[RussRamz]

Nitrogen isn't affected by temperature changes like the 'regular' atmospheric mix. If you run your car on the track where tire pressures are critical for maximizing performance, then nitrogen is the way to go. If you are a daily driver kind of guy, then it makes no sense to use nitrogen unless you get it for free. Another benefit of nitrogen is that the larger molecules are less likely to seep out of your tire over time, thereby retaining a constant pressure over time better than that of a typical earth atmosphere mix.