Continuation Of Nitrogen Tyre Fill

[TigerFish]

@ Dave, I agree with Rob, unless you do a controlled experiment, it means nothing.

I have a similar stance to Rob, I don't really care if people use it or not in their tyres and on face value it would seem to make no difference (negatively or positively). I might use it if it were free, but it wouldn't swing me to go to one supplier over another because they had it for free or at a cost. But I do like people to have the correct info though and not be hoodwinked into a trend or gimmick that is claiming to do something it is not.

While searching the web lastnight about it, I did find some discussion going on about a test that was done comparing the deflation rate of a tyre filled with pure N2 rather than freshair (it didn't mention if it was dryed to this could've been a factor in the results). It seemed that after inflation to 35psi, and left for one year, then rechecking that the N2 tyre had lost 2psi, the air tyre had lost 3.5psi. This seemed fairly consitent across the tests. The conclusion was that given regular vehicle maintenance (i.e. checking tyre pressures regularly) it gave no appreciable gain in holding its inflation. However, it does tend to suggest that although logically/scientifically there may be nothing to support the fact that N2 lost less pressure, that in the real world it did indeed seem to hold some truth.

[VVProtocolVV]

When Clark on top gear mentioned that the new Nissan GT-R had nitrogen filled tires as factory standard, i thought he was joking, but apprantely not. Also isn't that a lexus he was trying to get past? lol

[Rob's Lexx]

interesting tigerfish.

a 1.5 psi difference is not much over a year, but it is a difference i guess. however, is that really something that needs all the marketing tosh that seems to be around?? doubt it!! i'm still utterly baffled as to any logic behind the practice and until someone can give me hard scientific facts about it, then i will remain unchanged in viewpoint.

the only thing i (and a couple prof's in my department) can think of is the reactivity of the 2 gases. obviousl;y N2 is inert, yet O2 is slightly more reactive - so there may be a possibility for some sort of oxidative decomposition of the tyre a mean there may be some pressure loss (although i'd worry about the safety of a tyre if that were the case). that said, i doubt road cars and the occasional track car will experience temperatures high enough to promote such mechanisms (unlike F1 of course) and hence negating the whole hypothesis in the first place.

[Sagitar]

i'm not saying don't get it done, i'm just saying that i don't understand any logic behind it.

No Tony, no-one would go to BOC, but i presume your nitrogen source comes from somewhere???

take it its an evacuate/refill procedure for the nitrogen fill then based on that wozza. cheers mate, just wondered thats all.

In the days when I designed aircraft hydraulic systems, we used nitrogen because it was safer. It is more inert and less of a fire risk than compressed air. Some of our systems operated at very high pressures (1500 p.s.i. plus) and were in close proximity to hydraulic fluid and fuels, so it was worth being careful. Incidentally, the characteristic that causes nitrogen not to support combustion also means that it will not support human life, so if you are going to use it, store or generate it in a well ventilated area. It is not poisonous, but it will asphyxiate you.

Bottled nitrogen can also be more convenient than carting a compressor around, with the maintenance implications, especially of water traps. In the laboratory where we assembled prototypes and tested systems we used piped high pressure nitrogen from a Battery of large bottles stored on the outside of the building.

The performance of nitrogen as a working fluid, in terms of heat transfer and the relationship of pressure, temperature and volume is essentially no different from that of dry air. Their molecular mass is very similar (the air to nitrogen ratio is about 1.03 to 1) so their thermal inertia is also very similar.

I know nothing about F1 but I would guess that their logic is not dissimilar from that of the aircraft industry.

The arguments about leakage through tyre walls appear to me to be fatuous. Such leakage rates are very low and tyres should be checked weekly. Any difference in pressure loss over such a short period due to differences in the nature of the gases will be so small as to be unmeasurable with normal equipment.

The argument that topping up with nitrogen will reduce the need for frequent checking is equally weak. If you get a slow puncture or a faulty inflation valve it wont matter a damn whether your tyre is filled with air or nitrogen.

A commercial organisation may well decide that it is more convenient to store or generate nitrogen than to run an air compressor and if I were offered a nitrogen top up at no cost, I wouldn't hesitate to accept it, but I certainly wouldn't kid myself that it would make any significant difference to the way my tyres behaved.

Perhaps the best argument that I have heard for nitrogen inflation in every-day road vehicles is that it comes with pretty green inflation valve caps . . . . .

[DJ Wozza]

wozza, you seem to be missing the point i'm trying to get at mate.

if someone is selling something that is meant to be beneficial for the buyer, then they should have a full understanding etc of why its the case.

Sorry Rob I believe you seem to be missing the point I made above.

well if it's good enough for Formula 1 for years, and where I had it done is free,

then I'm a happy bunny

Nothing was sold, it was FREE so what's the issue ? No one is asking you to have it in your Tyres or to pay for it either,

or forcing it on you. It's not like I was fed gobbledygook and loads of technical jargon etc and charged an extortionate amount or even

a very small amount. Then I could possibly see your objection, & fair enough for that. But here that simply isn't the case. There was no charge.

There is the Formula 1 association, and it was free. Job's a good 'un in my book & I'm fairly sure the majority will be very happy for exactly the

same if they were offered it in the same circumstances. I had the choice, Air or FREE Nitrogen.

[TigerFish]

wozza, you seem to be missing the point i'm trying to get at mate.

if someone is selling something that is meant to be beneficial for the buyer, then they should have a full understanding etc of why its the case.

Sorry Rob I believe you seem to be missing the point I made above.

well if it's good enough for Formula 1 for years, and where I had it done is free,

then I'm a happy bunny

Nothing was sold, it was FREE so what's the issue ? No one is asking you to have it in your Tyres or to pay for it either,

or forcing it on you. It's not like I was fed gobbledygook and loads of technical jargon etc and charged an extortionate amount or even

a very small amount. Then I could possibly see your objection, & fair enough for that. But here that simply isn't the case. There was no charge.

There is the Formula 1 association, and it was free. Job's a good 'un in my book & I'm fairly sure the majority will be very happy for exactly the

same if they were offered it in the same circumstances. I had the choice, Air or FREE Nitrogen.

I think you are still missing the point Wozza. It is nothing to do with cost, or whether to have it or not, it is the fact that people are not given the proper info. The F1 link seems to be used as some kind of selling point or one upmanship to attract a buyer to a supplier, when in reality it has NO gain. You did it yourself.........

slightly

Irrespective of the technical opinions, rights and wrongs etc , if the results are as stark acroos the board as

Dave has had on the IS350S/C then it's a no brainer.

Luckily mine were done some time ago @ WIM

.......... and came across as being superior (which may not have been your intention but that is how it sounded to me) because you had nitrogen in your tyres, why? You didn't have a clue, and when it comes down to it, for no good reason other than it was free. Which in itself is fine, but you were trying to "sell" the nitrogen fill to people as having some worth. At least you now know it doesn't have any worth and just comes down to being something you have in your tyres that deserves no bragging rights.

[Rob's Lexx]

hey up wozza,

to clarify what I meant:

its nothing at all to do with cost, or gratuity. my issue is with the fact that something should not be offerred or sold when the understanding of the supplier is lacking. i'm sure you can understand that. otherwise, i could offer people H2S gas and tell them it was a suitable replacement.

its good the service is free (hats off to WIM for that as there are many that charge up to £2 a corner!!) and the fact your happy with it is good. but in my line of work, as others, there has to be hard evidence/facts behind the process.

i would willingly have N2 filled tyres, but as sagitar said, i wouldn't kid myself that they are beter pressure holding etc etc than air (and in fact the science disproves that arguement) and therefore haven't seen the neccesity to get them done.

[DJ Wozza]

Rob,

I won't argue the technical point with you as you are I'm sure holding all the cards & knowledge in the technical area.

My real point is that I was offered it free as an alternative to air, but it wasn't sold to me, or the reason I bought new tyres

from WIM in the first place. It well may be industry hype about Nitrogen, but based only from my own experience with these

particular tyres fitted to my car that were filled with Nitrogen upon fitment, I certainly have nothing bad to say about the effect it

has had, infact no difference in the handling of the car at all (my name isn't Lewis Hamilton) other than having fresh new rubber,

and must state the pressures are holding up very well.

For me (rightly or wrongly in a technical sense) the Formula 1 association plus the fact that it was completely free made it

rightly or wrongly a very easy choice to make.

I'm not arguing the technical gas/physics issue, just purely my own un-technial observations with the set up on my car as it is now.

Now on with the next important descision, Daddy or Chips ? Hmmmmm :winky:

[Rob's Lexx]

fair enough mate, i completely see where ur coming from. there is going to be no noticeable difference between the two gasses in the tyres and you won't notice a difference. The main thing is that both are safe to use. it'd be a different kettle of fish if there was a hype regarding another poitentially lethal gas being used, for example.

what tyres you got fitted anyway matey??

oh, in response to your last question.......CHIPS!!!!

[DJ Wozza]

Dunlop 9090's with 255/40/18's on the back, very nice :D

[dave1]

Everyone on this forum has their own opinion ......so long as everyone is happy and content with their own choice does it really matter. There are much more important things in the modern world!!!!!!

[Rob's Lexx]

Everyone on this forum has their own opinion ......so long as everyone is happy and content with their own choice does it really matter. There are much more important things in the modern world!!!!!!

ur right dave, there are more important things in life, yet if we all had that attitude i'd hate to see what the world was like to live in :o

forums are good places to discuss topics that people are confused, unsure, etc etc about. there's no harm in discussion mate, you might even learn a thing or to from time to time :) :)

[TigerFish]

Everyone on this forum has their own opinion ......so long as everyone is happy and content with their own choice does it really matter. There are much more important things in the modern world!!!!!!

ur right dave, there are more important things in life, yet if we all had that attitude i'd hate to see what the world was like to live in :o

forums are good places to discuss topics that people are confused, unsure, etc etc about. there's no harm in discussion mate, you might even learn a thing or to from time to time :) :)

Ditto Rob, you have to weed out the cr*p info from the good. That's the point of the forum.

[DJ Wozza]

Makes it all the more fun so long as everyone can have the opportunity to say their piece, and if agreement cannot be found, agree to dissagree.

Just to throw the idea into the air or the cat amongst the pidgeons......

what would the effect of using Helium instead or Air or Nitrogen be ? (possible benifit being less unsprung weight ??)

[aaronabbott]

helium,nah mate makes high pitched road noise :D

[The Transporter]

Hmmmm.. I think that moisture is the real problem with air from a compressor.. Anyone who has ever had an air compressor will have had to drain the receiver tank periodically will have seen how much water has to be drained from them.... Paint sprayers have to use air driers to ensure a dry supply of air to their spraying equipment and bearing in mind that many operatives at tyre bays have to use air wrenches to make sure that they have attached your wheels tightly enough, it would seem to me that in many cases, they are not the kind of guys who would pay too much attention to the daily requirements of their air compressor... So I would suggest that you do have a high risk of them inadvertently introducing a lot of moisture to the tyre air, thus causing the wide fluctuations in tyre pressures due to temperature that has been reported.

Here is a theory on the F1 guys, and it is only a theory... Nitrogen is a handy material to have around for blowing stuff clean, non toxic (But it is an asphyxient) Non oxidising, so it is safe to use where grease and oil are to be found and allows brazing of metals where oxidation would cause a problem, relatively cheap. and is supplied in bottles (Easily transportable) with a known moisture content so that the engineers know exactly what the pressure of the tyres will be at any given temperature... IE it is the perfect mechanics gas for doing all kinds of things.. A bit like WD40 but with a heavier bottle :winky:

[Rob's Lexx]

true mate.

dried compressed air in cylinders would also have zero moisture, but does contain some o2 so may not be suited for all scenarios where oxidation may be an issue (but even then you have the issue of atmospheric oxygen causing oxidation so there is no difference).

tis all a bit sketchy, but hey ho sure there may be a thorough in depth scientific journal article regarding this in due time (here's hoping from a personal perspective)

[Rob's Lexx]

Makes it all the more fun so long as everyone can have the opportunity to say their piece, and if agreement cannot be found, agree to dissagree.

Just to throw the idea into the air or the cat amongst the pidgeons......

what would the effect of using Helium instead or Air or Nitrogen be ? (possible benifit being less unsprung weight ??)

will make the car fly.......... :lol: sorry, had to.

no seriously though, you have the basis of an argument regarding unsprung weight, but i doubt there is going to be much difference?? its an interesting one though, as there could be the potential for some sort of benefit for those on the edge of mechanical boundries etc (F! for example). the only thing with He is its a very small molecule....wonder if there would be some diffusion/porosity issues??

a bizarre thought i had (not thought it through practically before anyone shoots me down, lol) was to use something like NO2 in tyres which could potentially act as not only a pressure source but as a refrigerant. maybe a daft idea but something like that may be beneficial somewhere?? just me being over imaginative i think, lol.

[The Transporter]

Helium would leave you with four flat tyres very quickly indeed.. It is great for finding tiny leaks in air conditioning systems but the detectors cost the earth... I'll stick with using Nitrogen and a sniff of pipe freezer.

[Mike_B]

Helium would be a terrible gas for inflating tyres - the atoms are so small they find their way out of the tiniest gaps; and would have no problem going through the side of the tyres.

This is why diving watches have helium escape valves, underwater and under high pressure, helium dissolved in the seawater just waltzes straight through the seals that keep the water out, then when you come up the helium pressure inside the watch can be high enough to blow it apart...

[Mike_B]

a bizarre thought i had (not thought it through practically before anyone shoots me down, lol) was to use something like NO2 in tyres which could potentially act as not only a pressure source but as a refrigerant. maybe a daft idea but something like that may be beneficial somewhere?? just me being over imaginative i think, lol.

Just a touch imaginative - unless you have a compressor and evaporator, they won't have any cooling effect at all. The gas used in refrigeration systems is irrelevant, so long as it can change from gas to liquid at reasonable pressures and isn't too reactive.

No-one seems to have mentioned Boyle's Law yet, which is the applicable law of physics here. Boyle’s law states that at constant temperature, the absolute pressure and the volume of gas are inversely proportional. Therefore, since the volume inside the tyres is fixed, as the temperature goes up, so does the pressure. This isn't going to change by having the presence or absence of 20% oxygen in the tyre alongside the nitrogen, and in the everyday sorts of temps and pressures we are talking about in a car wheel, Boyle's Law is going to apply more or less perfectly.

If there was any liquid water inside the tyres though, then when that gets hot and evaporates (highly likely on a racetrack, my bike tyres go up to about 80C on track, and F1 tyres go beyond 100C) the pressure will increase by more than Boyle's law would predict, leading to a sharply increased pressure inside the tyre. Using pure nitrogen, it is unlikely that any water would be present leading to a more consistent temp/pressure gradient.

See Link for F1 references.

[Rob's Lexx]

a bizarre thought i had (not thought it through practically before anyone shoots me down, lol) was to use something like NO2 in tyres which could potentially act as not only a pressure source but as a refrigerant. maybe a daft idea but something like that may be beneficial somewhere?? just me being over imaginative i think, lol.

No-one seems to have mentioned Boyle's Law yet, which is the applicable law of physics here. Boyle’s law states that at constant temperature, the absolute pressure and the volume of gas are inversely proportional. Therefore, since the volume inside the tyres is fixed, as the temperature goes up, so does the pressure. This isn't going to change by having the presence or absence of 20% oxygen in the tyre alongside the nitrogen, and in the everyday sorts of temps and pressures we are talking about in a car wheel, Boyle's Law is going to apply more or less perfectly.

If there was any liquid water inside the tyres though, then when that gets hot and evaporates (highly likely on a racetrack, my bike tyres go up to about 80C on track, and F1 tyres go beyond 100C) the pressure will increase by more than Boyle's law would predict, leading to a sharply increased pressure inside the tyre. Using pure nitrogen, it is unlikely that any water would be present leading to a more consistent temp/pressure gradient.

See Link for F1 references.

mate, think u need to read the thread from the start.

i've mentioned boyles law/ideal gas equation as well as molecular dynamics and radii effects.....

but yes, thinking about it, the NO2 idea wasn't thought out well enough.....hmmmm, back to the drawing board, lol.

[TheDon]

well the plus's and minus are all there.. the idea of a tyre that would take longer to drop in pressure appeals to me... the pub talk also appeals.. the cost... appeals.. the practicals.. couldnt care.. would like to try it out on my ZX12R.. that would be interesting as you can seriously get that tyre warm....

also just a thought... to control speed... could someone not come up with a gas that would explode at 71mph.... then fit it to BMW's so that when they charge down the motorway they explode and dissable the car and driver from moving... that would be sweet...

also... im sure the ex mclaren F1 head mechanic guy could tell you the "exact" reason why ferrari used nitrogen...

[Vyker]

A good read!

*Vyker learnt something new!

[The Transporter]

also just a thought... to control speed... could someone not come up with a gas that would explode at 71mph.... then fit it to BMW's so that when they charge down the motorway they explode and dissable the car and driver from moving... that would be sweet...

Good grief!! The Bavarians are light years ahead of you there.... Rather than restricting speed, they restricted range... Ask any mid nineties BMW driver about his Nikasil problem. Don't let him kid you that he is using patches to cure it

Modern times call for modern ways to gum up the plumbing, so BMW introduced the Piedrive.. A system so confusing that most drivers never get to leave their own driveway

:winky: