One of the biggest drains on fuel economy is under inflated tires. The National Highway Traffic Safety Administration says that properly inflated tires can improve gas mileage by nearly 3 percent. The EPA estimates that at least 30% of the cars on the road have at least one under inflated tire.



It is estimated that under inflated tires are responsible for the loss of more than 2 million gallons of gas every day. A tire with low air pressure begins to flatten which creates additional surface area between the tire and the road. This increases friction between the tire and the road which results in the engine needing to work harder.

When an engine has to work harder it burns more gas. More tire surface due to under inflation means it takes more power to roll that tire. More power needed means less fuel economy. A tire that is correctly inflated is going to roll more easily using less power from the engine and less gas.

How does all of this relate to nitrogen? It has to do with how tires loose pressure. As has been described earlier under inflated tires require the engine to burn more gas. But why do tires become under inflated? It is a common characteristic of all tires, they loose air over time. That doesn't mean you have a leak.

Permeable materials are used in making tires. The permeable material allows the small oxygen molecules in the air to escape from the tires over time. As the small molecules of air permeate out of the tire it results in the tire becoming under inflated. It is an malady that all tires suffer from. It is why car experts maintain that you need to check your tire pressure every month.

It appears that tires inflated with nitrogen loose pressure 3 times slower than tires with conventional air fills. This is because nitrogen has a higher density than oxygen. Higher density translates into larger molecules. Larger molecules will not permeate through the tire as easily as smaller molecules so nitrogen with it's larger molecules stays in the tire longer. That creates a slower loss of tire pressure over time.

Since your tires will loose pressure more slowly they will maintain themselves at close to the optimum pressure longer then they would with air. That means less under inflated tires, less friction, and less gas needed to move your car forward.

Of course one of the catches, (there is always a catch) is the price to fill your tires with nitrogen. It is around $40.00 for a set of 4 tires. The question is, are you going to save enough gas to offset the $40.00 investment. Nitrogen supporters say of course you will save more than enough gas. There is, however other car experts that believe for many reasons that nitrogen is not the panacea that it's supporters claim it is. Before I spend $40.00 on nitrogen, I think it would be prudent to find out why some experts won't use nitrogen. Don't run out and buy that nitrogen just yet.