Got Nitrogen (N2)?

[ManyCamaroz]

I noticed one of the guys at work had green valve stem caps on his truck. I asked why and he said that he is runnig nitrogen in his tires and the green valve stems are the identifier. the several day's later I was driving a Cadillac SRX loaner and it had aluminum valve stem caps with green dots on them, I figured them to have notro in them as well.

 

I wondered what kind of benefit is there? I use a great deal of nitogen at work and have a plentiful supply. I guess since it is virtually moisture free it does not expand and contract as much.

 

Any body know of any other benefits?

[99-2door]

http://www.irco.com/pressroom/newsatir/is/58711.html

 

read this it has some info.

 

Now, this might be essential for racing applications, but I don't think it is really that beneficial for normal passenger cars. I could see how it could help on tires with heavy loads on them too since it helps with heat.

 

The big arguement in the page above is nitrogen vs. oxygen.

 

 

Normal air is 78% nitrogen anyway and only 20% oxygen

[budhayes3]

I've known about stock cars using nitrogen to inflate the tires, mainly for consistent and stable tire pressures, but never even considered filling my tires with it. That's actually kind of a neat thought...something to ponder.

[Bill55AZ]

I believe there is better cooling of the tires with pure N2 as compared with air.

Does anyone know the relative heat transfer coefficients of N2 vs. air?

[99GMCZ71]

I had my tires rotated at Costco and when I got it back it had green valve stem caps on it. I doubt they use Nitrogen in the tires.

[Markeaux]

I had my tires rotated at Costco and when I got it back it had green valve stem caps on it. I doubt they use Nitrogen in the tires.

 

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Evidently they do use nitrogen

http://www.google.com/search?sourceid=navc...costco+nitrogen

[ManyCamaroz]

I had my tires rotated at Costco and when I got it back it had green valve stem caps on it. I doubt they use Nitrogen in the tires.

 

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That is where my co-worker gets his tires done and he told me they had Nitrogen in them.

[tmf6902]

SO.....my question is.......and keep in mind I am no Physisist(sp)...but how will that effect the tire pressure as it is read with a normal pressure guage?? Will it?????? do you need a special guage to measure the PSI??? and what happens when you add normal air into the tires because of natural loss?????

[ManyCamaroz]

I had my tires rotated at Costco and when I got it back it had green valve stem caps on it. I doubt they use Nitrogen in the tires.

 

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Evidently they do use nitrogen

http://www.google.com/search?sourceid=navc...costco+nitrogen

 

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They said it was pricey! And it was about $3-$5 bucks a tire. Not exactly, I guess wording like that makes the customer feel he is getting something for nothing. A 300 series (300 c.f.) bottle is charged to 2500 psig and cost about $2.75 delivered. I figure you could pump up about 8 tires off of one bottle.

 

I think I'm going to purge my tires of air and try the nitrogen for research purposes...

[ManyCamaroz]

I had my tires rotated at Costco and when I got it back it had green valve stem caps on it. I doubt they use Nitrogen in the tires.

 

<{POST_SNAPBACK}>

 

 

 

Evidently they do use nitrogen

http://www.google.com/search?sourceid=navc...costco+nitrogen

 

<{POST_SNAPBACK}>

 

 

 

 

They said it was pricey! And it was about $3-$5 bucks a tire. Not exactly, I guess wording like that makes the customer feel he is getting something for nothing. A 300 series (300 c.f.) bottle is charged to 2500 psig and cost about $2.75 delivered. I figure you could pump up about 8 tires off of one bottle.

 

I think I'm going to purge my tires of air and try the nitrogen. For research purposes of course...

 

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[Bill55AZ]

I had my tires rotated at Costco and when I got it back it had green valve stem caps on it. I doubt they use Nitrogen in the tires.

 

<{POST_SNAPBACK}>

 

 

 

 

 

They said it was pricey! And it was about $3-$5 bucks a tire. Not exactly, I guess wording like that makes the customer feel he is getting something for nothing. A 300 series (300 c.f.) bottle is charged to 2500 psig and cost about $2.75 delivered. I figure you could pump up about 8 tires off of one bottle.

 

 

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No charge if you bought the tires at costco.....

[Blue-2001-Z71]

No special gauge required, pressure is pressure. The big huff about using N2 in aircraft is A: No oxygen to feed a brake fire and B: No moisture in the tires to corrode the wheels. You might benefit slightly from the corrosion aspect, and maybe if you take your car on the track regularly, you might notice a differance. But I pulled the OE steel wheels off of my old '82 Chevy and when we dismounted the tires, the rims were perfect underneath. Looked brand new, compared to the rusted out exterior. I wouldn't go out of my way to fill mine with nitrogen, but if that's what your shop uses, great.

 

PS, when they mount the tires, what do you think it starts out being filled with? Answer, ambient air is inside the tire before they seat the bead, so they'll never be 100% pure anyway.

[catmandoo]

What about CO2?

[potz1999]

I believe there is better cooling of the tires with pure N2 as  compared with air.

Does anyone know the relative heat transfer coefficients of N2 vs. air?

 

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Conduction Heat transfer coeffiecents @300K from Incropera and DeWitt:

N2: 0.0259 W/mK

O2: 0.0268 W/mK

Air: 0.0263 W/mK

Not much difference.

[Greg]

I thought I read somewhere that automakers were considering nitrogen because tires don't lose pressure like they do with regular air. This has become more important given the Ford-Firestone debacle and the number of low-profile factory tire-wheel combinations. It may also have been an alternative to the soon-to-be required tire pressure monitors.