Inflating tyres with dry nitrogen

[sn48001]

Air is 78% nitrogen, N2, and 21% oxygen, O2. So even if you put air in the tire, it's already 78% nitrogen. Many of the so called nitrogen generators don't produce much more than 90% nitrogen.

[harsh87]

Originally Posted by pujaari

HP's Hemkund service station just after the Def col flyover(Over looking JLNehru stadium) Mon-sun except saturday. go generally after 10 in the morning till 6 in eve. rs 15(4 wheelers) for all 5 tyres and u could tip the guy when u go for a recheck and Rs 10 for 2 wheelers.
just incase u cant find the station their tel no is:24361301,24361358 (written on the pamphleti got when got tyre niro filled)

some adv written on the pamphlet are:

Low Thermal Conductivity of Ntrogen
Nitro doesnt expand due to heat, therefore in summer or at hih speed, the tyre does not expand or burst due to inc in temp.

Due to high thermal coeff of expansion, nitrogen derives a stable nature. therefore, the gas does not expand due to inc in temp and hence does not exert pressure on internal wall of the tyre. it gives longer life to tyre.

The nitro gas does no contract due to low temp. thus the tyre rubber does not contract. therefore for the life of the tyre rubber increases.

Also as the tyre rubber remains softer( elastic) because of low expansion and contraction, the breaking of tyre is improved due to improved road grip.

Advantages of nitrogen gas

As the elastic property of tyre rubber is intact, the tyre does not skid on turns. the tyre makes less noise on turns.
Usage of nitrogen gas in tyre "increase the tyre life by 20-25% & fuel saving by 6-10%.

Al F1 and racing cars use nitro in tyre for better road grip, driving comfort and safety

Nitro is lighter than air in weight. Usage of nitrogen gas in wheels dec overall weight of the vehicle and hence inc fuel efficiency

The size of nitrogen gas molecules is 4 times bigger than air molecules therefore incase of puncture, the nitrogen gas escapesvery slowly from the tyre thus giving more time to drive a punctured tyre.

the advantages quoted are way too optimistic but aint a bad deal for 15 bucks will try it out soon

[jkdas]

Originally Posted by pujaari

HP's Hemkund service station just after the Def col flyover(Over looking JLNehru stadium) Mon-sun except saturday. go generally after 10 in the morning till 6 in eve. rs 15(4 wheelers) for all 5 tyres and u could tip the guy when u go for a recheck and Rs 10 for 2 wheelers.
just incase u cant find the station their tel no is:24361301,24361358 (written on the pamphleti got when got tyre niro filled)

wow! think its 50rs per or 15rs tyre at Cochin! It cant be 15rs for all 4/5 tyres

[hydrashok]

Originally Posted by jkdas

wow! think its 50rs per or 15rs tyre at Cochin! It cant be 15rs for all 4/5 tyres

It is Rs.50/- per tyre in Kochi/Cochin per tyre for full nitrogen filling (let-out all air, refill completely with Nitrogen). Top-ups are free. (I've topped-up 4-5 times so far. Available only in Global Tyres, near Popular, Mamangalam right now.

[jkdas]

Originally Posted by hydrashok

It is Rs.50/- per tyre in Kochi/Cochin per tyre for full nitrogen filling (let-out all air, refill completely with Nitrogen). Top-ups are free. (I've topped-up 4-5 times so far. Available only in Global Tyres, near Popular, Mamangalam right now.

thanks for confirming. I was with nikkibike when we went for free top-ups. I was sure it was 50 but got confused when I read the other post.

Now, is the 15Rs one and the 50Rs one the same thing?

[sn48001]

At relatively low pressures (ie tyre pressures) N2, O2 and water vapor will all behave as ideal gases, and follow PV=nRT. Pressure will increase or decrease to the same extent as the temperature increases or decreases regardless of which gas is in the tire. (Even at 300 psi, which is about 20 atm, there is little deviation from ideality.) Therefore the comments about N2 not changing in pressure as the temperature changes are without merit.

[vikram_d]

Originally Posted by sn48001

At relatively low pressures (ie tyre pressures) N2, O2 and water vapor will all behave as ideal gases, and follow PV=nRT. Pressure will increase or decrease to the same extent as the temperature increases or decreases regardless of which gas is in the tire. (Even at 300 psi, which is about 20 atm, there is little deviation from ideality.) Therefore the comments about N2 not changing in pressure as the temperature changes are without merit.

Well what you have said is true. But the advantage with nitrogen is that there is less moisture content in it when compared to the normal compressed air available at all our petrol bunks. And oxygen and nitrogen dont expand too much by themselves because of heat. The water vapour or moisture is what causes the pressure to change due to heat. I have access is 99% dry compressed air and I have found that this air behaves much better than nitrogen that we use. But one thing I have noticed from my experience is that the ride quality is better with nitrogen than with dried compressed air.

And what you have said about 90% purity of nitrogen is not true as even the most commercial nitogen available is 95% pure.

[sn48001]

If moisture content is the culprit, a moisture separator attached to the compressor would do the same job. The cost of installing a separator is fraction of the cost of nitrogen generator.

[sn48001]

The rate of diffusion of a gas through a porous membrane depends on the molar mass and to some degree on the molecular diameter. N2 and O2 are almost the same size and N2 is lighter than O2, so if either gas were to diffuse out of the tyre, nitrogen would do it more quickly. Luckily, tyres are designed not to be porous membranes.

[vikram_d]

Originally Posted by sn48001

If moisture content is the culprit, a moisture separator attached to the compressor would do the same job. The cost of installing a separator is fraction of the cost of nitrogen generator.

I totally agreee with you on this. But the problem is that nobody uses good quality moisture separators. The use 50micron separators which are not of any use for moisture purposes. For moisture they need to use at least 5 micron or even a 1 micron separator. But the best thing I have found that works is an air drier which I have in my factory for feeding compressed and 99% dry air to my machines.

Also the point of N2 being lighter than O2 is correct. It being lighter is the reason that the ride quality is much better than that of O2. And you have very rightly pointed out that the tyres are not porous. This sadly is a very popular misconception among people who think that tyres are porous. If they were then we would find tons of water in our tyres.

[sn48001]

Nitrogen is used in racing cars for three main reasons.

1) Even a small variations in tyre pressure due to moisture would be crucial to wining the race.

2) These tyres are heated up tremendously during the race that tyres may tend to flame out. So nitrogen would retard any such flame outs.

3) Using Highly compressed nitrogen cylinders in the pit for operating various pnuematic tools is easier than having a compressor running.

[n_aditya]

I've filled in nitrogen in my new Michelin XM1 tires.

I feel nitrogen doesnt heat the tires as much as regular air does...

I also heard that the pressure remains constant for as much as 6 months, as nitrogen is less volatile than free air... but i may beg to differ....

here's why....

i got these mich's in november... all 4 tires filled with nitrogen and the spare JK tubetype also filled with nitrogen...

Yesterday i went for a top-up of nitrogen as i felt one of the tires looked underinflated (front Left tire). And it was... 5 psi less... FR tire - 2-3 psi less.... Spare tire had no change in psi whatsoever....

Surprising.... the other tubeless tires also were down by a psi or two... i must admit that i hadn't used the car for 2 weeks.... but then.. we dont use the spare regularly so why the leakage only from the tubeless?

now for experts... is it recommended to check every month like we normally do? or we just let is be cos it's got nitrogen?

P.S. also if i have a puncture... how many days does it take for the tubeless to go completely or almost flat...???

[sandeep108]

Originally Posted by n_aditya

P.S. also if i have a puncture... how many days does it take for the tubeless to go completely or almost flat...???

A long time. I remember when I first moved to tubeless and after a year or so, I noticed that pressure in 2 of the tyres was always 5-8 psi less. Instead of 28-29, it was at 21-22, but would never go below this or got a flat. I checked weekly and for more than a month the same cycle repeated. Finally I called my tyre fellow and when he checked them there were three punctures in total for two tyres.

It could also be a valve issue. Using good quality valves is very important for tubeless.

[vikram_d]

Originally Posted by n_aditya

I've filled in nitrogen in my new Michelin XM1 tires.

I feel nitrogen doesnt heat the tires as much as regular air does...

I also heard that the pressure remains constant for as much as 6 months, as nitrogen is less volatile than free air... but i may beg to differ....

here's why....

i got these mich's in november... all 4 tires filled with nitrogen and the spare JK tubetype also filled with nitrogen...

Yesterday i went for a top-up of nitrogen as i felt one of the tires looked underinflated (front Left tire). And it was... 5 psi less... FR tire - 2-3 psi less.... Spare tire had no change in psi whatsoever....

Surprising.... the other tubeless tires also were down by a psi or two... i must admit that i hadn't used the car for 2 weeks.... but then.. we dont use the spare regularly so why the leakage only from the tubeless?

now for experts... is it recommended to check every month like we normally do? or we just let is be cos it's got nitrogen?

P.S. also if i have a puncture... how many days does it take for the tubeless to go completely or almost flat...???

If the tyre is deflating so much then there must be some other problem. It could be a problem with the valve neck or the tyre fitting itself. I filled in nitrogen in my car all 5 tyres in July and till date there has been no reduction in pressure. I would recommend that you check your pressure atleast every month to begin with and if the deflating continues then you will need to get your tyres looked at. Also check pressure on a regular basis while using your vehicle everyday for one month. I think this deflation has happened because of the vehicle not being used. Also what kind or rims are you using? It could also be a problem with the tyre and rim contact area. Check all these points that I have mentioned and I'm sure you will find the culprit.

[n_aditya]

Thanks Vikram.... Will monitor the pressure for sometime... BTW the wheels are all alloys which were OE fitment from Maruti (Limited edition esteem).

I think it is either an issue with valves or a puncture... will check and post findings.

Thanx guys.