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.



The EPA has also estimated that under inflated tires cause the loss of more than 2 million gallons of gasoline every single day. A tire with low pressure starts to flatten which adds additional surface area between the tire and the highway. This increases friction between the road and your car and results in your engine needing to work harder.

When an engine works harder it uses more fuel. The more under inflated the tire is, the greater the surface that meets the highway. This in turn adds more friction and more gas is used. As the friction continues to increase it takes more and more energy to move that tire. More energy means more fuel. If a tire is properly inflated it will roll easily using less energy and less fuel.

What does this all have to do with nitrogen? I'm getting to that. So we have established that under inflated tires use more gas. Why do tires become under inflated? The simple answer, it looses air. That doesn't mean you have a leak.

Tires are made with permeable materials. That means that the small air molecules can escape from the tires over time. As the molecules of air escape the tire looses pressure. It is a natural occurrence for all tires. That is why it is suggested that you should check your tires once a month.

The pro nitrogen camp suggests that tires inflated with nitrogen loose pressure 3 times slower than tires with air in them. This is explained by basic science. Nitrogen has a higher density than oxygen. Because of that, nitrogen has larger molecules than oxygen. The larger molecules of nitrogen will not filter through the permeable material in the tire as easily as the smaller oxygen molecules. . That results in a slower loss of tire pressure over time.

Your car's tires will maintain themselves at full pressure longer when filled with nitrogen because the gas loss through the tire is so much slower. The result is tires that roll with less friction, and that translates into less gasoline needed to move your car which means better fuel economy.

The price to fill your tires with nitrogen is around $40.00 per set of 4 tires. Is it worth $40.00? Those who support nitrogen as a substitute for air say absolutely it is. There is, however another side to this issue. There are those that argue that it is not worth $40.00. It might be worthwhile to find out why critics of nitrogen suggest not using it before you commit to spending that $40.00.