Somebody educate me on "Nitrogen" in the tires ?

[NanciL]

We just bought a new Travel trailer and I never noticed at the dealers, but saw a sticker on the side today that said there is nitrogen in the tires.
Someone please explain what this is for.

Jack L

[ol_Bombero-JC]

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

[jadatis]

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.

[Searching_Ut]

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.

[fj12ryder]

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

[Turtle_n_Peeps]

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!

[FrankShore]

YMMV!

[westend]

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?

[FrankShore]

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

[Searching_Ut]

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.

[Horizon170]

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.

[Ohio_Engineer]

Inflating tires with N2 has a few real and some theoretical advantages. However many of the sales claims are based on the assumption that the vehicle owner never monitors or maintains tire inflation.

The issue come up when facts are considered. Tires inflated with "AIR" have about 78% N2. Under test conditions 3 years later due to normal out-gassing of the O2 and addition of more air a tire will end up with about 82 to 85% N2.

Most shops offering N2 are not using pure bottled N2 but are using a nitrogen separator so are creating a gas that is about 98 - 99% N2. When you inflate a tire with 99% you do not end up with 99 as there is O2 left in the tire originally and even a 3x fill and purge does not remove all the O2 so you end up with about 94-96% N2.

Cost If there was no cost I would say do it but there is a cost both direct payment to dealer and sometimes additional travel time & cost to dealer location.

pay-back Doubtful as MPG is theoretical and probably may not even measurable if all performance characteristics are considered. Tire life may also be doubtful since most RV tires are replaced due to age.

[jadatis]

Did some administrative research on this and next document came from it.

Filling car tires with normal air is better then with Nitrogen.
A. Oxygen, which makes 21% of normal outside air, in volume absorbs more energy to rise a degree in temperature then Nitrogen.
Difference is only 1% , but in selling argument is sometimes mentioned in energy/ mass so Joule/kg.degr. Kelvin and there Nitrogen wins by 13 % . Tires though are filled with a certain volume so that counts .
This selling argument can be de-myth simply by the fact that its untrue.

B. Water in a tire transports the heat more then dry air or Nitrogen-filling ( which is by its production process free of water).
Not for no reason water is used in central heating and cooling system of cars as main substance.
The tire inside will have lower temperature which is better for cooling down the important spots of the tire wich have to keep a low enough temperature to prevent hardening and damage in next bending of those parts.
When incidentally the tire inside gets hotter ( sunshine on tire or severe braking, or high ambient temperature) more water goes over to gas wich highens the pressure inside the tire more then dry gas. Also then more water as gas in tire so even better cooling.
So advantage of water is 2 ways when needed, better cooling and lesser heat production.
Disadvantages of water as oxidation only happen at outside . Tire specialists will confirm that when they remove a tire of the rim , the rim inside the tire is not corroded.

C. When a Truck, transporting flammable substance, is on fire, the little oxygen in a tire will , when exploding ,probably even kill the fire .
In tunnels experiments where done to kill the fire with air current , and it worked, despite the oxygen in it.

D. A normal car tire up to truck tire is not a race-car tire, for which a constant as high as possible contact area, so best grip , is needed to give half a second better round time.
For that reason they are filled with as dry as possible air or Nitrogen.
That this gives low lifetime is not important, and for a normal car tire it is.
Often blowing tires at racing, is seen there as collateral damage, but we don’t want that for normal car tires.

E. A car tire is also not a airplane- tire in which the water can freeze and when landing this can give misbalance , which can lead to tire-failure or accident, when suddenly going from zero to about 200m/h.
The water in a car tire does not freeze that often, and when it does and the car begins do drive , it begins slow and the misbalance is not a big problem . then pretty soon, certainly when on speed the ice is melted to water and problem will be gone.

F. When filled with normal air the user is aware of checking the tires regularly, which takes better care of a saver tire, because regularly filled up to the right pressure and optical checking of the tire .
The illusion that Nitrogen filling makes the tire to loose almost no pressure, which is often exaggerated to 5 times , while in real a poor 2 times and then only in the very beginning, makes the user less caring .
The tire also looses air when hitting pavement so temporary leak between edge of tire and rim, Filling with whatever gas-combination won’t prevent that.
This idea is even stronger when TMPS is used which is often inaccurate , so the user thinks to maintain the right pressure, while really riding with to low pressure for longer time, which can lead to tire damage. Aftermarket sensors for TMPS when screwed on the valve can give leakage trough hole where valve is placed , because of the bending of the valve by centrifugal forces at speed.

G. Filling with normal air is always possible, even with a bicycle- pump, is only to fill up so won’t take that long. When you keep driving with to low pressure , in order to find a place to fill with Nitrogen, you damage your tires. So just fill up with normal outside air, even when the tire is filled with Nitrogen. Then also you don’t need to have the tire refilled with pure Nitrogen by your tire specialist when at home again, not worth the trouble, and normal air is even better then nitrogen because of the water in it.

[manualman]

Bottom line: There is no downside but cost. Don't spend money to get it, but if you got it, don't change anything else about how you care for 'em. Still gotta check pressure and add plain air if low.

[NanciL]

So , now I am educated and wondering why they spent the extra bucks to put Nitrogen in the tires but spent so much less on quality workmanship on the interior of the trailer ?

Thanks every one for the various replies

Jack L