# Nitrogen in tyres.



## sooty10 (Feb 22, 2009)

Anyone heard of this one. Reading a thread on another forum (sorry) one guy claims a 10% increase in mpg by having high pressure valves fitted and his tyres inflated with pure nitrogen. He said he had this done at ATS.
Thought it may have been the 1st of April but no, 3rd July.

Sooty


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## rotorywing (Jul 19, 2010)

Never seen a garage forecourt with Nitrogen, if you want to maintain 100% nitrogen in your tyres then you will be restricted to ATS garages etc for your weekly maintenance !!. Wouldn't like to comment on the increase in MPG........10% seems a bit extreme.

Aircraft tyres that were initially pressurised with shop air, that contained a percentage of oxygen, would explode when the tyre / brakes became overheated on takeoff, causing major damage to the airframe and cabin area. Hence the reason aviation changed to Nitrogen.


Martin


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## duxdeluxe (Sep 2, 2007)

Nitrogen filled road tyres? What a load of cobblers (in my humble opinion) Normal air which is in any case about 78% nitrogen is good enough for us mere mortals. All an excuse to charge more by the tyre fitting companies and I'm quite happy to take the risk of my tyres overheating and exploding because they also have 21% oxygen plus a bit of carbon dioxide in.........

10% mpg increase? Cloud cuckoo land. If it was true, everyone would have been doing it a long time ago.

(returns to normal from Victor Meldrew mode)


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## 747 (Oct 2, 2009)

I read that story and replied giving my doubts about it.

It is claimed that Nitrogen does not bleed through the rubber and the pressure should never drop. So, less maintenance.

One possible advantage is that if you use Nitrogen, you could get a Nitrogen bottle and then with a suitable adaptor, top up your tyre pressure without using a garage forecourt. But if they never leak, why bother?


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## statenisland (Aug 17, 2007)

*Nitrogen in tyres*

Good afternoon,

In last week's Sunday Times Ingear, Clarkson road tests the Nissan GT-R and reports that it has nitrogen filled tyres. Reason given is that 'normal air is too unpredictable. It expands and contracts appreciably according to tyre temperature. Nitrogen does not'.


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## spatz1 (May 19, 2011)

Had it in my tyres back in 2008 at £1.75 a tyre and its tosh it gives you better fuel consumption other than keeping tyres at a more constant pressure during air temperature fluctuations ...Today we ve had 13 degrees to 25 which might make a psi or 2 differance to tyre pressure.

It s aimed at sports cars where you can feel a psi or 2 out on pressures , not RV s that dont even specify a tyre pressure if you take mine for example !!!


edit... you beat me to it !


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## BillCreer (Jan 23, 2010)

*Re: Nitrogen in tyres*



statenisland said:


> Good afternoon,
> 
> In last week's Sunday Times Ingear, Clarkson road tests the Nissan GT-R and reports that it has nitrogen filled tyres. Reason given is that 'normal air is too unpredictable. It expands and contracts appreciably according to tyre temperature. Nitrogen does not'.


If Clarkson says that there is a good reason for it the then that's convinced me to avoid inflating with Nitrogen.

I might try Nitrous Oxide though.


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## dodger148 (May 9, 2005)

Aircraft have had Oxy Free Nitrogen (OFN) in their tyres for years. Keeps them cooler on landing. I dont know how it would affect the mpg in road vehicle though. You are not restricted to ATS you can always get a cylinder from BOC or Air Products, fit a regulator and hose with a tyre inflator on the end and bingo. Many moons ago I sprayed a car with OFN (I had access to a good supply) instead of compressed air


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## karlb (Feb 22, 2009)

if your interested in nitrogen tyres you might like this aswell

http://www.wired.com/gadgetlab/2007/11/10-awesome-gadg/


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## DTPCHEMICALS (Jul 24, 2006)

:lol: :lol: :lol: :lol: :lol: :lol: :lol: 
Debated many times 

Good old fashiond air for me thanks.

My track bike runs well enough on it and so does the mh
Dave p


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## Penquin (Oct 15, 2007)

Air is approx 78% Nitrogen, 21% oxygen plus a variety of minor gases. Gases expand and contract in the same way as temperature changes as evidenced by Boyles Law I believe (Pressure x volume = a constant) and Daltons Law of Partial Pressures - which basically means each gas exerts the % of the total pressure equivalent to it's own % of the mixture. :? 

The debate about oxygen in aircraft tyres is logical - they are subject to high temperature when landing due to the pressure on them (yet another of the Gas Laws) and oxygen does support combustion.  

So having only nitrogen in them would remove the risk of spontaneous combustion due to the sudden increase in temperature on landing. Rubber does burn - as we have all seen (and smelled) so reducing that risk increases aircraft safety.  

If you increase the pressure inside the tyre you reduce the area of the tyre in contact with the road as the tyre surface curves more - that reduces the friction and could increase the mpg slightly but 10% would be a major surprise....... :roll: 

Of course if you reduce the amount of tyre in contact with the road you reduce the control over direction that you have.....  

And there are limits for tyres anyway - if you exceed that what might happen to your insurance........... ?  :lol: 

I will stick with air thanks.....  

Dave


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## DavidDredge (Oct 17, 2010)

Its a money making ploy for garages. The fuel consumption benefit is true only if you never check your pressures and thus constantly run at low pressure (oxygen in air leaks out of tyres over time). Anyone who does not regularly check their pressures is a fool so could well be taken in by this!


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## b2tus (Sep 7, 2009)

Had two tyres fitted recently to our car at ATS. Good price for the tyres and then came the nitrogen question......special offer Sir etc etc etc. Told them I was not interested.
Tyres fitted and bill was presented with usual umpteen lines of pricing, disposal of old tyres, etc etc including 4 tyres filled with nitrogen. Told them I said had said no but they thought I had said yes. They eventually agreed with me and said what do we do now?????...the nitrogen is now in the tyres. Shame says I..... let it all out and then fill them back up with normal air.

They left the nitrogen in all four tyres and deducted the cost from the bill.
I have not felt or noticed any difference whatsoever including mpg. 

What a con.:roll:


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## duxdeluxe (Sep 2, 2007)

Oddly enough, when I changed a couple of tyres on the Merc two weeks ago, Kwik Flit actually used nitrogen to inflate the tyres - or at least that is what it said on the "bill" - it is a leased car so I don't know (or indeed care) if it was paid for but I did watch them using what looked like a normal air line rather than one that would have been clearly marked in some way. I was a bit surprised that a major lease company would accept this sort of charge anyway - normally they are tighter than a tight thing when it comes to what they pay for. If you pay for nitrogen inflation, are you actually getting it? Anyone got a portable gas chromatograph? Hmmm yes we have actually. Might have a word with the lab and check it out...... Also, might not bother!


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## Rosbotham (May 4, 2008)

Change your tyres at Costco. Nitrogen inflation's standard so the "are they ripping you off" question doesn't come into it.


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## Mrplodd (Mar 4, 2008)

A fool and his money are soon parted ?????

Just how many years have we all been happy with "standard" air in our tyres. 

I bet it wont be long before some bright spark with an eye to making a few quid comes up with a "reason" to use another inert (and of course expensive  ) gas such as Xenon, or Argon to inflate tyres.

Just my opinion but what a load of B*****s :lol: :lol: :lol:


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## mjpksp (May 8, 2010)

I always thought the use of pure nitrogen in sports car tyres was to eliminate the water vapour that is naturally found in air?

Why do oxygen molecules diffuse through rubber tyres quicker than nitrogen molecules? If this is the case then surely by allowing tyres to naturally 'deflate' with time and then topping them up with air you can purify the nitrogen. Eventually you will end up with almost pure nitrogen inside the tyre won't you??? If you do the process in a closed environment umpteen times then surely you could purify the oxygen outside?? Have I just discovered something new and should I patent the process?


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## macone48 (Mar 14, 2006)

Yes ......A fool and his money etc....!!

However, comma, Nitrogen is what it says a pure gas when dispensed, whereas "air" is a mixture of all sorts including water vapour at all sorts of percentages.

This latter aspect is what F1 and other racing Teams/Tyre users seek to remove as with usage/temperature it has the greatest influence on tyre pressures, therefore, grip, performance and Results!!!

Replace "air" with an inert gas, and there is a very stable relationship versus temp/pressure & Nitrogen is the most plentiful and probably cheapest, relatively speaking, for an F1 Team.

If F1 does it then it must have a spin-off as Kwick-Fit & others have found............a fool and his money.....unless he's racing at Silverston next weekend!!!

HTH

Trev


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## mjpksp (May 8, 2010)

macone48 said:


> If F1 does it then it must have a spin-off as Kwick-Fit & others have found............a fool and his money.....unless he's racing at Silverston next weekend!!!
> 
> HTH
> 
> Trev


I've yet to find a Kwick Fit that can change a tyre in 30 min let alone 5 seconds. Can you imaging if pit crews started to try and sell brake tests, air con recharges, exhausts, etc whilst the F1 car was in the pit? That would be a whole new dimension to races.

Murray Walker (or other commentator): "and jensen button has resisted the temptation to have his rear exhaust replaced when he went in for a new dust cap!"

I pride myself in being able to go off at a tangent!


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## CliveMott (Mar 10, 2008)

Air is already 80% Nitrogen. I don,t expect you will be able to see any difference in economy if you used 100% nitrogen. You may however see an small fall in fuel consumption if you increase tyre pressures, whatever you inflate them with.

C.


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## mjpksp (May 8, 2010)

Surely filling them with helium is the answer so that you 'float' and reduce friction?


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## 5bells (Feb 4, 2009)

In order to ensure that 100% Nitrogen is injected into the tyes you would have to evacuate ALL of the residual air in the tyre.
This is virtually impossible without damaging the integrity of a semi rigid walled tyre.

If you want to eliminate most of the moisture from the air going into your tyre then use a diving air compressor which filters and dries the air via the filter/dryer unit on the compressor(what else)
Just kidding of course it would be quite dangerous if you did not know what you were doing but if you are going to be daft enough to pay for the dubious benefit of nitrogen in a van tyre which has to be replaced every five or six years it does not make sense to me.

As for the "increase" in MPG if my tyre pressure increases by a couple of psi when warm this will improve my mpg :lol: 

Sounds like a lot of hot air (or nitrogen ) to me for the type of vehicles we drive but, I have an open mind.

Ray


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