Is it worth filling your tires with Nitrogen?

We are often asked the question:  "Is it worth filling my tires with Nitrogen instead of air?"  We're here to shed some light on the topic.

First of all, we have to look at the terms in question.  "Air", meaning our natural atmosphere here on Earth, is actually mostly Nitrogen anyway-- about 70-80% Nitrogen, in fact.  The rest is Oxygen, Carbon Dioxide, water vapor, and other trace elements and compound.  Does that fraction of Oxygen really make a difference in your tire pressure's reliability?

The answer is yes.  Sort of.  Even though Oxygen atoms are heavier than Nitrogen atoms, they are actually slightly smaller.  Why?  Electromagnetism.  Oxygen atoms possess one more positively-charged proton than a Nitrogen atom-- thus pulling the negatively-charged electron cloud just a hair closer to the nucleus of the atom, resulting in a smaller overall atomic radius.

The smaller Oxygen atoms leak out more easily through the walls of your tire than Nitrogen atoms.  What's more, pure Nitrogen will contain almost no water vapor-- which changes states quite readily, condensing into water in the cold and back into a gaseous form in the heat.  The result of filling your tires with pure Nitrogen is a far more reliable tire pressure that lasts for far longer than simply using air.