Yah, what James said....
Rascal
-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of
james.zito@ps.ge.com
Sent: Friday, July 30, 2004 8:16 AM
To: dakota-truck@dakota-truck.net
Subject: Re: DML: Guess, mpg
> I was at Costco the other day...they had a sign up
> about putting nitrogen instead of air into your tires.
> I don't know if it was free or an "add on". Anyone
> know the merits, if any, of nitrogen over regular old
> generic air?
My brother is a Tire Center Manager for Costco and he was telling me about
this the other day. I thought it sounded weird at first, but it makes sense
now that he explained it. Due to the physical properties of Nitrogen, it
won't bleed out through the tire, thus keeping your tire pressure more
constant, less refilling. It also won't fluctuate as much in the hot/cold
like regular air does. Don't know if it's free or not, but I could check.
- -Dave
Ok guys, here is my take on it, generic air is 79% N2 21% O2 and less than a
% of other gasses (I know that this adds up to 101 but the 79 and 21 are
also padded just a little). N2 is a slightly smaller molecule than 02 (N
has atomic # of 7 and O has atomic # of 8 atomic weights are roughly double
the numbers).
Based on the basic composition of air I don't think there would be any real
difference on the bleed out except for the <1% that is made of really lite
gasses. Although the fact that N2 is smaller than O2 would lead me to
believe that it would bleed out just a tiny bit faster than regular air.
Now you do save about 2 grams per mole of N2 over O2 so I suppose you would
end up with a tire that is maybe enough liter that you could detect it.
(This is the reason that some racers fill their tires with He reduces the
mass considerably.)
Jim
just chiming in to muddy the waters.......
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