen