Nitrogen for tires

[dwightdi]

PV = nRT This thread is subject to massive thread wander. Amusing, but not scientific. Race car logic is the same. Lots of unproven theories and urban legends. Since tires are usually just filled with nitrogen, rather that 100% purged of all oxygen (a physical impossibility), the possibility of having a tire filled with only nitrogen is extremely remote. The potential benefit is also infinitesimally small. Interesting waste of time and money.

[jadatis]

Me , who call myself tire-pressure-specialist now, also now concentrating on Nitrogen filling.
Planning to make an article in wich I first sum up all the comercial arguments, then de-mith them or relativate them .

One thing i can already de-mith and that is Nitrogen ( further N2 ) absorbing more heat then Oxigen( O2) , so your temperature and by that pressure stays more constant, for instance when braking .
It is true if you use per mass so per lbs , but as is used in tires in volume , even O2 absorbes ( 1% ) more energy . So this mith can even be deforced because its simply not true.

Busy now on the argument of rubber having little holes in it troug wich the smaller O2 molecule disapears quicker then larger N2 molecule.
But what then at higher pressure ,do the holes get larger so N2 goes yust as fast trough them ?
To my conclusion difusion trough the rubber is a much more complicated matter , somewhere between Phisical and Chemical, so the more reactive the molecule the quicker diffusion.
Then it could be that Helium ( He) althoug its a smaller molecule but totaly inert gas , could even diffuse slower then N2 troug the rubber.
Also Argon is an Inert gas and saw someone mention it here already.
Could be that Argon even dont diffuse at all , and its a side-product of Amonia production , wich is used for artificial vertiliser production, so probably in the same price as Nitrogen.

The rate of diffusion is sayd to 2 or 3 times more for O2 then N2. Even 5 times is mentioned, and I use that in spreadsheet I made. Then this results in less then 2 times more pressure loss for a 80/20 filled tire then a 100/0 N2/O2 division. Then in about a year I think the 80/20 tire looses 10% of its pressure and the 100/0 filled tire "only" 5,8%. Before that you have already checked it tree times if you are wise and filled that small difference of 1/3 th of 6,5 psi on a 65 psi filled tire . The N2 then only looses 3,5 psi in that year .

Filled in my spreadsheet with Argon 98% rest O2 and N2 and asuming argon diffuses 0.1 times as fast as N2 , and then even pressure rises about les then 1 psi , because O2 and N2 diffuse into the tire so more gas is coming into tire in time.

To determine the diffusion factor in compare to N2 ( =1, O2 = probably 5) I thougt out a test with 4 old the same tires with same rimms ( from old car or winter tires when summer) . give them a basic filling empty tire so Zero pressure = 1013 milibar real pressure , with same gas compound as outside
Then fill up with 100% each tire , one N2 two O2 , 3 Helium, 4 ARgon,
then the pressure loss is totally because of the diffusion of that filled gas , because the ground filling is Partial pressure of N2, O2, AR the same as outside , so yust as much of those gasses diffuse in as out.
The diffusion factor then can be calculated yust by deviding the pressure losses.

This would make the diffusion factors for shure and no gambling about it.
My expectation is that it will prove Ar and He to have a diffusion factor of 0,1 or less.

Then last about Water in the tire, my idea is that a little liquid water can help cool down and transport the energy better then dry air.
This because of the energy that is needed to go from liquid to gas ,
The pressure in tire will rise a little wich then gives lesser deflection so lesser heat production by the bending of the rubber.
but first I have to know how to calculate with that, so placed a topic on Dutch science forum about it, but had also to do with partial pressure of water as gas for a sertain temperature before it condenses.

[AFUser]

If air has a greater coefficient of expansion than N then from an economic aspect maybe air really would be better than N? Think hot air balloons. If air in tires gets hotter than N then it would try to rise and so take weight off the trailer which would equal less fuel consumption and less wear on the tires.

The possibilities are boundless. Instead of conventional insulation between the inner and outer skins, how about using balloons filled with helium? And all that wasted space in the chassis box girders. If one got too much lift could traction problems arise? Once when I was working a job I didn't like, the air and everything else seemed heavier on Mondays. So should Mondays be a stationary day?

There's a multimillion dollar government research grant somewhere in here guys.

[K9CarCrate]

This is really a chemistry question. The molecular size of nitrogen remains relatively the same under increased pressure and heat vs. Oxygen. Nitrogen is a smaller molecule. It can make a slight difference if you generally drive 200+ miles per hour. I have never seen a service station that has a system that effectively evacuates all water and oxygen prior to filling a tire with nitrogen. For regular everyday driving, it is a gimmick. Steve

[AFUser]

Originally Posted by dwightdi

PV = nRT This thread is subject to massive thread wander. Amusing, but not scientific. Race car logic is the same. Lots of unproven theories and urban legends. Since tires are usually just filled with nitrogen, rather that 100% purged of all oxygen (a physical impossibility), the possibility of having a tire filled with only nitrogen is extremely remote. The potential benefit is also infinitesimally small. Interesting waste of time and money.

Now look here Dwight. You should know that Airstream owners consider any discussion of Airstreams a serious matter and it could be that some may consider calling their discussion of N "amusing" somewhat of an affront.

[Rich W]

Originally Posted by GCinSC2

Na zdrovyeh.

An attempt at Nastrovia! The Polish version of Cheers! In honor of my Polish better half. But it might not be Polish, we might find out.

Na Zdorovie is a Russian toast. We always say Sto Lat! It's a Polish toast / song for all happy occasions. May you live 100 years; bottoms up! . I'm half Polish, not sure which half, left / right / top / bottom. So far it hasn't mattered much

[GCinSC2]

I toast corrected, only married a Pole. Her nickname is "Ski"

[jadatis]

Originally Posted by GCinSC2

I toast corrected, only married a Pole. Her nickname is "Ski"

If she is a she would her nickname rather be "Ska"

But In my last ( and first) post in this topic, I mentioned that the difusion rate in my test, could simply be determined by deviding the pressure losses , but that is not true.
Have found a way to calculate it thoug, so my test can be done still.
Tried it out that calculation and if for instance 100% N2 filling to empty tire looses 10% and 100 O2 filling 50% in that same time, it calculates not 5 times, but 6 to 7 times that O2 diffuses quicker then N2.

If in a few years Nitrogen is replaced by Argon, then remember it was my idea.
Argon though is a "heavy gas", also used in Air-bags, light bulbs.
So it would make the vehicle a bit heavyer wich we cant use ( about max 1lbs) so this would give Helium an advantage wich makes the vehicle about 2 lbs lighter.

[Gene]

Argon is used in low-e window glass and if the windows are shipped over high mountain passes too fast, the seals don't have time to adjust to the lesser air pressure and weaken and eventually fail. Those of us who live in Colorado check to see where the product is shipped from so they don't come over high passes more than 8,000'. If they do, follow the truck and make him stop every once in a while to allow the seals to adjust—lots of luck with that.

With argon in the tires, you'll have to stop at 8,000', wait a while, go up another one or two thousand, stop again, and so on. Enjoy the beautiful sights, have lunch or take a nap.

Gene

[jadatis]

Tires are not that rigid as window glass , so the tire yust has higher pressure then wich it can stand easyly.

Would the same problemm be if the low-E window was filled with any kind of gas?

[Gene]

Originally Posted by jadatis

Tires are not that rigid as window glass , so the tire yust has higher pressure then wich it can stand easyly.

Would the same problemm be if the low-E window was filled with any kind of gas?

Just like window seals, tires are made of rubber or ersatz rubber, so, absent any kind of logic, argon will leak. You can run a wire from the electric brakes to the argon and it will glow violet, so you can see it leaking when you step on the brakes. It is important you not think this through, because if you do, you will get a different and perhaps correct answer.

Gene

[jadatis]

Then again does Argon leak because its Argon , and dont Nitrogen or Oxigen or whatever other gas leak in the same conditions.

So would this be a reason not to fill your tires with Argon.

[Gene]

Perhaps the answer is here: "Avogadro's law states that, 'equal volumes of all gases, at the same temperature and pressure, have the same number of molecules'".

I don't know what this really means, but it sounds cool. Avogadro's is also the name of a pizza place in Ft. Collins, Colorado, but that has nothing to do with tires. In fact, a lot of the posts on this thread have little to do with anything.

I have a tank with some helium in it, left over from filling balloons. Other than breathing it in so I can have a squeaky voice, I have no need for it. So maybe I'll fill my tires with it and lighten the load.

Jadatis, despite the language differences, you may have noticed by now I'm making things up as I write. Anyone with a photo of Marilyn Monroe in a potato sack as his simulacrum cannot be trusted.

Gene

[gypsydad]

I have both Nitrogen and Air in my tires...think I'll have another Canadian whisky on the rocks and ponder these questions while watching the sun go down....

[jadatis]

Originally Posted by Gene

Perhaps the answer is here: "Avogadro's law states that, 'equal volumes of all gases, at the same temperature and pressure, have the same number of molecules'".

I don't know what this really means, but it sounds cool. Avogadro's is also the name of a pizza place in Ft. Collins, Colorado, but that has nothing to do with tires. In fact, a lot of the posts on this thread have little to do with anything.

I have a tank with some helium in it, left over from filling balloons. Other than breathing it in so I can have a squeaky voice, I have no need for it. So maybe I'll fill my tires with it and lighten the load.

Jadatis, despite the language differences, you may have noticed by now I'm making things up as I write. Anyone with a photo of Marilyn Monroe in a potato sack as his simulacrum cannot be trusted.

Gene

I suspected it , but because of the language difference , first tougth it was a serious subject.
But again, if in a few years Argon filling instead of Nitrogen filling is done for tires , then remember I was the first who suggested it seriously.

[K9CarCrate]

Originally Posted by jadatis

If she is a she would her nickname rather be "Ska"

But In my last ( and first) post in this topic, I mentioned that the difusion rate in my test, could simply be determined by deviding the pressure losses , but that is not true.
Have found a way to calculate it thoug, so my test can be done still.
Tried it out that calculation and if for instance 100% N2 filling to empty tire looses 10% and 100 O2 filling 50% in that same time, it calculates not 5 times, but 6 to 7 times that O2 diffuses quicker then N2.

If in a few years Nitrogen is replaced by Argon, then remember it was my idea.
Argon though is a "heavy gas", also used in Air-bags, light bulbs.
So it would make the vehicle a bit heavyer wich we cant use ( about max 1lbs) so this would give Helium an advantage wich makes the vehicle about 2 lbs lighter.

There's a little problem with Argon. Argon has an incredible insulation property. That's why they use it in windows too. When I drysuit dive in the winter, I fill my drysuit space with Argon gas. It is so insulating from the cold water, it feels like I just peed in the suit. It reflects my body back onto me and makes winter diving very enjoyable. I can imagine that the heat insulation if the tire was filled with Argon would be incredible. It's amazing how just a few extra electron, protons, and neutrons can make such a difference! Steve.

[aftermath]

I continue to hear that the Navy uses Nitrogen in their jet tires. There are all sorts of reasons to do this and I won't disagree. When I get to the point where I can do a carrier landing from 30K ft in my Airstream, I might seriously look into this.

[featherbedder]

Originally Posted by gypsydad

I have both Nitrogen and Air in my tires...think I'll have another Canadian whisky on the rocks and ponder these questions while watching the sun go down....

If you have both air & n2 in same tire n2 is useless as it is contaminated.

[jadatis]

Originally Posted by K9CarCrate

There's a little problem with Argon. Argon has an incredible insulation property. That's why they use it in windows too. When I drysuit dive in the winter, I fill my drysuit space with Argon gas. It is so insulating from the cold water, it feels like I just peed in the suit. It reflects my body back onto me and makes winter diving very enjoyable. I can imagine that the heat insulation if the tire was filled with Argon would be incredible. It's amazing how just a few extra electron, protons, and neutrons can make such a difference! Steve.

There you have a point, searched it and found 15 Joule/mol/degr Kelvin, and Air about 20 J/m/dgrK so thats a substantial difference. Then it was for as is needed in tires when vollume stays constant.
And the transportation of heat inside the tire would better be more then less, to cool down the rubber at higher speed.

Still trying to find out how much energy water needs to go from liquid to gas, but dont think it will compensate that loss with Argon.
Would get a complex mix of Argon and liquid water and a basis of normal air , so I think we have to forget Argon.
Would mean that your tires stay at constant pressure ( cold) for years , but your tires get damaged because sertain spots ( or rings) get damaged by the heat they produce and ar not cooled down enaugh.

[CapriRacer]

Originally Posted by jadatis

There you have a point, searched it and found 15 Joule/mol/degr Kelvin, and Air about 20 J/m/dgrK so thats a substantial difference. Then it was for as is needed in tires when vollume stays constant.......

You will want to be careful here. The specific heat capacity of a gas changes how RAPIDLY the temperature builds up, not what temperature the gas eventually gets to. This difference might be useful for situations where speeding up or slowing down the temperature change is advantageous ((like a Formula 1 race), but in street tires, it hardly matters. Whether it take 45 minutes or an hour to reach a stable temperature, it still reaches the same stable temperature.