Another one to explode your head...
Save Big on Gas by Filling Your Tires with Nitrogen
It prevents the tire from getting "Squishy".
The end result is that it is maintaining the pressure that is important.
And that's exactly what they say at the end anyway.
Oh; by the way, there's no danger in mixing a nitrogen filled tire with regular air.
Oh; did we mention that air is over 3/4 nitrogen?