Filling tyres with nitrogen ... some data ...

rockylizard · Guru

Filling tyres with nitrogen ... some data ...

jules47 · The Happy Helper

But can you get it the local garage?

JA2340 · Senior Member

Have had a read of the article, and cannot understand why they consider this statement to be in any way factual.
"thats because the oxygen content oxidises faster than nitrogen" My chemistry teacher would have a pup! Oxygen does not, and CANNOT oxidise! The term "oxidise" involves the reaction of an element with oxygen, so Oxygen reacts with itself to form "oxygen oxide"? They've gotta be kidding!

And, as noted early in the article, the air that we breathe is mainly Nitrogen, so what's the big deal? Simply a con, foisted on a gullible populace by manufacturers trying to get us to part with our hard earned!

hako · Guru

Fill 'em with hydrogen...lighter than air so the whole car weighs less = better fuel economy. Hydrogen is also a superior coolant so use it in the cooling system as well.

Regards

Daryl620 · Veteran Member

Bang biggrin

rockylizard · Guru

Gday...

Given absolutely not a single scientific bone in my sad, ole body .. I visited Mars or Venus or some other really foreign place and found this -

https://chemistry.stackexchange.com/questions/59465/can-we-oxidize-oxygen

Can anyone translate ?

Cheers - John

-- Edited by rockylizard on Saturday 24th of March 2018 10:08:30 PM

dorian · Guru

http://www.thefreedictionary.com/oxidation

1. The combination of a substance with oxygen.
2. A reaction in which the atoms of an element lose electrons and the valence of the element is correspondingly increased.

2. A chemical reaction involving loss of electrons.

http://www.thefreedictionary.com/reduction

a. A decrease in positive valence or an increase in negative valence by the gaining of electrons.

A chemical reaction in which an atom or ion gains electrons, thus undergoing a decrease in valence.

This statement should explain the confusion between oxygen and oxidation:

Oxygen takes electrons from whatever it is oxidizing, so chemists also use the word oxidation to describe what happens to any substance that loses electrons to another substance.

So if an oxygen atom were to lose an electron to another atom, then it would be oxidised. In reality this would require an enormous amount of energy, so it would not occur in practice.

In short, the reference to oxidation in that article is nonsense.

Dickodownunder · Guru

So now that some have totally discredited Rockys article, there was reported that a very large Australian long haul transport company used to use nitrogen in the steer tyres of their fleet.
Their claim was that the tyres ran cooler than with air and there was less chance of a tyre failure than with air alone in the tyres.
For those that may not be familiar, a steer tyre failure can be catastrophic in a heavy vehicle at speed.
I bought a Caravan last August and it reportedly came with nitrogen in the tyres.
Checking pressures has revealed that those pressures are exactly the same as the day I took delivery.

Is nitrogen better than straight air??
I dont know but maybe someone experienced with tyres may come on with factual information.

iana · Guru

Our van purchased in 2015 has nitrogen in the tyres, to date I have not had to inflate the tyres, seems hey work for us.

dorian · Guru

Dickodownunder wrote:
So now that some have totally discredited Rockys article,...

Nobody has totally discredited the article, only the nonsensical claim that "the oxygen content oxidises faster than nitrogen". In fact the article cites factual evidence from a study conducted by the US National Highway Traffic Safety Administration.

-- Edited by dorian on Sunday 25th of March 2018 08:44:19 AM

Jaahn · Guru

Hi smile

Hmmm I bought a house made of wood 35 years ago and it is still standing so that proves wood is good hmm hmm probably the best really biggrin

That sort of argument is ??? I believe nitrogen is probably optimum for tires but really would I pay for it NO NO NO. As the air is 78% nitrogen you get it anyway, mostly. The oxygen does oxidise the tires and that is a worry if you leave them on for 50 years or so. Or run so hard they achieve 100degs regularly. Hmm, stop doing that. So where is the problem. Nowhere except perhaps a bit of water vapour in the compressed air you get. That gives a bit more variability in the pressure with temperature change. So pump 'em up out in the outback in the dry air if you think of it ! aww

Hydrogen is no good as it is such a small molecule it leaks easily out of any container quickly. So Hydrogen cars will be a worry if people park near you ? confuse

Jaahn

dorian · Guru

The study found that after 90-days the 99% pure nitrogen-filled tyres lost around 1.39% of pressure/month while the air-filled tyres lost double that at 2.13%/month. However, the study found that if, after the 90 days the air-filled tyre was again filled with air its pressure drop over another 90 days would fall to 1.59%. This is because while the oxygen content in the air mixture was oxidising (sic) in the tyre, the nitrogen content remained static but increased when the tyre was topped up. 'The approximate predicted inflation pressure loss rates for the air-inflated tires, now containing 85 percent N2, would be 1.57 percent/month (0.94 psi/month)', the study found.

This would suggest that simply refilling your tyres with air would eventually result in a nitrogen rich environment inside the tyre.

As for the "oxidising" claim, could the author be suggesting that the oxygen depletion/dilution is the result of a chemical reaction with the rubber rather than simple leakage???

dogbox · Guru

Jaahn wrote:

Hi
Hmmm I bought a house made of wood 35 years ago and it is still standing so that proves wood is good probably the best really
That sort of argument is ??? I believe nitrogen is probably optimum for tires but really would I pay for it NO NO NO. As the air is 78% nitrogen you get it anyway, mostly. The oxygen does oxidise the tires and that is a worry if you leave them on for 50 years or so. Or run so hard they achieve 100degs regularly. Hmm, stop doing that. So where is the problem. Nowhere except perhaps a bit of water vapour in the compressed air you get. That gives a bit more variability in the pressure with temperature change. So pump 'em up out in the outback in the dry air if you think of it !
Hydrogen is no good as it is such a small molecule it leaks easily out of any container quickly. So Hydrogen cars will be a worry if people park near you ?
Jaahn

sounds good

dorian · Guru

Well, I finally did what I should have done at the outset -- read the laboratory test report.

The Effects of Varying the Levels of Nitrogen in the Inflation Gas of Tires on Laboratory Test Performance:
http://www.nitrofillnow.com/documents/NHTSA_2009_Nitrogen_Inflation_Study.pdf

In the 90-day static laboratory test, the inflation pressure loss for new tires inflated with nitrogen was approximately two-thirds of the loss rate of new tires inflated with air. Similar differences between nitrogen and air permeation rates in new tires were found under dynamic, loaded laboratory roadwheel testing. An analysis of oxygen levels in the inflation gas of 76 tires that were currently in service on passenger vehicles, and which were all originally inflated and topped-off with air (21% O2), showed that the inflation gas dropped to an average of 15 percent O2 after about three years of service. This can be attributed to the faster diffusion rate of oxygen through the tires relative to nitrogen during on-vehicle service, which increases the percentage of nitrogen in the tire cavity to well above the 78 percent N2 in normal air. Therefore, barring tire punctures, deflation, etc., the relative benefits of nitrogen versus air inflation on pressure loss rate will reduce over time. The laboratory rolling resistance of new tires was tested at two different laboratories, using air or nitrogen inflation, and capped or regulated pressure. Inflating tires with nitrogen in place of air had no direct effect on laboratory rolling resistance performance. To evaluate long-term durability, new tires were broken in, inflated with air, nitrogen, or the standard (50/50 N2/O2) inflation gas, subjected to accelerated oven aging for five weeks at 65°C, then subjected to a 35.5-hour roadwheel durability test. All tires inflated with nitrogen (1 to 5% O2) or air (21% O2) passed the oven aging and road-wheel durability test sequence without failure. When the same tire models were oven aged with the standard 50/50 N2/O2 inflation gas, some exhibited premature failures on the roadwheel test, suggesting that oxidation had a deleterious effect on roadwheel durability.

The primary result expected from nitrogen inflation is to enhance retention of tire pressure over time. Though inflation with nitrogen is not a substitute for regular pressure maintenance, the closer a tire operates near its recommended pressure, the less the penalties of underinflation such as rolling resistance loss, premature wear, and possible damage to the tire from over-deflection (overheating). Additionally, there is a strong scientific basis for concluding that reducing the oxygen content of the inflation gas will reduce the internal thermo-oxidative degradation of the tire, which may aid in retention of long-term durability.

Basically ...

2/ oxygen, in the presence of heat, chemically degrades the rubber.

RustyD · Guru

The article is not discredited. I think oxygen oxidising is referring to reacting / causing oxidisation with the rubber in the tyre. The item just confirms that nitrogen is tyres is a waste of money for Joe Average.

e.g. Oxygen oxidises iron to form iron oxide. Iron is oxidised by oxygen to form iron oxide. It's how you put it.

dogbox · Guru

so if it is free bonus but not worth paying for ?

RustyD · Guru

dogbox wrote:
so if it is free bonus but not worth paying for ?

Yep.

Jaahn · Guru

dogbox wrote:
so if it is free bonus but not worth paying for ?

Yes ! smile

PS Racing cars use it because they want every 0.01% gain they can get. And racing tires barely hold the 'air' in anyway. Trucks use it because their tires are a real running cost and they might see a small gain there in a big company and some safety gain perhaps.

A cyl of nitrogen is cheap as chips so why not. Possibly cheaper than running a compressor and very dry gas too. But these advantages seem a bit remote to a GN on the road.

Jaahn

-- Edited by Jaahn on Sunday 25th of March 2018 02:15:20 PM

hako · Guru

I reckon if there is a buck in it you can prove anything, and if you believe Wikipedia, in the article on tyres it says:

Some drivers and stores inflate tires with nitrogen (typically at 95% purity), instead of atmospheric air, which is already 78% nitrogen, in an attempt to keep the tires at the proper inflation pressure longer.[53] The effectiveness of the use of nitrogen vs. air as a means to reduce the rate of pressure loss is baseless, and has been shown to be a bogus marketing gimmick.

JA2340 · Senior Member

dorian wrote:
So if an oxygen atom were to lose an electron to another atom, then it would be oxidised. In reality this would require an enormous amount of energy, so it would not occur in practice.

In short, the reference to oxidation in that article is nonsense.

And puts the rest of the article under suspicion of being the same! My opinion, FWIW.

Tony Bev · Guru

I have seen some large ball mills operating 24/7 which are supported by inflated tyres
I can see the benifit of having these tyres inflated with nitrogen, so that the temperature changes do not alter the ride height

The Formula One racing cars have nitrogen inflated tyres
I can see the benifit of having these tyres inflated with nitrogen, so that the temperature changes do not alter the ride height too much

For me (a typical Grey Nomad), travelling within the legal speed limits, I see no need for nitrogen in my tyres

JA2340 · Senior Member

dorian wrote:
Well, I finally did what I should have done at the outset -- read the laboratory test report.

The Effects of Varying the Levels of Nitrogen in the Inflation Gas of Tires on Laboratory Test Performance:
http://www.nitrofillnow.com/documents/NHTSA_2009_Nitrogen_Inflation_Study.pdf

In the 90-day static laboratory test, the inflation pressure loss for new tires inflated with nitrogen was approximately two-thirds of the loss rate of new tires inflated with air. Similar differences between nitrogen and air permeation rates in new tires were found under dynamic, loaded laboratory roadwheel testing. An analysis of oxygen levels in the inflation gas of 76 tires that were currently in service on passenger vehicles, and which were all originally inflated and topped-off with air (21% O2), showed that the inflation gas dropped to an average of 15 percent O2 after about three years of service. This can be attributed to the faster diffusion rate of oxygen through the tires relative to nitrogen during on-vehicle service, which increases the percentage of nitrogen in the tire cavity to well above the 78 percent N2 in normal air. Therefore, barring tire punctures, deflation, etc., the relative benefits of nitrogen versus air inflation on pressure loss rate will reduce over time. The laboratory rolling resistance of new tires was tested at two different laboratories, using air or nitrogen inflation, and capped or regulated pressure. Inflating tires with nitrogen in place of air had no direct effect on laboratory rolling resistance performance. To evaluate long-term durability, new tires were broken in, inflated with air, nitrogen, or the standard (50/50 N2/O2) inflation gas, subjected to accelerated oven aging for five weeks at 65°C, then subjected to a 35.5-hour roadwheel durability test. All tires inflated with nitrogen (1 to 5% O2) or air (21% O2) passed the oven aging and road-wheel durability test sequence without failure. When the same tire models were oven aged with the standard 50/50 N2/O2 inflation gas, some exhibited premature failures on the roadwheel test, suggesting that oxidation had a deleterious effect on roadwheel durability.

The primary result expected from nitrogen inflation is to enhance retention of tire pressure over time. Though inflation with nitrogen is not a substitute for regular pressure maintenance, the closer a tire operates near its recommended pressure, the less the penalties of underinflation such as rolling resistance loss, premature wear, and possible damage to the tire from over-deflection (overheating). Additionally, there is a strong scientific basis for concluding that reducing the oxygen content of the inflation gas will reduce the internal thermo-oxidative degradation of the tire, which may aid in retention of long-term durability.
Basically ...
1/ oxygen leaks faster than nitrogen, and ...
2/ oxygen, in the presence of heat, chemically degrades the rubber.

And, of course, my van's tyres are currently in a "static" situation (unfortunately!), so likely leaking oxygen as we speak. The article did not appear to go into the effects under conditions of actual use! That would have been less than empirical, and would have introduced factors that the study could not possibly have allowed for.

So, the theoretical bar has been set, and they are welcome to continue the experiment into the effects under static conditions.

There is a significant difference between "rubber may be oxidised by the oxygen in the air" and "oxidation of the oxygen". I don't have a problem with the former, it is more likely than not, but DO have a problem with the statement that the article made about oxygen oxidising. also have a problem with the very long bow drawn about the benefit of having N2 filled tyres wrt the "oven aged" 50/50 N2/O2 tyres.

Anyway, bottom line is that I will not be using N2 (apart from the standard 70% mix from the atmosphere) as I don't get to temps that would require a non-explosive mix.

Kiwoz · Veteran Member

A little something that is possibly being overlooked here is 'air volume' and the benefit to larger tyres. What seems like a good while ago, on another island, I was made aware of the fact that motorscrapers on hydro-power developments were gaining great benefits from using Nitrogen in the tyres. Nothing to do with tyre degradation but purely overpressure. Issues were from tyres fitted on nightshift, would go bang when the daytime/operating temps. struck home. I guess this and TonyBev's senarios are quite different from what's been bandied around here so far but mebe clearup a few facts.

IAN zzz · Veteran Member

I've tried it once. But that was it for me. Couple of reasons:

- Puncture repair in the outback - did not have Nitrogen on hand, and if I had refitted that tyre I would probably have had an imbalance in pressures between front and rear at usual speeds - not ideal.

- I often deflate and inflate tyres on my wagon and van depending on conditions. I figured it was just easier to use my compressor ... rather than carry Nitrogen :)

Stay safe

dorian · Guru

IAN zzz wrote:
I've tried it once. But that was it for me. Couple of reasons:

- Puncture repair in the outback - did not have Nitrogen on hand, and if I had refitted that tyre I would probably have had an imbalance in pressures between front and rear at usual speeds - not ideal.

Pressure is pressure, not volume or mass. You can achieve the same pressure by filling your tyre with nitrogen or air (or helium or any other gas).

As for mass, the atomic mass of a nitrogen molecule (N2) is 28 while the atomic mass of an oxygen molecule (O2) is 32. Air consists of 79% nitrogen and 21% oxygen.

Therefore the atomic mass of an average air molecule is ...

(0.79 x 28) + (0.21 x 32) = 28.84
The difference in mass between air and nitrogen is therefore 2.9%

More importantly, the difference in mass between an air filled tyre and a nitrogen filled tyre is probably 0.00001%.

Phillipn · Guru

hako wrote:
Fill 'em with hydrogen...lighter than air so the whole car weighs less = better fuel economy. Hydrogen is also a superior coolant so use it in the cooling system as well.

Regards

What a load of BS!

dorian · Guru

Phillipn wrote:
hako wrote:
Fill 'em with hydrogen...lighter than air so the whole car weighs less = better fuel economy. Hydrogen is also a superior coolant so use it in the cooling system as well.

Regards
What a load of BS!

It's sarcasm.

diggerop · Senior Member

I think most of the oxygen has leaked out by now.

Aus-Kiwi · Guru

In airiplanes where temps vary big time itâs almost compulsory. Any condensation or moisture in tyre can be disastrous ! On race cars where tyre pressure and milliseconds count ? Yes ., But for general public on daily driver or van itâs a wast of time !! Plus tyre pressure to a point has a wide envelope pressure wise . Ok too much you wear center tread . Too low ? It can over heat . So keeping a check on higher pressures if anything is far safer .

Phillipn · Guru

dorian wrote:
Phillipn wrote:
hako wrote:
Fill 'em with hydrogen...lighter than air so the whole car weighs less = better fuel economy. Hydrogen is also a superior coolant so use it in the cooling system as well.

Regards
What a load of BS!
It's sarcasm.

No, the truth.