Tyre inflation with Nitrogen

[Keith Lard]

Up to 25%. Which includes any values from 0-25, so they're not lying...

Yes, but that then implies on at least one vehicle it has resulted in a 25% increase, even if others were lower. Shame the website shows no evidence of anything of the sort!

[Lady Elanore]

http://www.uniflate....-tyre-inflation

Well we all believe that don't we. What a splendidly scientific demonstration of the benefits of nitrogen. Just look how quickly my air-filled tyres will deflate. Better stop every 100 feet or so to check the pressures then.

Case for the advertising standards methinks!!!

If you apply my above theory you will see this shouldn’t be able to happen. After the first ‘deflation as all the oxygen has leaked out you will be left with aboth80% of the original gas (the nitrogen). I am sure some clever chap can work out the resultant tyre pressure using Boyles laws or something like that. Anyhoo, you will then once again fill your tyre up with air. But this time, only adding approx 20% of the original amount to replace the lost oxygen. So very roughly speaking you will have 20% of 20% oxygen in your tyre, ie only 4% of you tyre will have oxygen in it, the remainder will be almost 96% nitrogen and so on. I doubt losing 4% of the gas in your tyre will cause it to run at half the pressure, but even if it did a couple of refill will give you pretty much 100% nitrogen tyres anyway

Obviously there are a few other gases in small amounts in our atmosphere and different gases will compress at different rates depending on temp etc, but the rough figures surely show that the whole premise is a little out of proportion.

Edited 2 November, 2010 by Lady Elanore

[bahnstormer vrs]

If you apply my above theory you will see this shouldn’t be able to happen. After the first ‘deflation as all the oxygen has leaked out you will be left with aboth80% of the original gas (the nitrogen). I am sure some clever chap can work out the resultant tyre pressure using Boyles laws or something like that. Anyhoo, you will then once again fill your tyre up with air. But this time, only adding approx 20% of the original amount to replace the lost oxygen. So very roughly speaking you will have 20% of 20% oxygen in your tyre, ie only 4% of you tyre will have oxygen in it, the remainder will be almost 96% nitrogen and so on. I doubt losing 4% of the gas in your tyre will cause it to run at half the pressure, but even if it did a couple of refill will give you pretty much 100% nitrogen tyres anyway

Obviously there are a few other gases in small amounts in our atmosphere and different gases will compress at different rates depending on temp etc, but the rough figures surely show that the whole premise is a little out of proportion.

I really like this explanation! Well explained and entirely logical.

Speaking from practical experience on this subject, I took over one of our Company cars a few weeks ago that had been in use for four months from new and the pressures were 0.5bar lower than they should have been; I doubt the pressures had been checked in this time.

Running my cars as I do with nitro in the tyres and checking them every 2 - 3 weeks I find that I virtually never have to add any air.

OK; one has to take some of Uniflate's claims with a pinch of salt but from my experience I know/believe nitro in my tyres works; so I'll stick with it.

PS> Phew; I never believed this would be such an emotive subject.

Edited 2 November, 2010 by bahnstormer vrs

[eccleshill]

ie only 4% of you tyre will have oxygen in it, the remainder will be almost 96% nitrogen and so on.

Only 4% of the tyre has oxygen! That explains why the tyre only goes flat at the bottom

[EdmundBlackadder]

Bahnstormer, emotive but still not as disputed as using fog lights at night which still must hold the title for "guaranteed to bring about wild rants". I also can't believe that we have got this far into the thread and no one has thrown a helium gag into the mix. I have been trying to think of a witty helium comment, squeaky voice or tyres lifting off, for two days now but have had to admit defeat.

[EdmundBlackadder]

Only 4% of the tyre has oxygen! That explains why the tyre only goes flat at the bottom

It may not be helium but that will do for me

[eccleshill]

PS> Phew; I never believed this would be such an emotive subject.

Nothing personal - but you have to admit that the link you gave is a pretty funny site

But really - I have been driving for 35 years and over that time have never filled my tyres with anything but air. The only time I have ever had pressure loss the explanation has been a puncture, badly fitted tyre, damaged rim, porous alloy wheel or cold weather. Never has the cause been diffusion of gas through the tyre. As I have said before - you will lose more air checking the pressure every week than you will lose through diffusion.

I once had an extra spare wheel with an unused tyre sitting in my garage untouched for at least 4 but probably more years; a friend asked if he could have it - I checked the pressure - it had lost no more than a couple of pounds - I remember being amazed at the time.