Originally Posted by Bratmanstudio
I think the thing is not so much nitrogen air is almost 80% of the stuff, though it is a lighter gas, from what I understand it's really a question of how much water -the condensation inside the air tank, that rots the inside of the tires and lessens tire life span. Tho as points out you won't find it everywhere at a local pump.
The amount of condensation varies based on humidity, the quality of the compressor, and if it had a dryer attached. If you press on the tip of the air chuck and water squirts out that's a problem. A little bit of moisture doesn't hurt anything, serious corrosion to the point it will cause harm is rare and the moisture really won't harm the tires. Your tires are exposed to moisture, rain and water puddles all the time, doesn't hurt them.
Is nitrogen a good thing to put in tires, yes it is. Nitrogen is more resistant to temperature fluctuations, it is a bigger molecule and doesn't leak out as fast, and as was pointed out it's dry. Over a period of 5-7 years will it make a difference, taking in to account price and availability, that's for each person to decide. Personally I don't think the scales balance out.