A tire filled with "plain old air" can lose 1.5 psi in less than a month

Nitrogen in tires is becoming a popular replacement for standard air. Nitrogen is all around us... the air we breathe is 78% nitrogen, 21% oxygen and the rest is small amounts of other gasses. When it comes to tire inflation, nitrogen has many advantages over oxygen. With nitrogen tire inflation, improvements can be noted in a vehicle's handling, fuel efficiency and tire life through better tire pressure retention, improved fuel economy and cooler running tire temperatures. Here at Crowley our goal is to provide consumers, fleet managers and others information about the benefits of using nitrogen in tires.

Nitrogen In Your Tires: Safety First
You and your family will be safer when you’re riding on nitrogen.
Every day – as you drive to and from work, drop the kids at daycare or soccer practice, buy groceries – air is constantly escaping through the walls of your tires. Oxygen molecules, which are smaller than nitrogen molecules, seep through three to four times faster. A tire filled with “plain old air” will lose 1.5 psi in less than a month; with nitrogen, this can take six months or longer.
If you’re not constantly watching your tire pressure, escaping oxygen leads to under-inflated tires.
According to the National Highway Traffic Safety Administration (NHTSA) at the U.S. Department of Transportation, approximately 41,730 people were killed and 3,031,000 were injured on the nation's public roads and highways in the year 2001. NHTSA estimates that proper tire inflation could help save 50 to 80 lives and prevent 6,600 to 10,600 injuries each year.
With nitrogen in your tires, they will maintain proper pressure longer. Properly inflated tires not only reduce the chance of a blowout, they also ensure that the recommended “contact patch” is on the road. That improves your vehicle’s handling so you can react more quickly and decisively in potentially dangerous road conditions and situations.

With gas prices going up every day, every little bit helps.
Nitrogen in your tires maintains proper pressure, which keeps the recommended “contact patch” on the road longer and reduces rolling resistance, which translates to better fuel economy. In fact, properly inflated tires can improve your gas mileage by about 3.3 percent. That’s a savings no one would scoff at.
But that’s not all. With nitrogen maintaining more consistent pressure, your tires won’t wear as fast on the shoulders from under-inflation or in the center from over-inflation.
There’s more. By replacing oxygen with nitrogen, there is less oxidation. Oxidation occurs when oxygen reacts at high temperatures and pressures, and it damages inner liners, belt packages and rims. In fact, some tire manufacturers claim nitrogen use extends tire life as much as 25 percent.
With nitrogen, you won’t have to have your tires serviced as often and, in the long run, you’ll buy fewer tires.

Nitrogen Can Be Used in Any Tire
Nitrogen can be used in any tire, even the ones you already have on your vehicle. With it in your tires, it will enhance handling, improve fuel efficiency, extend tire life.
GM Fleet & Commercial Tech Tips – Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing.
Goodyear Tire - Goodyear supports the use of nitrogen, as an inflation gas, in all Goodyear, Dunlop, Kelly, Associate Brand and Private Brand products, based on the ability for a tire to retain pressure for a longer period of time.