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Old 3rd February 2009, 09:52   #316
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Folks Nitrogen has a molecular weight of 28 and oxygen is 32. In other words the Oxygen in the air is a heavier molecule and should diffuse out slower.

As very rightly stated the laws of Physics give be zilch for nitrogen.

Nitrogen is used in aircraft and F1 primarily becuse of slightly better conductivity. If you have dry air (this may not be there at a fuel pump/service station due to close proximity of washing apparatus) then there should be no difference. I use a small electric/foot pump at home and have no problem. Quite often the improvement you see is because of uniform and full pressure.
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Old 3rd February 2009, 10:57   #317
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Relax folks all of us fill 78% pure nitrogen and some of us spend more money and get the percentage to may be 90%. Those who are not in coastal areas any way get the dry 78% nitrogen.


But Nitrogen filling has an important role to play that is to give a decent living to the Tyre guys and their families.

Last edited by amitk26 : 3rd February 2009 at 11:03.
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Old 3rd February 2009, 12:50   #318
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Quote:
Originally Posted by Nikhilb2008 View Post
Why does Nissan fill Nitrogen in the GTR then?

If as you 'experts' say Nitrogen has NO effect whatsoever, why does Nissan fill Nitrogen?

Why is it that most racing cars (f1 included) used Nitrogen? Why is it that today F1 doesnt use dry compressed air, but some special gas?
The reason why Nitrogen is used is because it is closest to the normal air that we breathe.
It is non toxic, inert, slightly lighter than air.

I guess whatever advantages the customers are facing - might be mainly due to less moisture.

Nitrogen under NO circumstances can diffuse LESS than air (which is a mix of nitrogen and oxygen)

Probably the leaking of air from tyres is attributable to microscopic oxidation of valve/lining.
Pure nitrogen being inert will not allow that.
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Old 3rd February 2009, 12:56   #319
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Quote:
Originally Posted by Mindgrinder View Post
What all places in bangalore?
One was observed at HP petrol Pump Near Cosmos Mall, Brookfields, Kundalahalli, Marathahalli.

Need to figure out other places , if they are any !
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Old 3rd February 2009, 15:17   #320
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Quote:
Originally Posted by lambuhere1 View Post
One was observed at HP petrol Pump Near Cosmos Mall, Brookfields, Kundalahalli, Marathahalli.

Need to figure out other places , if they are any !

There is one at HP pump on the old airport road next to pizza hut
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Old 3rd February 2009, 20:57   #321
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Quote:
Originally Posted by alpha1 View Post

Nitrogen under NO circumstances can diffuse LESS than air (which is a mix of nitrogen and oxygen)
Nitrogen molecules are bigger.
So loss of air pressure over time is lesser.
As for expansion, nitrogen expands lesser than normal air when tires get heated, but to get the actual "benefits" such they really make a significant difference, you have to be ripping the car on a racetrack. In normal usage, nitrogen won't make a very significant difference. Therefore its worth it if you can get it for free.
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Old 3rd February 2009, 21:20   #322
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Quote:
Originally Posted by tsk1979 View Post
Nitrogen molecules are bigger.
So loss of air pressure over time is lesser.
As for expansion, nitrogen expands lesser than normal air
Sorry, that is not quite correct.
Normal compressed air is in any case 78% Nitrogen. And because there's almost 20% oxygen, higher molecular weight, there will be less tendency for porosity leakages.
There is no reason for Nitrogen to expand any less than DRY compressed air. Both will follow the Gas Laws.
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Old 3rd February 2009, 22:14   #323
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After umpteen number of experiments done with the help of the TPMS system on my car I have found that nitrogen expands as much as normal compressed air and runs pretty much the same temperatures.

Some results below. Please note that the ambient air temperature was within +/- 2 deg C on all the test days. This was checked using a old school mercury thermometer.

Compressed air at 7:00am on January 2nd - pressure = 27.6psi, temperature inside tyre = 20 deg C
Nitrogen at 7:00am on January 8th - pressure = 27.8psi, temperature inside tyre = 21 deg C.

Compressed air at 10:15am on January 2nd after normal city driving for 30kms to office - pressure = 31.6psi, temperature inside tyre = 42 deg C.
Nitrogen at 10:20am on January 8th after normal city driving for 30kms to office - pressure = 31.2 psi, temperature inside tyre = 41 deg C.

Compressed air at 6:15pm on January 2nd after vehicle being parked under shade the whole day - pressure = 28.2psi, temperature inside tyre 26 deg C.
Nitrogen at 6:15pm on January 8th after vehicle being parked under shade the whole day - pressure = 28.4psi, temperature inside tyre = 25 deg C

Compressed air at 7:30pm on January 2nd after normal city driving for 30kms back from office - pressure = 31.4psi, temperature inside tyre = 41 deg C.
Nitrogen at 7:40pm on January 8th after normal city driving for 30kms back from office - pressure = 31.6 psi, temperature inside tyre = 42 deg C.

I have tons of such data and have tried air and nitrogen from all the bunks and tyre shops that I frequent.

My conclusion: It does not matter at all whether I run nitrogen or air. The conditions inside the tyre are more or less the same. Even after heavy track driving the conditions are within 5% of each other. The temperature inside the tyres has touched 65 deg C after heavy track driving.

Also spoke to the company representative of Bhoruka Gases. They are the people who supply industrial gases to my company. According to him the commercial quality cylinders that the tyre shops use will contain anywhere from 5 - 15% moisture in them. He also rubbished the fact that people claim that nitrogen molecules are bigger.

Edit: Even after highway driving of 300+ kms the pressure & temperature difference between air & nitrogen is within 4% of each other. Also please note this is not to deter people from using nitrogen. Use it if you want to. But I have found no difference between the two.

Last edited by vikram_d : 3rd February 2009 at 22:18.
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Old 3rd February 2009, 22:20   #324
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Quote:
Originally Posted by vikram_d View Post
After umpteen number of experiments done with the help of the TPMS system on my car
Vikram, which car is this? Scorpio mHawk?
If yes, aren't you running with pressure on the lower side? Perhaps that's why you could measure 65 celsius.
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Old 3rd February 2009, 22:25   #325
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I drive a Swift ZXi with an aftermarket Xenos make TPMS. The cold tyre pressure that I maintain is 28psi. Also there are no limits for temperature. It will show what ever is there inside the tyre. It has high & low limit alarms for pressure though. The alarms are in 3 levels +/- 12%, +/- 25% and +/- 50%.

During the track session the system sounded the 12 & 25% alarms for high pressure. Now I start my track sessions with 22psi in the tyres. And still it goes up to 32 - 33 psi after 4 - 5 laps.

Last edited by vikram_d : 3rd February 2009 at 22:27.
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Old 3rd February 2009, 22:40   #326
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From what I have read, talked about with proffesors and seen in real life. Nitrogen is best left for uses where even a 1% difference makes major differences. (F1, Moto GP)

I wont use Nitrogen in everyday use unless it is free.
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Old 3rd February 2009, 22:47   #327
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Hi Guys,
Filled Nitrogen in my Swift Zxi Michelin XM1+ tyres yesterday at Mastakar Pump (Andheri - West). Cost was Rs. 100/= and valid for refills for 3 months. You get a card which you keep in the car. After the initial 3 month period you pay Rs. 60/= and it is then valid for another 3 months.
All the (old) air was sucked out of the tyres using a vacuum pump and then the N2 was filled in. I have to say that i noticed an immediate difference in the ride quality which is much softer (and more comfortable) now. swift owners will know what I mean.
For all the money we spend on our vehicles I think Rs. 100/= for a more comfortable ride is well worth it.
I will be doing my Wagon R tomorrow.

Cya.
SS
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Old 4th February 2009, 09:29   #328
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Quote:
Originally Posted by vikram_d View Post
Now I start my track sessions with 22psi in the tyres. And still it goes up to 32 - 33 psi after 4 - 5 laps.
Vikram, what I meant was: Have you tried starting with pressure 30 psi (or whatever is the recommended pressure for the Swift), instead of 22 psi? Does the pressure still increase rapidly?
Is this increase happening because of tyre sidewall flexing or very frequent use of brakes?
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Old 4th February 2009, 10:00   #329
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I got Nitrogen filled into my OHC in Oct 2008 when I drove from Mumbai to B'lore & back. I covered 1100 kms (home to home, oneway) in 13 Hrs and at some streaches doing about 140 km/h for upto 10 minutes. I could experience better handling, it felt as though the car was gliding, the braking was better than the usual, I got an average FE of 17km/L. I haven't had to refill it yet and the tyre pressure looks good.

And yes, I got this filled at a fuel pump before I entered Pune and was left with Rs.200 lesser in the pocket.
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Old 4th February 2009, 10:50   #330
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Gosh, placebo really works!
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