A popular idea, using nitrogen in order to save gas seems to be gaining supporters. It is used as a substitute for air when filling tires . Even retailers like Costco are now offering nitrogen fills. The cost of nitrogen is about $10 per tire. Is nitrogen worth the additional dollars? The answer is no!
Basic chemistry and physics supply the answer. First, take a deep breath, hold it for a second, now let it out. Did you know the air you just inhaled was 78% nitrogen? Certainly you could tell that when you inhaled, couldn't you. That is the biggest myth buster of all in considering nitrogen versus air. Nitrogen already composes 78% of air. Only 21% of air is oxygen.
A major claim made by nitrogen advocates is that nitrogen is a larger molecule and will permeate through the tire slower than oxygen. By slowing the seepage out of the tire, nitrogen will allow you to maintain the proper pressure in the tire longer.
The natural laws of physics don't support that contention. The rate of seepage of a gas through a porous membrane depends on it's mass and on it's size. Nitrogen and oxygen are almost the same size and nitrogen is slightly lighter than oxygen. If either gas is going to seep through the tire then the nitrogen would actually seep slightly faster than the oxygen.
Applying some common logic to this can illustrate why the nitrogen supposition is false. If oxygen did escape through a tire at higher rates than nitrogen, then as the oxygen escaped, the tire would be left with mostly nitrogen. Assuming this is what happens, then over time as oxygen has been lost there might be 91% nitrogen on the residual air in the tire instead of the original 78%.
Now in order to bring your tire back to the proper pressure, you top off your tires with a small amount of air. You have in effect added a small amount of air which is 78% nitrogen to the residual air in the tire which is 91% nitrogen. The end result is your tire is now filled with an air mixture with a very high concentration of nitrogen.
Continuing this train of thought, if the nitrogen does continue to behave the same way, the smaller amount of oxygen now in the tire escapes from the tire and the nitrogen that remains behind becomes even more concentrated. Maybe you now have 95% nitrogen in your tires. As you continually repeat this process many times, you continue to get higher and higher concentrations of nitrogen in your tires. Eventually you will end up with only nitrogen.
The question is, if eventually you would end up with nitrogen filled tires by just repeatedly filling them with air, why would you fill them with nitrogen to begin with and spend the more money? It just doesn't make sense.
This is just a plain logical example as to how false the nitrogen claims are. There of course are a myriad of specific scientific answers showing why the nitrogen claims are based on myths and not scientific facts. Each one would require a separate article in itself to explain. In the end it seems you are seeing the single law of behavior that seems to play itself 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.
Scott Siegel has written a 143 page book of industry insider information on saving gas and money at the pump (beatthegaspump.com). Visit us to discover how you can get better gas mileage. Find out how to increase gas mileage.
Get your own completely unique content version of this article.
No comments:
Post a Comment