There are many reasons to use pure nitrogen in tires.
Air is 78 percent nitrogen, just under 21 percent oxygen, and the rest is water vapor, CO2. There are several compelling reasons to use pure nitrogen in tires.
First is that nitrogen will migrate less through tires than oxygen. So your tire pressures will remain more stable over the long term.
Humidity (water) is a Bad Thing to have inside a tire. Water in a tire, causes more of a pressure change with temperature swings than dry air does. Just about every race car, airplane, and heavy equipment tire is filled with nitrogen. These vehicles subject tires to extreme temperature conditions, and the use of nitrogen allows better control over tire pressure as tire temperature increases.
Your choice depends on how you use your vehicle
The following are several scenarios where using Nitrogen would be very beneficial.
*If you have one or more cars that are primarily used at the racetrack
*If you drive very sparingly and your car sits unused for an extended time
*If you own collectible cars that are seldom driven any great distances
*If you have to put your car in storage for a significant period of time