nitrogen or air

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southernjeeper

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Three years ago in January I decided to go with nitrogen just to do my own experiment with the actual difference in running the all "new thing" in tires. I was pleased with the fact that I never really had problems with tire pressure fluctuating because the N2 didn't seep through the rubber as bad. Or the fact I never got any nails, screws, or what not stuck in the tires to cause me any problems.

My stupid question is now that since I have had one tire plugged due to a screw and all the other pluses and con's about if I get something else stuck in the tire I tire shops that sell Nitrogen are not always around. Should I run and get all my tires deflated and inflated with solely Nitrogen once again?

I love the fact that the tread on the tires were pretty even. The fact that I kept a steady 32psi was very much a plus. But I am second guessing whether or not I shouldn't mess with nitrogen solely due to the fact that you can't just go to a service station and fill up with nitrogen when I get a slow leak in the tire...

What are your thoughts?

one last thing
With nitrogen I don't have to worry with water from air compressors ever getting into the tire, duh.

thanks for your input


lastly this is what I used as a reference on the matter those 3yrs ago.
http://www.getnitrogen.org/savebillions/index.php
 
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Nitrogen is a joke, but dry, compressed air isnt. Just use from a good shop compressor with and oil+water separator. I hear some TPMS can be sensitive to moisture, never use the coinop compressor hanging at the gas stations.
 
Sigh...not again...N2...the miracle gas, not subject to the universal gas law PV=nRT, so it never expands and contracts with temperature...and so rare that you have to pay for it...

Oh wait, that's right, regular air is 78% N2...

OK, all sarcasm aside. N2 is both dry and inert. Inert doesn't really matter in car tires, though it might in airplanes. Dry does matter, but I just wait for a dry day and fill my tires from my compressor (that is drained every day...).

I get 78% of your supposed "benefits"...for free...I really would encourage you to not worry about it...
 
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Quote:
....I get 78% of your supposed "benefits"...for free...I really would encourage you to not worry about it...
+1
Use the N2 in free air. Skip the 'pay for' variety.
 
I am a not sold on the Nitrogen fill idea yet. As i use my own compressor (which is drained of excessive moisture) I still get the 78% Nitrgen fill that everyone else does that does not pay extra for the other 22% that shops sell at a small premium. In my opinion only, I dont see the benifits of Nitrogen fill in everyday passenger cars!
 
Most of the supposed benefits - permeability, pressure stability, etc. simply are not true. A good understanding of High School physics & chemistry would tell you that...it's a sales pitch...and people buy it...

The only real benefit for passenger cars is the dryness.
 
If you have the money to tie up and the space to keep it, you can buy a bottle of nitrogen gas at your local welding supplier for very little. You have to pay a deposit on the bottle and buy a regulator, but the gas itself is cheap. You can get those little portable welding size bottle.
 
Originally Posted By: Astro14
Most of the supposed benefits - permeability, pressure stability, etc. simply are not true. A good understanding of High School physics & chemistry would tell you that...it's a sales pitch...and people buy it...

The only real benefit for passenger cars is the dryness.


Isn't the size of the N2 molecule larger than the other 20% of stuff int he air.
 
The other 22% is mostly O2. IIRC, air is 78% N2, 21% O2 and trace others...

N2 and O2 differences in atomic weight are slight, molecule size should be about the same (same electron valence)...and the other traces are heavier, and therefor larger...the actual difference in permeability between N2 and O2 is measurable...but it has to be slight...

But think about this for a second. If O2 permeated through rubber a lot faster than N2, and I then replace that leaked O2 with 78% N2, then I would be increasing the N2 concentration with each fill up of regular AIR...let all the O2 permeate out from the first filling. Replace 21% of the orginal fill with 78% N2 (AKA...Air...). Now, I have 94% N2 in my tires... Next iteration, replace that 6% with 78% N2...now I am at 99% N2...

Holy Cow! I just two iterations, I got to 99% N2 by using AIR...well...that or the permeability, while measurably different, isn't that much of a factor...

So, larger? Better? Nah...sounds like a sales pitch to me...

Don't forget that N2 permeates through the rubber as well...so you still have to fill the tires in the colder weather (PV=nRT) to keep the same inflation pressure and you will still have to top them off as the partial pressures inside/outside the tire equalize and the N2 permeates through the rubber over time...

Leave the N2 to race cars and airplanes. Check your tires monthly and fill them with dry air.
 
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I do wonder if molecules seep through if you can fill up with a heavy inert gas like argon and see improvements. I think I need to set up a gimmicky marketing campaign touting the benefits of argon. I mean everyone can say "air is 78%" nitrogen, how bourgeoisie," I've got argon. Air is only .93% argon. This is the tire fill of kings!
 
Nah! We need to start advocating the benefits of Helium inflation! Helium is light! Just imagine the weight savings! And since it permeates rubber like poo through a goose, we'd get plenty of repeat business!
 
Originally Posted By: Astro14
Sigh...not again...N2...the miracle gas, not subject to the universal gas law PV=nRT, so it never expands and contracts with temperature...and so rare that you have to pay for it...

Oh wait, that's right, regular air is 78% N2...

OK, all sarcasm aside. N2 is both dry and inert. Inert doesn't really matter in car tires, though it might in airplanes. Dry does matter, but I just wait for a dry day and fill my tires from my compressor (that is drained every day...).

I get 78% of your supposed "benefits"...for free...I really would encourage you to not worry about it...


okay, that's good enough for me...
 
Originally Posted By: leeharvey418
Originally Posted By: Papa Bear
QUIKRETE

Make that 31 good ones.

lol
 
Originally Posted By: Astro14
But think about this for a second. If O2 permeated through rubber a lot faster than N2, and I then replace that leaked O2 with 78% N2, then I would be increasing the N2 concentration with each fill up of regular AIR...let all the O2 permeate out from the first filling. Replace 21% of the orginal fill with 78% N2 (AKA...Air...). Now, I have 94% N2 in my tires... Next iteration, replace that 6% with 78% N2...now I am at 99% N2...


The really funny part about that thought experiment is that gasses play by partial pressure rules in stuff like that.

So zero partial pressure of O2 inside the tyre, and 3psi on the outside will have oxygen leaking INTO a tyre, probably about the same rate as the O2 leaks OUT of an air filled tyre.

If O2 and N2 were as vastly different as claimed, you'd have to let air out of your tyres for a while after filling with N2.
 
Originally Posted By: Shannow
The really funny part about that thought experiment is that gasses play by partial pressure rules in stuff like that.

So zero partial pressure of O2 inside the tyre, and 3psi on the outside will have oxygen leaking INTO a tyre, probably about the same rate as the O2 leaks OUT of an air filled tyre.

If O2 and N2 were as vastly different as claimed, you'd have to let air out of your tyres for a while after filling with N2.


Now here's the one that'll really blow your mind - if you don't purge the air in the tire before filling it with nitrogen, the partial pressure of oxygen in the tire will be - wait for it - 3 psi. In other words, if you're so hung up on getting your tire pressure set to a greater precision than the variation you'll see due to temperature fluctuation on a typical day in most of the U.S., the way to go is to not worry about getting the air out.

Or, you know, just fill the tire with dry air in the first place and check your tire pressure like you should anyway, regardless of your fill medium.
 
Originally Posted By: Shannow
Originally Posted By: Astro14
But think about this for a second. If O2 permeated through rubber a lot faster than N2, and I then replace that leaked O2 with 78% N2, then I would be increasing the N2 concentration with each fill up of regular AIR...let all the O2 permeate out from the first filling. Replace 21% of the orginal fill with 78% N2 (AKA...Air...). Now, I have 94% N2 in my tires... Next iteration, replace that 6% with 78% N2...now I am at 99% N2...


The really funny part about that thought experiment is that gasses play by partial pressure rules in stuff like that.

So zero partial pressure of O2 inside the tyre, and 3psi on the outside will have oxygen leaking INTO a tyre, probably about the same rate as the O2 leaks OUT of an air filled tyre.

If O2 and N2 were as vastly different as claimed, you'd have to let air out of your tyres for a while after filling with N2.


You're right of course, and you of all people know my passion for physics and accuracy, but I was deliberately trying to keep this discussion simple and not talk about the partial pressures (which much equalize over time...the time depending on the individual gas permeability through the rubber, actually, mostly the butyl liner...)...perhaps I oversimplified, but the advice remains the same.

And while Capri Racer's site is far more eloquent than I was in explaining it...we've both reached the same conclusion...based on the universal gas law and other basic chemistry/physics principles...

cheers,
Astro
 
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