Nitrogen in Tires

[tumbleweed]

Originally Posted by qbee42

How about uranium hexafluoride for better traction?

Tom

But I think you might need rims made from nickel and I'm not sure what you could make the tires out of. UF6 corrodes just about everything doesn't it? But I do have a calcium chloride solution for weight in the rear tires of my old tractor, of course it only has a top speed of 15 MPH.

[richard schumacher]

If O2 did diffuse through tires faster than N2, after a few refills with plain old compressed air the tire would contain mostly dry N2 anyway. It's a complete waste of money to pay for a nitrogen fill. Just check your tires more frequently and you'll get more benefit.

[fuzzy1]

If O2 did diffuse through tires faster than N2, after a few refills with plain old compressed air the tire would contain mostly dry N2 anyway...

What would make it dry?

[qbee42]

Originally Posted by alfon

I have nitriogen in our Michelin Energy Saver AS tires from Costco. Nitrogen molecules have less tendency to leak out of a tire than normal air pressured tires because the Nitrogen molecules are bigger.

At least that is what Costco Tire Techs told me.

Alfon

No, that is just plain silly. The diffusion rate of nitrogen is pretty much the same as air. Air is almost all nitrogen and oxygen, which both have about the same rate of diffusion. The small amount of other gases are too small to have much influence, but if they did, they would diffuse out and we would automatically have "nitronized" tires in short order.

It amazes me that tire stores can get away with outright lying.

Originally Posted by carz89

The molecules aren't "leaking" out in the traditional sense. They are permeating through the rubber (microscopic pores in between the spaghetti network of polymer chains). Oxygen permeates faster then Nitrogen through rubber.

No, not correct. Oxygen molecules are slightly larger than nitrogen molecules. As you might expect, because of this the diffusion rate of oxygen is slightly lower than that of nitrogen. Even so, it's a trifling difference.

Tom

[Gen 3 for me]

My dealer adds nitrogen for free before delivery. I do not want nitrogen because I am concerned about the slight possibility of the tire bead changing position on the wheel rim when the dealer deflates to get the air out.

At the auto assy plant I worked at we used an expensive machine to load the tire wheel assembly to seat the tire bead properly after mounting was finished. This was to get a more accurate balance on the assembly. I do not know whether or not Toyota uses this technology but I would think they do. Otherwise the nitrogen won't hurt and it is no substitute for regular tire pressure checks.

I like the idea that when I do high speed driving that air expands more than nitrogen causing more pressure increase than nitrogen would. So I prefer air over nitrogen irregardless of cost.

[qbee42]

Originally Posted by Gen 3 for me

<snip>

I like the idea that when I do high speed driving that air expands more than nitrogen causing more pressure increase than nitrogen would. So I prefer air over nitrogen irregardless of cost.

This is simply not true. Nitrogen behaves like any other ideal gas. The expansion rate of nitrogen and air are identical for all normal temperatures and pressures.

Tom

[dogfriend]

What about Hydrogen? I want to make my tires lighter. I think I will use Hydrogen.

[carz89]

Originally Posted by qbee42

No, not correct. Oxygen molecules are slightly larger than nitrogen molecules. As you might expect, because of this the diffusion rate of oxygen is slightly lower than that of nitrogen. Even so, it's a trifling difference.
Tom

We agree to disagree. All of the sources on the internet I found claim that Oxygen molecules are slightly smaller than nitrogen molecules. Thus the diffusion or permeation of oxygen is actually higher than that of nitrogen. Rather than quote all of the sources, just look up the covalent radii of each molecule in wikipedia, which is not perfect but generally accurate in these types of articles. If they are all incorrect, please feel free to correct the wikipedia articles yourself.

Oxygen - Wikipedia, the free encyclopedia

Oxygen

Nitrogen - Wikipedia, the free encyclopedia

Nitrogen

The trifling difference in rate of pressure loss is mostly due to the fact that the "air tire" starts out with 80% nitrogen, so that it really isn't much different than 100% nitrogen.

If you compared a 100% oxygen-filled tire vs. a 100% nitrogen-filled tire, you would see a noticeable difference in the rate of depressurization.

[GreenWithEnvy]

You guys (and maybe gals I didn't really check) are just FREAKS. I mean that in the best way, honestly.

[dogfriend]

Wouldn't 100% Nitrogen actually diffuse through the tire more quickly?

Fick's law of diffusion - Wikipedia, the free encyclopedia

If you have 100% Nitrogen inside the tire and 79% Nitrogen (Air) outside the tire, then you have a concentration gradient from higher Nitrogen concentration inside the tire and lower concentration outside tire.

If you have 79% Nitrogen inside the tire and 79% Nitrogen outside the tire, then you do not have a concentration gradient.

Think about that for a minute.