Nitrogen in tires

[Patrolman]

So I am a bit stumped by this. I had always heard that filling tires with nitrogen made them less likely to lose air because the molecules/atoms are larger than what would be found in compressed air.

After doing a bit of reading, I am less convinced than before. Since "air" is 78% nitrogen, you really aren't getting much by going with pure nitrogen. Even IF the 21% oxygen atoms happened to leak through the tire and the nitrogen did not, and you added more air at 78% nitrogen again to replace the 21% that is missing, you would now have 95% nitrogen.

Here is some reading that I was doing:
http://www.popularmechanics.com/cars/how-to/a3894/4302788/

They do make the argument that the moisture in the air that would not be present with pure nitrogen, which is better for the tire. A drier on a compressor would resolve this, but it really is a minimal issue in Colorado. SO, I just don't see the true benefits unless it is a high performance car.

[cornpone99]

I think nitrogen is better, but unless you are racing not worth the hastle.
on my rig, I air down and up often so zero benefit there.

[Swank1975]

I've understood it to be more about expansion and contraction with temperature. I was told nitrogen is more stable pressure wise with temp variations. So for TPMS sensors your less likely to trigger a light with fluctuations. Here is a popular science story on it. I just learned that it's obviously drier and doesn't have o2 so there isn't moisture related expansion also and less corrosion.

http://www.popularmechanics.com/cars/how-to/a3894/4302788/

[Bob]

I put a small inline desiccant dryer on the compressor for wheeling. No worries even if it happens to be humid when airing up.

[Chris]

I was reading a Service Station Owner magazine a while back and it was all about the advantages of nitrogen system for commercial use. It showed that by switching to nitrogen allows for the elimination of compressors in a shop. Apparently it's less expensive, quiet and more efficient. In other words it offers more to service providers than the end user and they can make it out as beneficial to the end user - us. Afterall, who doesn't like a green valve cap!

[Spieg]

Hmm. Never thought about the atom size/stability, I'd always assumed the benefit was less oxidation (dry-rot) of the rubber.

[ExplorerTom]

To get the most benefit out of running nitrogen, you need 2 valve stems in each wheel so you can bleed out the regular air trapped in the tire.

[dieseldoc]

This is about expation/contraction
The TPMS that are in Most cars now days are less apt to cause a light with nitro in the tire.
But this is back to the masses not keeping up on the condition of there vehical.
As well as the MPG mandates that are crap.

[newracer]

My tires typically have co2 in them.

[Patrolman]

I was curious as to how CO2 in a tire compares to air or nitrogen. Better? Worse? Not that it really makes a huge difference in the 4x4 crowd.

Regarding the TPMS and pressure fluctuations, I suppose that I could understand that. None of our cars have a TPMS, and none of our cars race at the track, so air it is for us!

[dieseldoc]

Comes down to what you drive.
4x croud gets co2 as we like the tanks that we use for filling tires after a good trail run.
Then again many of us use a onboard compressor so it's not realy something we would use.

I can understand why a guy with an expensive sports car would use nitro but for guys who air down its a waist.

[The StRanger]

I think nitrogen is better, but unless you are racing not worth the hastle.
on my rig, I air down and up often so zero benefit there.

Same here.

[dscowell]

nitrogen made them less likely to lose air because the molecules/atoms are larger than what would be found in compressed air.

Nitrogen has a 14g/mol Molecular weight. Nitrogen isn't found in nature as just a single atom in the air its N2 which would have a 28g/mol molecular weight. The average molecular weight of air is 29g/mol and Oxygen also found in nature as O2 has a weight of 32g/mol. Carbon Dioxide is 44g/mol The molecule size argument doesn't hold much weight:D.

What's going to make a difference is energy change due to change in temperature. Nitrogen may not be as effected by changes in temperature as other gases but that's not something I know.

[Swank1975]

That's it I'm getting Helium. LOL


Nitrogen has a 14g/mol Molecular weight. Nitrogen isn't found in nature as just a single atom in the air its N2 which would have a 28g/mol molecular weight. The average molecular weight of air is 29g/mol and Oxygen also found in nature as O2 has a weight of 32g/mol. Carbon Dioxide is 44g/mol The molecule size argument doesn't hold much weight:D.

What's going to make a difference is energy change due to change in temperature. Nitrogen may not be as effected by changes in temperature as other gases but that's not something I know.

[flashboiler]

Decent read:

https://www.mojotiretools.com/N2_for_tires_FAQ.htm

[Jim]

Decent read:

https://www.mojotiretools.com/N2_for_tires_FAQ.htm

I went straight for the cliff notes section of that FAQ: ;)
https://www.mojotiretools.com/N2_FAQ_Q11.htm