Busting the Nitrogen
Saves Gas Myth
By
Scott Siegel
http://www.beatthegaspump.com
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 the most basic principle of all. Take a
deep breath. Now let it out. You realize that the breath you
took was 78% nitrogen. I'll bet you couldn't tell. Therein
lies the biggest problem with the theory that nitrogen is
better than air. Air is already 78% nitrogen!
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.
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 your tires off with air
to bring them back to the proper pressure. Now you have
almost all nitrogen in the tire that you added a small
amount of air to. At that point you would have much less
oxygen in the tire than you did when you first inflated it.
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.
Based on the claim that oxygen would leave the tire faster,
you would end up with nitrogen filled tires while filling
them with air. If this were the case then what would be the
point of filling your tires with nitrogen to begin with?
This is just a common sense answer as to why the claims of
nitrogen being a significant factor in reducing gas
consumption just don't hold up. There many more specific
scientific answers as to why the nitrogen claims are false.
Most of them are way to complicated to try and explain in
one short article. In the end it seems you are seeing the
one law of physics that seems to manifest itself over and
over.
Once again there are those who are taking advantage of a
situation to make a buck. Who finds an advantage to filling
tires up with nitrogen? Those selling the equipment and
those retailing the nitrogen. They earn more profits. Who
gets the short end of the stick? That' right, it's the
consumer.
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Scott Siegel is the author of a 143 page manual of industry insider information
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.
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