You may already know that improperly low tire pressure drops gas mileage and hurts handling. I was not aware of this solution. From Fill ‘Her Up… With Nitro:
In a tire filled with compressed air, the oxygen molecules tend to “migrate” through the wall of the tire over time. That’s why, when you open the garage to check on your aunt’s dust-covered 1980 Pontiac the tires are often flat.But nitrogen molecules migrate 3 to 4 times more slowly than oxygen, so tires stay properly inflated longer. There are other benefits. Nitrogen retains less heat than oxygen and therefore allows tires to run cooler.
While nitrogen is dry and benign and will not combine chemically with other materials (the metal in tire rims, for instance), compressed air contains trace amounts of water and the oxygen tends to combine with other materials, causing rust and corrosion. If you were to see the inner face (the part enclosing and sealing the inside of the tire) of some fancy aluminum wheels you would be surprised at how corroded they become due to oxidation.
Tour de France bicyclists fill their tires with nitrogen. So do NASCAR, Indy and Formula One racing teams, over-the-road truckers, some fire departments and the U.S. military.