Somebody educate me on "Nitrogen" in the tires ?

jplante4 wrote:
Mine had helium and the GVW was 1000 pounds more than a stock Sahara.

Never thought to weigh my truck after adding helium.......

but now I never need to slow for speed bumps in the parking lots,

just "glide" over pot holes in the road, steering is easier, and

the kids in the neighborhood love it when I fill balloons from my tires!

:C

Even if Oxigen diffuses trough the rubber 5 times as much as Nitrogen,the pressure loss is in the beginning only less then 2 times as much.
The longer it lasts the more the partial pressure of oxigen comes closer to that of the outside air, and the advantage is less.
And , What I read is that oxigen only diffuses about 3 times as fast as Nitrogen, so difference is less already in the beginning.

The reason why they began with Nitrogen filling is that its was easyer on the road , better then a portable compressor.
Nitrogen is the cheapest gas that is delivered in cylinders.
Its a wasteproduct of the Amoniak- production, wich on its turn is used for artifical furtiliser.

if you manage to fill the tire with 100% Nitrogen , the partial pressure of Oxigen is zero bar/psi or whatever, the outside partial pressure of oxigen is constant 21% of 1 barr/ 14.7 psi.
so then the oxigen difuses into the tire , against the higher total pressure in the tire.
Most wont beleve this , but search for the Law of Dalton for that.
Says about that every gas behaves , for instance for diffusion, as if it was the only gass in the space.

So in the beginning after filling to 100% Nitrogen, wich is not possible, the loss of Nitrogen is a bit compensated by the oxigen goin into the tire.

FrankShore wrote:
The molecule of Nitrogen is larger than that of oxygen, thus the nitrogen will not leak out as early or as often.

To the people who say: Gimmick, these are basic facts, the nitrogen leaks out much slower due to it being a larger molecule

Again, the testing I've seen, or was part of showed less than 3psi difference after a year on high pressure tires over 200psi, consumer reports testing on tires inflated to 30 psi showed a difference of 1.3 psi comparing tires inflated to with air as compared to purged and strictly nitrogen filled tires after a time period of 1 year. I wouldn't call that much slower as it's such a slight difference you need a large sample size and tightly controlled temperature and measuring equipment to even see it. I get a lot more pressure variation than that just from the normal temperature variation over the course of a day. Being as how I re-set my tire pressure several times over the course of the year based on temperature changes, and sometimes location/altitude changes I can't see where any benefit could be realized. I'll stick with my vote for gimmick.

Shoot, we had tires on our tricycles that never needed air after sitting for years.

westend wrote:

FrankShore wrote:
The molecule of Nitrogen is larger than that of oxygen, thus the nitrogen will not leak out as early or as often.

To the people who say: Gimmick, these are basic facts, the nitrogen leaks out much slower due to it being a larger molecule

How much slower does the nitrogen tire deflate compared to one filled with air?

I have 50 YO tires on one of my orchard trailers that are still up and ready to roll. Haven't been fill with "air" in over 50 years!

YMMV!

FrankShore wrote:
The molecule of Nitrogen is larger than that of oxygen, thus the nitrogen will not leak out as early or as often.

To the people who say: Gimmick, these are basic facts, the nitrogen leaks out much slower due to it being a larger molecule

How much slower does the nitrogen tire deflate compared to one filled with air?

The molecule of Nitrogen is larger than that of oxygen, thus the nitrogen will not leak out as early or as often.

To the people who say: Gimmick, these are basic facts, the nitrogen leaks out much slower due to it being a larger molecule

In the aviation industry, we would get some training on this issue from time to time, both theory and practical. Primary reason for Nitrogen in aircraft tires is because the nitrogen we purchase is moisture free, often from liquid nitrogen carts depending on where you're working. We maintain nitrogen servicing equipment anyway for servicing struts, accumulators etc because of the moisture free aspects, and because it's and inert gas that won't cause corrosion on internal components. It only makes sense to use dual purpose equipment to service those items and the tires being as how it's expensive to use compressors with quality moisture removing capability.

As for tires leaking down slower etc. all the studies I've seen showed the theory didn't really pan out in the real world, and even after a high pressure tires were left sitting a year without being touched the difference when compared with standard air fill tires was only a couple PSI, virtually insignificant. I haven't seen any studies where it made any difference in tire life, but in theory it regular air could lead to corrosion of the wheel more than you would get with pure nitrogen. Other than tires filled with the liquid seal stuff I've never really heard of wheels corroding out internally.

safeman wrote:
I keep a precise mixture of 78 percent nitrogen in all my tires:B

Me too, wouldn't have it any other way. Even my Mowers.