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Nitrogen Filled Tires?

Discussion in 'Gen 2 Prius Main Forum' started by jonm, Jun 23, 2005.

  1. Sufferin' Prius Envy

    Sufferin' Prius Envy Platinum Member

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    Had anybody ever experienced premature failure of a domestic automobile prior to the early 70's???

    Cars from Japan challenged that status quo and ate Detroit’s lunch in doing so.

    Nitrogen is now challenging the car tire inflation status quo as did the Japanese with car quality. This time one of the contenders is air. Free air! Who would pay for air? Or, more precisely . . . “Tire Care Airâ€

    If you don’t think there will be a tire inflation status quo change in the not to distant future, just consider bottled water. If you told someone back in the early ‘80s that in near future people will pay twice as much for small bottles of water than what they pay for gasoline, you would have been laughed at hysterically. Nowdays there are hoards of human lemmings slurping away on what is sometimes nothing more than store bought filtered municipal tap water.

    Why?
    - Perception. -

    But then, most people perceive chilled water from a drinking fountain as higher quality water than that from your tap at home . . . (never mind the decreased flow when someone flushes a toilet in the public bathroom near the public drinking fountain you are drinking from!)

    If nitrogen in my tires will help them maintain proper inflation for longer periods and that nitrogen can be had for free, such as at Costco - I’m all for it. If someone wants to charge you a premium for the stuff, you may want to consider saving the money and applying it to your next tire purchase.
     
  2. sailorkid

    sailorkid New Member

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    A few observations on Nitrogen filled tires:
    1. yes, Costco uses it for free.. I buy my tires at Costco so there is no identifible cost. :D
    2. yes, it helps to maintain a better regulated PSI for a Tempature change..I live in Salt Lake City and commute to Park City daily... I use to adjust a cold tire's psi when there was a 40 degree change in the daily temp(about 5 PSI per tire).
    3. I agree with the posts that under normal daily usage, tread life will kill a tire quicker than rot, but for years I had a sailboat trailer used very little and am not use if sitting, sun or O2 killed the sidewalls, as the treads looked new.
     
  3. jeepien

    jeepien Member

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    The nitrogen issue has been talked to death on some of the technical forums.

    I'm not inclined to type all the molecular physics discussion over again, but the bottom line is:

    Nitrogen has no intrinsic theoretical advantage over air.

    The weakest of the claims is that it does not expand as much when heated. Anyone who has taken high school chemistry or physics will recall the formula PV=nRT which applies to all gases equally, at relatively low pressures (a few atmospheres or less) and relatively high temperatures (a few hundred kelvins or more).

    The oxygen reactivity is not an issue. Has anyone ever seen the inside of a tire that has been ravaged by oxygen? Me neither. Besides, the outside is also exposed to oxygen, plus ultraviolet light, and that doesn't get ravaged either. And nitrogen is slightly MORE likely to diffuse through rubber than oxygen is, but neither one diffuses to any significant degree.

    There are only two practical advantages and neither of them have anything to do with any "magic" properties of nitrogen. The first is that nitrogen is likely to be dry (to contain little or no water vapor) because of how it's produced.

    Water vapor does not behave like an ideal gas because if its high boiling point (373 K). This fact may be what's behind the rumors that air expands more when heated. The difference, however, is fairly negligible. If it were significant, it would still not be necessary to use to nitrogen, as ordinary air could be easily and cheaply dried to remove the water vapor before compression. It's not, because the payoff is so small.

    The other advantage is that nitrogen can easily be transported in highly pressurized liquid form, and turned to pressurized gas in large quantities at the point of use, using a simple regulator valve. No compressor is needed. The overall cost of doing this is greater than simply using an air compressor, but if portability is an issue, such as at airports and racetracks, it makes economic sense.

    In this application, the reason nitrogen is used in preference to any of the other gases available this way is not due to any purported superior properties of nitrogen except one: nitrogen is by far the cheapest.
     
  4. Steve Zettel

    Steve Zettel New Member

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    Thanks, Jeepien. I appreciate the voice of reason!

    Steve Zettel
     
  5. kirbinster

    kirbinster Member

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    I would think a small amount of water inside the tire might be a positive thing. Wouldn't it help balance a tire that is slightly out of balance as it spins.