Nitrogen Fill

[darrelld]

Anyone considered doing a Nitrogen fill in their tires? Local Ford dealer does this for $40.

[jmckinley]

Air is 80% nitrogen and is free.

 

$40 for nitrogen is an incredible ripoff and does nothing for your car or your tires.

 

Check it out on any of the tire manufacturer's websites. The all say it won't hurt anything except your pocketbook but it won't do any good either.

[darrelld]

Air is 80% nitrogen and is free.

 

$40 for nitrogen is an incredible ripoff and does nothing for your car or your tires.

 

Check it out on any of the tire manufacturer's websites. The all say it won't hurt anything except your pocketbook but it won't do any good either.

 

http://blog.tirerack.com/blog/make-driving-fun/pure-nitrogen-in-tires-facts-and-myths-v1

[jmckinley]

Thanks for the link to the Tire Rack article. I've given up arguing this issue with neighbors, people on the motorcycle forums, people on the motor home forums, et al. As Tire Rack says, the only possible advantage would be from a hopefully drier gas without water vapor. My guess is even this benefit is suspect since it is highly dependent on the installer thoroughly flushing the old air and vapor from the tire/wheel before filling with nitrogen. And, if they're using a nitrogen generator, it could introduce moisture of its own.

 

It is almost a certainty that your friendly, $10 per tire dealer will simply let the air out, pump in something that may or may not be pure dry nitrogen and install the tacky green valve stem caps. Like they said, save your money, check tire pressures often, fill with the driest air you can find, preferably from your own compressor which is drained regularly.

[stephengoldberger]

Most tire shops that offer nitrogen gas fill use a nitrogen separator based on filtration.  Since oxygen is more permeable than nitrogen, it passes through the filter while the nitrogen is trapped.  The same system takes out the water vapor - I don't recall if the water vapor is blocked by a primary filter of if it passes through with the oxygen.  

 

Benefits of nitrogen include the absence of moisture (as noted).  It also reduces oxidation within the tire.  That bulge you see in the side of a tire with a damaged liner (from hitting the curb, for example) is created by oxidation of the rubber to fabric bond as much as pure pressure leaking into the carcass. The combination of low moisture and low oxygen benefits the tire pressure monitors.

 

The claimed benefit of "better fuel economy" is totally bogus unless you simply do not maintain the correct pressure.  Nitrogen will seep out of the tire more slowly than oxygen, so over time the gas inside the tire will become increasingly more nitrogen and less oxygen, and thus eventually will hold pressure almost as well as a pure nitrogen fill.  They also claim that the variation of pressure with temperature is less, a claim I also consider totally bogus - see "perfect gas law".  A simple "deflation, reflation" does not result in a sufficiently low oxygen concentration to achieve the actual benefits - it takes two deflation-inflation cycles.

 

Finally, the cost is something that may go down to zero "with a new tire purchase" as more tire vendors see nitrogen as a marketing tool.  One of the nitrogen generator manufacturers underwrites a roadside assistance plan as an inducement for car owners, something which could offer a $40 value over the life of the tires. http://www.gogreenautoclub.com/

[MikeB]

Nitrogen will seep out of the tire more slowly than oxygen, so over time the gas inside the tire will become increasingly more nitrogen and less oxygen, and thus eventually will hold pressure almost as well as a pure nitrogen fill. 

This is why I think a Nitrogen fill is pure marketing snake-oil. Nitrogen is a smaller and lighter molecule than Oxygen. What possible physical mechanism could you come up with where a smaller molecule get trapped more than a bigger one? Ever notice how helium balloons go flat far faster than air balloons do? That's because smaller molecules can escape where bigger ones can't. Unless someone can offer a plausible explanation why a tire works exactly opposite of how a balloon does, I'm calling this an anti-science myth. Pure marketing nonsense for the science-illiterate masses.

[Jus-A-CMax]

Slightly ot - Powerbilt had a nitrogen filled driver advertised with Fuzzy, lets just say it went as far as the Powwww...Powwww...Pow....Hammer... :runaway:  ...those who hang around the golf forums knows exactly what I mean. 

 

Back to the topic. I'd say go for it, it's only  $40 but do some screen shots of a daily commute as a baseline and then do the same run with the nitrogen filled tires.  :)

[Hollywoodtx]

When I got my car they made it a point to tell us that ours were filled with Nitrogen. It also is stated on our roadside assistance package along with tire caps that are color coded for nitrogen.

Forgot to add that per our service agreement we can got to the dealer and get our nitro for free.

Edited February 13, 2013 by Hollywoodtx

[plus 3 golfer]

This is why I think a Nitrogen fill is pure marketing snake-oil. Nitrogen is a smaller and lighter molecule than Oxygen. What possible physical mechanism could you come up with where a smaller molecule get trapped more than a bigger one? Ever notice how helium balloons go flat far faster than air balloons do? That's because smaller molecules can escape where bigger ones can't. Unless someone can offer a plausible explanation why a tire works exactly opposite of how a balloon does, I'm calling this an anti-science myth. Pure marketing nonsense for the science-illiterate masses.

A nitrogen molecule is larger than an oxygen molecule. There is no correlation between molecular size and molecular weight.