You misunderstand me, I agree with you..... at all (though the statement about molecule size is stretching it a bit). My point is that for Joe Average the chances of having a tyre which contained ONLY nitrogen are as high as six numbers coming up so to suggest that adding nitrogen to a standard car tyre is of any benefit is nonsense and just a big con and way of extracting hard earned money from him. In other words it makes no logical sense. How many tyre fitters have a nirogen pure environement - what!!!!
It does work,I've seen it with my own eyes over a period of a couple of years.
As I said,the system we had was removed due to low demand,but the customers that used all said that it was of benefit,especially for keeping the pressures constant.I have seen tyres using this keep their pressure for 12 months+!.
You had to be a little careful what cars you used it in though as we had problems with small,light cars being very skittish.....
Actually, that's not too bad considering most petrol stations charge to use air now. Still a bit to much hassle thoughI THINK we used to charge a pound a tyre,plus VAT.
It was costing more a month to maintain than we were earning,so unfortunately it had to go.Just for the record,we had a Uniflate system.
Cheers Noel.Very interesting Pat - and technical too. I used to work at repairing air compressors in garages, etc and when I seen the amount of water in the systems I couldn't help wonder what affect it would have on tyres. The owners wouldn't even bother to drain the water separators even when fitted. The expansion rates of air with a high humidity content is significantly different than that of a pure dry gas. In my eperience most tyre compression equipment doesn't even have decent water separators fitted. The main advantage of a dry gas would be that tyre presures would be less prone to changes in pressure when there are changes in either the tyre or ambient temperature. For it to have a good effect the tyre needs to be purged of air first. I can fully understand the need to use nitrogen on aircraft as their tyres can be subjected to fast changes in ambient temperature and humidity - antything from - 40C - to + 40C sometimes within minutes.
Most of these systems take compressed air and pass it through a series of carbon filters. A membrane then separates the Nitrogen from the other gasses. They aren’t so keen on damp air though, so you should have had a good separator or preferably a dryer in line. What I think Noel was really referring to was the amount of water than can be generated in a compressor, if it's not maintained properly that water gets in the tyres........I must admit,the system we had ran off the compressor but had it's own sealed box of tricks.I'm not sure what was in there,but I suspect there were some very thirsty Pixie's in there drinking all the mositure from the air.:d
That's what I think anyway!.