| Frozenr6 |
07-11-2010 09:20 PM |
where to start with this one I work in an industry where we make siginifcant investment in tires about 30 million a year and we dont use nitrogen in our tires. And we have examined it at length.
1) The stability over temperature argument - is not that simple, this goes to why race teams use nitrogen. It is not actually stability that they are chasing it is the absolutely predictable rate of expansion dervied from not having any moisture in the tire. When you are looking at .5 pounds of pressure making a handling difference being able to truly cold fill a tire and know what the hot temperature is going to be is a must. Partial myth there due to no applicability to road cars.
2) The tires will run cooler - current advances in tire temperature pressure and temperature monitoring have born this to be a myth, as long as the inflation of both tires is the same there is no measureable difference.
3) Why do airplanes use nitrogen - primarily because at levels exceeding 94.5% purity nitrogen is inert meaning that the tire is less likely to explode due to pyrolysis occuring within the tires.
4) The fuel economy improvement argument - this is predicated on maintaining tire pressure correctly and is a flawed argument, in that if you dont measure pressure pre-nitrogen you will not with nitrogen either, in anecdotal trending it would indicate that those running nitrogen have a false sense of security on their pressures.
5) Corrosion of belts and interior carcass - ding this is true...... but tell me when was the last time that you wore out the interior of the tire before the tread?? I have never done that myself. This is further hampered by what some others have mentioned, eliminating a small amount of moisture from the inside does nothing to mitagate all the pesky oxygen, moisture and the bonus prize UV from attacking the outside of the carcass.
This was primarily aimed at long haul truck applications that retread non steering axle tires and ensuring that the case was reuseable, but in recent effort one of our major tire providers did a controlled study on their truck fleet and could not demonstrat a cost benefit to using nitrogen on their own fleet.
The basics need to be understood, in order to have meaningful inflation with nirogen you must have a greater than 99% pure source. This is the only way to ensure that the tire can be inflated to 96-98% pure nitrogen and that is predicated on being able to fill the tire, deflate and re-inflate to displace the O2 already in the tire at atmospheric pressure. This holds true for every tire that someone needed to top of with compressed air due to lack of facilities.
To test the level of nitrogen in a tire you need to actually measure the level of Oxygen in the tire and surmise from there.
We can start a whole different debate on the processes used to deliver compressed nitrogen and their effectiveness in another topic later if need be.
Cliffs Notes: if you maintain your tire pressure correctly anyway Nitrogen is a good way too waste your money. I would not pay ever to have my tires filled with Nitrogen.
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