The Myth That Using Nitrogen Increases Fuel Economy

Nitrogen as an alternative to air when filling tires seems to be gaining some popularity. The fact that Costco and other retailers are now offering nitrogen fills certainly points to nitrogen filled tires as becoming more mainstream. At almost $10 per tire does it really save fuel like it is claimed to do? Here are some answers.

Let's start with a basic principle. Inhale...., now let it out. The breath you just took was 78% nitrogen. Of course you could tell that when you took that breath, couldn't you. That is the biggest problem with the assertion that nitrogen is better than air. 78% of the air is already nitrogen!

The basic claim made by nitrogen supporters is that nitrogen will permeate through the tire slower than oxygen because it is a larger molecule. By slowing the pressure loss of the tire, nitrogen will allow your tires to maintain the proper pressure longer.

This contention is just not supported by the laws of physics. The rate of diffusion of a gas through a porous substance depends on the mass and the size of the molecules of that gas. Oxygen and nitrogen are almost the same size and in fact nitrogen is lighter than oxygen. That means that if either is going to permeate through the tire the nitrogen would actually permeate faster than the oxygen.

Think about this for a minute. If oxygen actually permeated out of a tire faster than nitrogen, then as the tire deflated what would be left in the tire would be mostly nitrogen. Let's say there was 90% nitrogen left in the tire.

You then go to the station and top off your tires which are now filled with a high concentration of nitrogen. You add a small amount of air to the tire. Now you have much less oxygen in the tire than you did when you first inflated it. It has a much higher concentration of nitrogen.

Assuming that the oxygen continues to leave the tire and the nitrogen remains you would have an even higher percentage of nitrogen in your tires. Maybe 95%. As you repeated this over and over you would eventually have nothing but nitrogen in your tire.

If this were the case, that the oxygen leaves the tire while the nitrogen is left behind, you would eventually end up with nitrogen filled tires. All the while just filling them with air. Since you now have nitrogen filled tires why on earth would you fill your tires with nitrogen to begin with and spend the extra money?

This claim of nitrogen permeating out of a tire slower than oxygen has been shown to be false just by using a little logic and common sense. There are a lot of specific laws and formulas of physics illustrating why claims of nitrogen's benefits are false. They would take many articles to explain. Really though it seems the law you are actually observing is the single most common law of behavior that is repeated over and over.

As is generally the case there are those who always take advantage of some problem to make a profit. Who gets the benefit of filling your tires with nitrogen? Non other than the manufacturers of the nitrogen producing equipment and the merchants who sell the nitrogen to the public. They make more money. Who ends up paying for those extra profits? That' right, it's you.

Article Source: http://www.christiannotepad.com

Scott Siegel has written a 143 page book of automotive industry insider secrets on saving gas and money at the pump (beatthegaspump.com). Visit us to learn how you can get better gas mileage. Find out how to increase gas mileage.
Get your own completely unique content version of this article.