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Hi. I have just had a couple of new tyres fitted and noticed I have been charged £2.50 for a "nitroinflate". Presumably they have inflated the tyres with nitrogen rather than air. I am not quibbling, just interest as to why ? I would imagine nitrogen would diffuse through rubber a little quicker than air. If it is to keep oxygen out of the tyre (to reduce oxidation ?), there is plenty of oxygen on the outside anyway. Besides, when I pump them up I will just put air in. Any BRers care to enlighten me ?
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See
www.honestjohn.co.uk/forum/post/index.htm?t=22236
for some info
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Ever since they were invented, pneumatic tyres have been inflated with 80% Nitrogen. It's called AIR!
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Nitoinflate is an excuse for the fitter to charge you for blowing the tyres up. Can you prove it isn't ordinary air in the tyre?
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The nitro inflation stations remove the components of compressed air that are considered undesirable in tyre inflation,ie water, oil vapour, and oxygen. Oxygen molecules are approx 10times smaller than nitrogen ones and therefore the tyre pressure remains correct for a lot longer. This means that the road holding and handling will be much improved for longer. The tyre will wear much better and last longer. Fuel consumption will reduce, and because of the lack of oxygen and water vapour in the tyre /wheel assembly there will be little if any corrosion. Who uses Nitrogen as a standard ??? All Formula 1 cars for the last 20 years and it is mandatory for all commercial airlines... To answer the point that you dont know wether you are getting nitrogen, well all outlets are checked by Trading Standards and have regular certificated tests to prove the nitrogen purity. Wether £2.50 is value only you can judge, however there are some independents out there who inflate with nitrogen FOC on all new tyres fitted, despite the cost of the equipment being over £1700.00
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Got four new Eagle GSD3 F1 225/45x17 tyres fitted to my V70 when on holiday in the Czech Republic. Swanky chromed valve spems and caps and bottled nitrogen inflation was included in the competitive £400 total cost.
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Same price as over here
Yes indeed, but still as I wrote, competitive.
For the record though, they showed care and attention never once personally experienced at a UK fast fit outlet. The guys had real pride in their work and in their spotlessly clean and organised working environment. I was also asked to come back later in the day to have the bolt torque checked; I just wish they were rather more local to Aylesbury!
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The nitro inflation stations remove the components of compressed air that are considered undesirable in tyre inflation,ie water, oil vapour, and oxygen. Oxygen molecules are approx 10times smaller than nitrogen ones and therefore the tyre pressure remains correct for a lot longer. This means that the road holding and handling will be much improved for longer. The tyre will wear much better and last longer. Fuel consumption will reduce, and because of the lack of oxygen and water vapour in the tyre /wheel assembly there will be little if any corrosion. Who uses Nitrogen as a standard ??? All Formula 1 cars for the last 20 years and it is mandatory for all commercial airlines... To answer the point that you dont know wether you are getting nitrogen, well all outlets are checked by Trading Standards and have regular certificated tests to prove the nitrogen purity. Wether £2.50 is value only you can judge, however there are some independents out there who inflate with nitrogen FOC on all new tyres fitted, despite the cost of the equipment being over £1700.00
I bow to your superior knowledge on tyres but you should ask for a refund on that chemistry degree you purchased :o) Did it come free with the nitrogen generator???
Things move on in chemistry over the years, but I was not aware of just how far oxygen and nitrogen molecules had diverged in terms of size. That'll be inflation, right?
As for internal oxidation of tyres - is that a big factor for failure these days? I suppose it must be - I bow to your knowledge
I imagine that F1 teams use (bottled, certified) pure DRY nitrogen as it is easier than compressing and drying air at various points around the world. 1/2 psi is a big deal in F1 and using a standard dry gas makes sense.
Aircraft - let me see... Why would they want to avoid water vapour in their tyres at very high altitudes... no, you have got me on that one. Waste of time, but at least specifying nitrogen would remove the chance of water vapour so we don't need to worry anyway.
If I was asked to pay for this stuff in my tyres I would want a Certificate of Analysis. I'm pretty sure that the stuff coming out of the nitrogen generator at Weird-Fit ain't what F1 teams or aircraft are using in their tyres, just a guess now ;o)
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Aircraft use nitrogen to inflate the tyres as bursting tyres on heavy landings is one of the more commonplace (albeit still very rare!) accidents. So inert gas is used to reduce the risk of a wheel fire.
I don't know what generator the tyre shops are using, but there are nitrogen generators available that produce gas of equal or better purity than bottled nitrogen - we use one to supply inert gas to the instruments in our laboratory at work.
- Gromit
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Aircraft use nitrogen to inflate the tyres as bursting tyres on heavy landings is one of the more commonplace (albeit still very rare!) accidents. So inert gas is used to reduce the risk of a wheel fire. I don't know what generator the tyre shops are using, but there are nitrogen generators available that produce gas of equal or better purity than bottled nitrogen - we use one to supply inert gas to the instruments in our laboratory at work. - Gromit
I don't doubt that they are available. I'm just not sure that £1700 gets you one installed around the back of a tyre fitters.
Even if it does - I will risk my life with compressed air thanks, crazy and dangerous as that may be. Lock me up if you want ;o)
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I presume that the new tyre is full of air at one atmosphere when placed on the rim.
Then they pump in a couple,say, more atmospheres of nitrogen.
So only 2/3 of the contents is actually pure nitrogen.
Or maybe they evacuate the tyre contents first?
Bah Humbug.
--
I wasna fu but just had plenty.
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I presume that the new tyre is full of air at one atmosphere when placed on the rim. Then they pump in a couple,say, more atmospheres of nitrogen. So only 2/3 of the contents is actually pure nitrogen. Or maybe they evacuate the tyre contents first? Bah Humbug.
If the Nitroride system is used then this system does require an evacuation procedure, which is automatically built into the inflation process...
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Haardvark I bow to your patronisingly superior chemical knowledge, I should have said that the nitrogen generated by the UNIFLATE system permeates from the tyre 10 times slower than standard compressed air, which leads to the benefits I have previously mentioned. You are wrong with your F1 comments as the UNIFLATE system being used by every F1 team at every Grand Prix since 1992. Yes we do have a certifcate to show the content of the gas we pump which not only is checked externally but we also have our own piece of kit with which we do a daily check. Also we do not charge for this service when we fit new tyres to our customers vehicles, so I suppose we could rename ourelves as Weird-Fit. I suggest you check out the following WWW.UNIFLATE.COM where you will also be able to read the Which report about this "rip off" system. Most independents care about their customers, because if we do not fit we do not eat. You have obviously been to too many nationals, about whom I could not possibly comment...
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Haardvark I bow to your patronisingly superior chemical knowledge, I should have said that the nitrogen generated by the UNIFLATE system permeates from the tyre 10 times slower than standard compressed air, which leads to the benefits I have previously mentioned. You are wrong with your F1 comments as the UNIFLATE system being used by every F1 team at every Grand Prix since 1992. Yes we do have a certifcate to show the content of the gas we pump which not only is checked externally but we also have our own piece of kit with which we do a daily check. Also we do not charge for this service when we fit new tyres to our customers vehicles, so I suppose we could rename ourelves as Weird-Fit. I suggest you check out the following WWW.UNIFLATE.COM where you will also be able to read the Which report about this "rip off" system. Most independents care about their customers, because if we do not fit we do not eat. You have obviously been to too many nationals, about whom I could not possibly comment...
OK, it's the special nitrogen generated by the machine. Not the regular stuff contained in air at 80%. My mistake.
Wanna buya bridge??
HV
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F1 teams have their own compressors.Tyre pressures are set to within 0.1 psi.
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How long before we get the inert gas of our choice, I wonder? Personally, I favour Krypton...
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Whatever happened to the portable compressed air cylinders that used to be provided at petrol stations for inflating tyres? Much easier to use than an airline. You could inflate your tyres wherever the car happened to be ~ and no waiting for the airline to become free.
--
L\'escargot.
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I would imagine they all got stolen.
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Nitrogen has been used in tyres where there is a risk of explosion (e.g. aircraft, F1 cars), where high pressures are involved or there is a risk of an electrical dischage. The natural/vulcanised rubber that tyres are made of perishes when exposed to water and oxygen due to oxides and bacterial decay.
So, by removing both oxygen and moisture from the air, the process can be reduced, almost doubling the life of the tyre. However, I suspect that this last benefit seems a bit academic since the tread will probably have worn out long before that happens.
Andy
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Hi Robert,
The reason for Nitrogen inflation is that Nitrogen is denser than air and therefore will not dissipate through the innerliner of your tyre as quickly as air helping to retain the correct pressure for much longer. Nitrogen has been used in Formula 1 for around 15 years. Nitrogen also contains much less moisture than air therefore helping prevent rim corrosion from the inside of the tyre.
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HJ covered this in his newspaper column. I quote a response he received. I hope it's OK to quote from the Telegraph site.
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"Your recent assertion that oxygen molecules are 10 times smaller than those of nitrogen is mistaken, as pointed out by a letter writer last week. Both elements have naturally occurring molecules, N2 and O2, which are almost exactly the same size.
The rate at which a gas passes through a membrane (a tyre wall, in the instance you described) is governed by Fick's Law, from which it can be shown to depend on a number of factors. As a first approximation, one may assume these to be: the thickness of the membrane, the pressure difference across the membrane, and the permeability of the material of the membrane to a particular gas.
The last of these is itself dependent upon the emissivity of the surfaces, ie, the rate at which a gas is absorbed by or released from that surface, the solubility of the gas in the material of the membrane and the diffusivity of the gas (how quickly the gas moves through the material, in other words).
Bearing some of this in mind, normal air is roughly 79 per cent nitrogen and 21 per cent oxygen, so filling your tyres with nitrogen will only replace about one fifth of the gas in it. That will produce a situation in which the environment outside the tyre is comparatively rich in oxygen, which will then permeate into the tyre, driven by its natural partial pressure, thereby increasing the combined pressure within the tyre.
Without carrying out the proper calculations, one could reasonably predict that this increase might be noticeable, were regular checks carried out. However, while the oxygen is creeping in, some of the nitrogen might seep out and the effects, to some degree, balance. Drivers would be far better advised to check their tyre pressures regularly, whatever means of inflation they use, rather than waste money on expensive systems of doubtful merit. "
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Snake oil, I suspect.
V
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F1 teams originally went to nitrogen due to there own decision at they could obtain medical dry nitrogen bottles, which provided a better cold to hot tyre pressure ration as there was no or extremely little water in it to vapourise and artificially raise the type pressure. The added advantage of the inert gas and high speed blow outs attracted the attention of the governing body and the regulation was put in place. Now before somebody states that oxygen does not burn, we now that already, the problem is the cloud of dust created when the tyre goes bang, the red hot brakes and the sparks from the alloy rim can ignite the dust oxygen mixture and completely blow the tyre off the rim rather half off and leave the driver a lttile control of his destiny.. Nitrogen is a cheap safer solution to a potential problem. I came from an A/C invloved background and there, as someone has mentioned, water in the tyre can be a big problem, anything from vibation due to ice unbalancing the wheel to rapid over infaltion due to the rapid heating on landing so nitrogen has been used for more years than I care to remember. So that's my pennies worth. If the more knowledgeable guys want a good laugh visit some of the boy racer forums and search on nitrogen, apparently it improves your 0-60 times and road holding. Made I Laugh. Regards Peter
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in the tractors i used to drive on the farms, the tyres were filled with water and air to add ballast and improve grip. Tyres still lasted loads and loads of years and wore out rather than perished, which pleased "poor "mr farmer immensley, but he still had to have a moan when they eventually had to come off cos they cost "£500 quid each them did-and only new couple of years ago" (actually it was about 7 yrs ago)
billy
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The inner tubes where filled with some water to add ballast, you may recall a lot of the rims were split rims to ease tyre fitting. Good times as a young lad at harvest time. I remember one young lass and a hay stack, but that another story, gone off for a shower, back later. Regards Peter
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