Filling tyres with nitrogen - Is it worth it?

old-git

old-git

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Before going down this route, read this:

The air you breathe is already made up of 78% nitrogen. The composition is completed by 21% oxygen and tiny percentages of argon, carbon dioxide, neon, methane, helium, krypton, hydrogen and xenon. The kit that is used to generate nitrogen for road tyres typically only gets to about 95% purity.

To get close to that in your tyres, you'd need to inflate and deflate them several times to purge any remaining oxygen and even then you're only likely to get about 90% pure nitrogen. So under ideal conditions, you're increasing the nitrogen content of the gas in the tyre from 78% to 90%.

Given that nitrogen inflation from the average tyre workshop is a one-shot deal (no purging involved) you're more likely to be driving around with 80% pure nitrogen than 90%. That's a 2% difference from bog standard air. On top of that, nitrogen inflation doesn't make your tyres any less prone to damage from road debris and punctures and such. It doesn't make them any stronger, and if you need to top them up and use a regular garage air-line to do it, you've diluted whatever purity of nitrogen was in the tyres right there. For $30 a tyre for nitrogen inflation, do you think that's worth it? For all the alleged benefits of a nitrogen fill, you'd be far better off finding a tyre change place that has a vapour-elimination system in their air compressor. If they can pump up your tyres with dry air, you'll get about the same benefits as you would with a nitrogen inflation but for free.
 
I had nitrogen filled tyres in my old focus.
I couldn't tell the difference. I'm in agreement with what you say OG. The benefits if any are very minute IMO.
 
My tyres have been nitrogen filled for years. The difference I notice is when taking bends and corners and while travelling at high speeds. The tyre shape holds much better with the nitrogen than with air, so I find I can really push the speed around corners without the tyre trying to leave the rim. Also, the tyre valve is removed and the tyre is allowed to go completely flat to expel as much air as possible. The tyre is then re-inflated with the nitrogen.

Also the nitrogen is thicker than air so is less likely to leak around the rim losing pressure as air does, a fact that I have verified by checking my tyre pressures fortnightly with no loss and yes using the same portable tyre pressure gauge.

Not sure where that ridiculous price tag came from for the cost of the nitrogen, but in Kwik-Fit where I get my tyres done, it costs me just £1.50 per tyre and that has come down to £1.00 as the guys like my car. Even after I get my wheels kerb/potholes damage repaired, I get straight down to Kwik-Fit and have the air removed and the nitrogen put back in.

I will NEVER go back to air!
 
^^ Very possible buddy, but for my own observations, I can be much bolder on the track with the nitrogen in around the bends than if the tyres were filled with just air. Some people would begrudge spending this kind of money on what I deem to be an enhancement but each to their own.
 
T9 man said:
My tyres have been nitrogen filled for years. The difference I notice is when taking bends and corners and while travelling at high speeds. The tyre shape holds much better with the nitrogen than with air, so I find I can really push the speed around corners without the tyre trying to leave the rim. Also, the tyre valve is removed and the tyre is allowed to go completely flat to expel as much air as possible. The tyre is then re-inflated with the nitrogen.

Also the nitrogen is thicker than air so is less likely to leak around the rim losing pressure as air does, a fact that I have verified by checking my tyre pressures fortnightly with no loss and yes using the same portable tyre pressure gauge.

Not sure where that ridiculous price tag came from for the cost of the nitrogen, but in Kwik-Fit where I get my tyres done, it costs me just £1.50 per tyre and that has come down to £1.00 as the guys like my car. Even after I get my wheels kerb/potholes damage repaired, I get straight down to Kwik-Fit and have the air removed and the nitrogen put back in.

I will NEVER go back to air!
Click to expand...

Hi Os

Never taken issue with you before, but I guess there is a first time for everything :)

Just letting the tyre go flat still leaves a lot of air in the tyre. If running at 30psi inflated a flat tyre will be at 14.7psi. As the rubber doesn't expand very much (too much steel in it) a flat tyre will contain approx 50% of its inflated volume of air.

Tyre shop nitrogen is approx 95% pure (at best).

As air is already 78% nitrogen the increase in the nitrogen percentage will be minimal unless the tyre is purged with nitrogen a few times. If the remaining air isn't purged you will end up with 86.5% nitrogen, an increase of 8.5%

Theoretically, if the tyre shop managed to purge 100% of the air from the tyre by repeatedly filling and emptying (highly unlikely), the best you can hope to acheive is an increase in nitrogen of around 17%.

I fail to see how nitrogen can make such a difference in handling when the tyre pressures (which have the greatest effect) will be the same. More info on how nitrogen holds the tyre in a better shape (I always assumed it was the pressure that did this) would be very useful as I can't find any.

The one thing I can agree on :) is that nitrogen leaks out at about a third as fast as air. But it still leaks out so regular checks are still required.
 
Surely it's the other parts that make up air which leak away more rapidly. So filling a tyre to 50psi with air and then leaving it alone for a couple of years the majority of what seeps away will not be nitrogen, leaving you with a 40PSI nitrogen inflated tyre :-D

I use normal air in mine but I check them weekly and adjust even the smallest differences. I also run mine at the full load/full speed settings as the firmer sidewall gives better steering feel, better grip and better wear characteristics. Slightly harsher ride is the payback.
 
No problem and no issues with you at all Steve :)

At the end of the day anyone and everyone can find the information to either prove or disprove their own theories or hypothesis if they dig far and deep enough. As stated before, my explanations of nitrogen's virtues are based on my own personal findings, so I am really not interested any other technical data that may get thrown forward, yet I respect them all the same ;)
 
After reading og's side and t9's the benefits may well be a placebo affect!? Which in scientific research they have been proven to work:lol:
 
Just realised that I made an error in a previous posting.

Air remaining in a deflated tyre is at atmospheric pressure of 14.7psi - Correct

However, if inflating to 30 psi, that is 30psi ABOVE atmospheric, so the percentage of air in an uninflated tyre is 33% not 50%, thus altering the subsequent results by a couple of percent but not the conclusions,

Apologies for error.
 
Just had a brief chat with Kwik Fit re how they fill tyres with nitrogen.

All they do is let the pressure out of the tyre then refill with nitrogen, so my theory above remains valid - A tyre at 30psi will contain 1/3 air and 2/3 nitrogen. At maximum you will get 85-90% nitrogen from Quik Fit, but probably less. IMO not really worth the effort and inconvenience. The tyres will still lose pressure at virtually the same rate as filled with 100% free air.

However, if you still want to use nitrogen, but effectively, then follow Carroll Smith's method:

"If you are going to use nitrogen in your tyres, evacuate the tyres first with a vacuum cleaner. Leave the vacuum hooked up for at least five minutes."
 
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Indeed, Formula 1 use nitrogen and have been doing so since at least 2007, they do however use an uninflate system first before the special nitrogen rich air mixture is inserted.
 
I wonder what the "nitrogen rich air mixture" contains as it seems to be a contradiction in terms?
 
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Air is nitrogen rich anyway! I'm slightly baffled too.

Not sure I'm ever going to bother with nitrogen as I'm a twice a week tyre pressure checker so not much chance for pressures to deviate very far.
 
Will have to find out the in's and out's on this one. Formula 1 do not do anything to their cars unless there is a serious benefit to be had. Something I read not too long ago (this afternoon actually) was that air has moisture in it and therefore with heat applied it has a very bad effect on the pressure that the tyre maintains, thus nitrogen is used which does not have this effect to minimise the air (what little there is off it) inside the tyre.
Also another fact I found out earlier, in March 2009 Nissan GT-R had tyres developed specifically for nitrogen which was filled at the factory.
 
F1 strives for every gram of performance. The main problem is that the moisture present in air causes pressure fluctuations due to the high temperatures that the tyres run at.

Dried air would be just as good but, as they already use bottled nitrogen for air tools (for the same reason of moisture) it is a no brainer.

Just found this and I think it sums it up nicely:

[FONT=Verdana, Arial, Helvetica, sans-serif]Another interesting point is that most of the F1 teams use dry nitrogen gas to inflate their tyres instead of air. This is done for two reasons.

Firstly the moisture content of air is variable depending on the local weather conditions and this differs considerably between some of the exotic locations on the GP calendar. By using dry nitrogen gas the tyres will behave in a predictable way wherever they are being used.

The second reason is that air is a mixture of nitrogen (78%) and oxygen (21%). Oxygen gas is far more reactive than nitrogen and at the high operating temperatures of F1 tyres (> 100°C) the oxygen reacts with the tyre, reducing the total pressure inside. Using pure nitrogen removes this problem and tyre pressures remain far more consistent.

These are the reasons why F1 uses nitrogen and none of them is relevant to street or even track day cars. Smoke and mirrors, expecially when considering the way garages install it.
[/FONT]
 
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It does no harm so I won't be insisting that you remove it :)

I have considered it for my race tyres. However, any gain would be difficult to quantify as it would be marginal at best and as a lot of pressure adjusting goes on at the track I would need a bottle of the stuff.
 
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I am wondering if the density of the filling medium has any effect upon it's ability to support the tyre. Am looking for ways to rationalise the reasons why some people feel their cars handle better with nitrogen inflation.
 
The density of nitrogen is not a lot different to oxygen so there would be no noticable difference. I'm thinking it is simply a combination of their tyres being inflated to the correct pressure and the 'aftermarket air filter' placebo effect.
 
still not sure which is best!!, but have got nitrgen in my tyres mainly cos my local ats puts mine in for free !!,i think it,s about £1,50 a tyre normally,not sure!
 
gummy said:
still not sure which is best!!, but have got nitrgen in my tyres mainly cos my local ats puts mine in for free !!,i think it,s about £1,50 a tyre normally,not sure!
Click to expand...

Do they totally remove all the air with a vacuum, fill/empty/refill a few times or just let them down? If the latter, then you will still have approx 33% air in your tyres :)
 
old-git said:
Before going down this route, read this:

The air you breathe is already made up of 78% nitrogen. The composition is completed by 21% oxygen and tiny percentages of argon, carbon dioxide, neon, methane, helium, krypton, hydrogen and xenon. The kit that is used to generate nitrogen for road tyres typically only gets to about 95% purity.

To get close to that in your tyres, you'd need to inflate and deflate them several times to purge any remaining oxygen and even then you're only likely to get about 90% pure nitrogen. So under ideal conditions, you're increasing the nitrogen content of the gas in the tyre from 78% to 90%.

Given that nitrogen inflation from the average tyre workshop is a one-shot deal (no purging involved) you're more likely to be driving around with 80% pure nitrogen than 90%. That's a 2% difference from bog standard air. On top of that, nitrogen inflation doesn't make your tyres any less prone to damage from road debris and punctures and such. It doesn't make them any stronger, and if you need to top them up and use a regular garage air-line to do it, you've diluted whatever purity of nitrogen was in the tyres right there. For $30 a tyre for nitrogen inflation, do you think that's worth it? For all the alleged benefits of a nitrogen fill, you'd be far better off finding a tyre change place that has a vapour-elimination system in their air compressor. If they can pump up your tyres with dry air, you'll get about the same benefits as you would with a nitrogen inflation but for free.
Click to expand...
It's not worth it.
 
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