Nitrogen in Tires?

[powerboatr]

yes, oil free dry pumped nitrogen is the stuff
we had a warm spell this morning its back into teh 60's for today

 

[95_stroker]

The fact that it has no moisture in it must be why it does not lose pressure during cold temperatures.

No, I believe that would be based upon the fact that N2 is an inert gas.

 

[whatabudro]

its what all nascar teams use also.

 

[powerboatr]

somebody just had to say "nascar"


it hasnt been worth watching since dale was lost.

 

[NVCowboy]

Offroad Desert Race Vehicles have been using nitrogen for years now. Dont remember any other benefits other than the ones mentioned.

 

[BJS]

No, I believe that would be based upon the fact that N2 is an inert gas.

Technically not an intert gas but it exists as a diatomic molecule meaning that they are alwasy 2 nitrogen atoms attached together. it is farily unreactive though given the proper environment will react.

The fact that it is a very stable diatmoic moleclue is what contributes to it's ablity to stay in tires and at lower temperatures. The diatomic molecule of nitrogen is an eliptical molecule with a dimensions of aproximately 3Å. While you have other components in the atmostphere that have a larger diameter (CO2 notably) but are in such a small level. (see chart below)

PERMANENT gases in the atmosphere by percent are:

Nitrogen 78.1%
Oxygen 20.9%

(Note that these two permanent gases together comprise 99% of the atmosphere)

Other permanent gases:

Argon 0.9%
Neon 0.002%
Helium 0.0005%
Krypton 0.0001%
Hydrogen 0.00005%

VARIABLE gases in the atmosphere and typical percentage values are:

Water vapor 0 to 4%
Carbon Dioxide 0.035%
Methane 0.0002%
Ozone 0.000004%

Crumm you are seeing the tires deflate because the rubber and steel are contracting away from each other @ the bead seat as well as the physical structure of the rubber begins to pull away from itself at very cold temperatures allowing for larger (read very super small) pores to develop in there tires.

Because oxygen when in diatomic for will react with other elements in the atmosphere it when exposed through these microscopic pores thereby reducing the one molecule at a time what is in the tire. it will alwasy move out of the tire due to the natural tendency to move to lower energy states (lower pressure)

Nitrogen due to the nonreactive nature in it's diatomic state will reduce or depending on size of the microscopic pores in the tires possibly eliminate this seepage.

Back again to the ideal gas law as I mentined earlier PV=NRT (units must be SI units)
P=pressure in pascal
V=Volume in cubic meters
N=#of molecules (technically moles)
T=temperature in kelvin (kelvin temp = Celcius + 273)
R= Universal gas Constant

The universal gas constant is defined in terms of Boltzmann's constant k as

where

is Avogadro's number.

In various useful units, the universal gas constant can be written

=

=

=

=

=

Based on ideal gas law calcuations the tire w/ 65 psi @ 70°F will have 53 psi @ -33°F for a tire w/ a volume of 1m^3 (i'm too lazy to actually calcuate the tire volume)


Lazy man's Ideal gas law calculator just leave the desired result blank then click calculate.

 

[powerboatr]

ouch
that was heaavy reading for lunch

Methane 0.0002%
I have a good idea who contributes this MOOOO

 

[Crumm]

Technically not an intert gas but it exists as a diatomic molecule meaning that they are alwasy 2 nitrogen atoms attached together. it is farily unreactive though given the proper environment will react.

The fact that it is a very stable diatmoic moleclue is what contributes to it's ablity to stay in tires and at lower temperatures. The diatomic molecule of nitrogen is an eliptical molecule with a dimensions of aproximately 3Å. While you have other components in the atmostphere that have a larger diameter (CO2 notably) but are in such a small level.

Thats what I was thinking I just didn't know how to say it Then again I have no idea what the heck you are talking about but I guess the moral of the story is Nitrogen in tires is a good thing.

 

[DaveBen]

Technically not an intert gas but it exists as a diatomic molecule meaning that they are alwasy 2 nitrogen atoms attached together. it is farily unreactive though given the proper environment will react.

The fact that it is a very stable diatmoic moleclue is what contributes to it's ablity to stay in tires and at lower temperatures. The diatomic molecule of nitrogen is an eliptical molecule with a dimensions of aproximately 3Å. While you have other components in the atmostphere that have a larger diameter (CO2 notably) but are in such a small level. (see chart below)




Crumm you are seeing the tires deflate because the rubber and steel are contracting away from each other @ the bead seat as well as the physical structure of the rubber begins to pull away from itself at very cold temperatures allowing for larger (read very super small) pores to develop in there tires.

Because oxygen when in diatomic for will react with other elements in the atmosphere it when exposed through these microscopic pores thereby reducing the one molecule at a time what is in the tire. it will alwasy move out of the tire due to the natural tendency to move to lower energy states (lower pressure)

Nitrogen due to the nonreactive nature in it's diatomic state will reduce or depending on size of the microscopic pores in the tires possibly eliminate this seepage.

Back again to the ideal gas law as I mentined earlier PV=NRT (units must be SI units)
P=pressure in pascal
V=Volume in cubic meters
N=#of molecules (technically moles)
T=temperature in kelvin (kelvin temp = Celcius + 273)
R= Universal gas Constant





Based on ideal gas law calcuations the tire w/ 65 psi @ 70°F will have 53 psi @ -33°F for a tire w/ a volume of 1m^3 (i'm too lazy to actually calcuate the tire volume)


Lazy man's Ideal gas law calculator just leave the desired result blank then click calculate.

I thought that someone would come up with a good explanation, using $5.00 words that would completely baffle tha rest of us. Good science and I amtrying to remember back to the '60s when I took chemistry.

Dave

 

[BJS]

I thought that someone would come up with a good explanation, using $5.00 words that would completely baffle tha rest of us. Good science and I amtrying to remember back to the '60s when I took chemistry.

Dave

Yeah I have the benefit that I work in a research lab so $5 & $10 words are used daily. I just had to find the time to actually write the post.

The simplified point is that @ the temp changes Crumm is seeing he's still going to be about 10 psi low when it gets cold so he's going to have to fill the tires no matter what's in them. So if you're paying extra $$ for nitrogen then it's a waste especially if you have a compressor @ home. It's better for the average person who never looks or much less checks the air in their tires because the fluctuation is minimized.