N27 - Nitrogen vs Compressed Air in Tyres

[tig18u]

Hey fellow Tig owners,

Reading up on Nitrogen in tyres (the benefits all seem logical) it appears not many car owners bother with, those that do, dont go back to compressed air.
The benefit factor comes from volume, deeper or wider the tyre, better its retention of pressure over time (air vs nitrogen).

since I am novice to N in Tyres, I am asking the wider forum if anybody has had long term experience (years + ) to share some first hand feedback.

Marketing write ups aside, Compared to compressed air, is it really the case of less then 5% of pressure loss over a 12mths period (nitrogen inflated), normal driving conditions etc.

Thanks.,
Z

[team_v]

Air consists of about 78% nitrogen anyway so there is no need for daily driving or even moderate track use.
The only requirement would be if you were to do professional racing.
Otherwise it's just money in someone elses pocket.

I filled my tyres up (38 fronts and 36 rears) about 2 months ago and they only dropped 1psi since then.

[Captain Bungers]

I have nitrogen in the Subaru Forester's tyres - I got it done when we got new tyres about 18 months ago. I haven's had to get them refilled yet as they have only dropped a few psi since...

Having said that I should really go and get them filled again...

[kaanage]

There has been loads of debate on this with adherents on both sides
Here's a fairly recent example http://www.vwwatercooled.org.au/foru...res-60065.html

[shakespeare]

Air consists of about 78% nitrogen anyway so there is no need for daily driving or even moderate track use.
The only requirement would be if you were to do professional racing.
Otherwise it's just money in someone elses pocket.

I filled my tyres up (38 fronts and 36 rears) about 2 months ago and they only dropped 1psi since then.

I'm with Team V, known a few people who've tried it, but when it comes time to inflating your tyres you need to go back to your tyre dealer so they can inflate them with nitrogen again! They got tired of the novelty and when back to air, when asked if they felt a difference, answer was "none whatsoever" Also mine only lose 1 psi or so over a few months (and I've got 35 series rubber on 19" rims and there are some "not kind to low profile rubber" roads here in WA)

[kryten2001]

Got it done for free when I had my R spec tyres put on. I certainly wouldn't pay for it though, it's just a way for tyre fitters to make a few extra bucks in a very competitive market imho....

[fred27]

For racing, I found less pressure variation from cold to hot with nitrogen, and it leaks out less than compressed air.
Same thing with my street tyres.
Hope all of the above helps with your decision.

[wai]

There is no real benefit for normal use.

Nitrogen is the norm for aircraft tyres because most of the time they are not used, and only become critical when taking off or landing. While stowed at elevation and low temperatures, even the slightest amount of water vapour will condense out and over time can cause corrosion and therefore a leak rendering them useless when it comes time to land. This is not the case with normal use in vehicles.

It is a marketing exercise in line with low fat milk.

To use nitrogen in car tyres correctly after the tyre is slipped on to the rim, it would have to go into a drying chamber to make sure that all the water used to get it on to the rim is removed. This chamber would have to be filled with pure nitrogen. The bead would have to be seated in this chamber and then nitrogen would have to be used to get it to the correct pressure. Then when checked, you can only use nitrogen. Any compressed air added to the tyre would make the whole exercise useless.

This does not happen. Even in racing situations, the tyres are fitted and then nitrogen is added to the air in the tyre to bring it up to correct pressure.

As for tests that people carry out, the only way a comparison can be made is for either two vehicles to be used (one with nitrogen and one with air) where they are driven identically, or for two wheels to have nitrogen and two wheels with air. Even here you would have to swap things over to eliminate any bias.

It comes down to this. If you want to use nitrogen, then pay extra and go with it. If not, then stick with air and save a few dollars. There no real difference between them except for cost. If you feel it makes a difference, just make sure it is an actual difference and nothing else.

[tig18u]

I understand why a tyre shops would recommend topup of N27 at their premisses (some do charge a small fee, most would do it as a complimentary service for a returning customer) however, considering the fact that the PSI loss is negligible (2-3 PSi over a longish period) one could just carry out home checks and top-up with compressed air instead.
Choosing a servo where the equip looks newish hopefully indicates a newish compressor (or at least one that has a less chance of water carrying thru)
A good idea is to always bleed the line first to check for moisture prior inflating any tyre at the servo anyhow.

Thanks for the comments members.
The benefit of N27 in tyres seems to be in the eyes of the beholder (cliche`). No real benefit unless the purpose of use pushes the limits where compressed air would normally not cope. ie: racing, constant driving (heavy vehicles) etc.

perhaps the thread would help others draw their own conclusions, heck that`s why we have these forums.

[greymad]

There is no real benefit for normal use.

Nitrogen is the norm for aircraft tyres because most of the time they are not used, and only become critical when taking off or landing. While stowed at elevation and low temperatures, even the slightest amount of water vapour will condense out and over time can cause corrosion and therefore a leak rendering them useless when it comes time to land. This is not the case with normal use in vehicles.

It is a marketing exercise in line with low fat milk.

To use nitrogen in car tyres correctly after the tyre is slipped on to the rim, it would have to go into a drying chamber to make sure that all the water used to get it on to the rim is removed. This chamber would have to be filled with pure nitrogen. The bead would have to be seated in this chamber and then nitrogen would have to be used to get it to the correct pressure. Then when checked, you can only use nitrogen. Any compressed air added to the tyre would make the whole exercise useless.

This does not happen. Even in racing situations, the tyres are fitted and then nitrogen is added to the air in the tyre to bring it up to correct pressure.

As for tests that people carry out, the only way a comparison can be made is for either two vehicles to be used (one with nitrogen and one with air) where they are driven identically, or for two wheels to have nitrogen and two wheels with air. Even here you would have to swap things over to eliminate any bias.

It comes down to this. If you want to use nitrogen, then pay extra and go with it. If not, then stick with air and save a few dollars. There no real difference between them except for cost. If you feel it makes a difference, just make sure it is an actual difference and nothing else.

I'd always understood that the reason in motor racing for using N2 rather than air was to minimise pressure rise with increased temperature - as the air, even though being 78% N2, had a greater coefficient of themal expansion. In street use I see it as a load of w**k - something to brag about (like 35 profile tyres in the street, but it's only my opinion .. go ahead & spend the $$ if you want).
What I had NOT thought about was the use of N2 in aircraft where it's bleedingly obvious that if the tyres are subjected to hours of seriously sub zero temperatures, you don't want the pressures to be off (ie below) spec when you touch down. Thanks, Wai...

[Diesel_vert]

The other reason why it's used in aircraft is for safety reasons as, for the most part, nitrogen is inert.

I'd always understood that the reason in motor racing for using N2 rather than air was to minimise pressure rise with increased temperature - as the air, even though being 78% N2, had a greater coefficient of themal expansion.

The ideal gas law shows that, for the same volume (e.g. inside a tyre) gases expand when temperature increases (i.e. tyre pressure increases) and contract when temperature decreases (i.e. tyre pressure decreases).

Fundamentally, air, oxygen and nitrogen don't behave much differently from each other in this respect.

However, when great accuracy is required, changes in pressure are more predictable to racing teams if you use a dry gas or eliminate water vapour.

[greymad]

The other reason why it's used in aircraft is for safety reasons as, for the most part, nitrogen is inert.



The ideal gas law shows that, for the same volume (e.g. inside a tyre) gases expand when temperature increases (i.e. tyre pressure increases) and contract when temperature decreases (i.e. tyre pressure decreases).

Fundamentally, air, oxygen and nitrogen don't behave much differently from each other in this respect.

However, when great accuracy is required, changes in pressure are more predictable to racing teams if you use a dry gas or eliminate water vapour.

So using it in road car tyres is definitely a w**k and waste of money...

Edit: just chased this one up: well worth a read.
http://www.btmauk.com/data/files/Nit...-car-tyres.pdf

[LunchboxVRS]

A little water in the air should only be a worry if you have steel wheels and the paint has come away from the inside (providing there painted).

[greymad]

A little water in the air should only be a worry if you have steel wheels and the paint has come away from the inside (providing there painted).

It doesn't worry me, but aircraft folk tend to be somewhat anal retentive about anything to do with "corrosion".

[LunchboxVRS]

It doesn't worry me, but aircraft folk tend to be somewhat anal retentive about anything to do with "corrosion".

Aircraft folk get anal about anything...But you will know if a pilots around cause he will tell you.