Les, I spent over 300k to be able to increase the local air to enough
pressure to fill my MH tires. Among friends it's produces about 80%
Nitrogen and the water vapor content is very low. Works great for me:-)
A few month's back we went though this discussion. Someone finally
referenced The Car guys on PBS who said paying for pure Nitrogen was a waste
of money. Here is one of the Car Guy articles on Nitrogen.
Dear Tom and Ray:
I recently heard about filling tires with nitrogen gas to maintain pressure
and lengthen tread life. Since the air we breathe is 78 percent nitrogen, I
fail to see how much benefit you actually get from changing from air to
nitrogen. The creators of this are selling it as a safety issue. I'd hate to
be scammed into paying for premium air. I'm seeing Starbucks-style gasoline
boutiques in our near future. What do you guys think? -- Rob
Beat up old car <http://www.cartalk.com/common/images/yellowcar2.gif> TOM:
My first thought is, I'm putting all my money into Airbucks!
RAY: Like many sales pitches, the nitrogen idea has a molecule of truth in
it. You're right that normal atmospheric air is about 80 percent nitrogen
already. The rest is made up of oxygen, argon, water vapor, cat dander, bad
breath and coal-plant particulates. And the truth is, atmospheric air is
absolutely good enough for filling your tires.
TOM: Pure nitrogen has a couple of advantages. One is that it expands and
contracts less under hot and cold temperatures than a mixture of nitrogen,
oxygen and water vapor. That can be an advantage if you're in, say, a race
car driving at 200 mph around a track for 500 miles -- where tiny
differences in tire pressure and handling can really matter.
RAY: Nitrogen also doesn't support combustion like oxygen does. So it's
unlikely to fuel a fire started in some other part of the car if a tire
explodes. Of course, there's already plenty of combustible air all around
the car, regardless of what's in the tires.
TOM: And finally, both the oxygen and the small percentage of moisture in
the atmospheric air can contribute to degradation of the inside of your
tires and wheels. But think about it: The outsides are exposed to the air
all the time, so what are you worried about the insides for?
RAY: So, none of these advantages is important to the average driver. They
just don't matter enough to ever think about. And they certainly don't
matter enough to pay for, Rob.
So the question why do race teams use Nitrogen, because that's what is in
the tanks to drive the air tools. Remember they change tires every few 100
miles on a Sunday afternoon. We try to get 7 years out of the tires. Very
few of us will ever wear out our MH tires or drive our coaches over 100 MPH.
Let's drag in the next dead horse:-)
Tom
2006 Beaver with an air pump driven by a C9 Cat
-----Original Message-----
From: Diesel-RVs@yahoogroups.com [mailto:Diesel-RVs@yahoogroups.com] On
Behalf Of lshields20
Sent: Wednesday, January 02, 2008 6:26 PM
To: Diesel-RVs@yahoogroups.com
Subject: [Diesel-RVs] Re: 07 Toyota/Nitrogen
I'm pretty sure I have my facts straight. I spent wayyyy too much
time in school to mess up the basic stuff too bad. If you are so
certain something I wrote here is wrong, please back it up with
facts, references to textbooks, scientific journals and the like, or
mathematical evidence.
Les
--- In Diesel-RVs@yahoogro <mailto:Diesel-RVs%40yahoogroups.com> ups.com,
"Fred" <havasu01@...> wrote:
>
> Go back to school Les!
>
>
> -----Original Message-----
> From: Diesel-RVs@yahoogro <mailto:Diesel-RVs%40yahoogroups.com> ups.com
[mailto:Diesel-
RVs@yahoogroups. <mailto:RVs%40yahoogroups.com> com] On
> Behalf Of lshields20
> Sent: Wednesday, January 02, 2008 1:46 PM
> To: Diesel-RVs@yahoogro <mailto:Diesel-RVs%40yahoogroups.com> ups.com
> Subject: [Diesel-RVs] Re: 07 Toyota/Nitrogen
>
>
>
> I "think" the air loss through migration is mostly in one's
> imagination. If nitrogen did "migrate" through the tire more slowly
> than oxygen does, what would happen? Some oxygen would migrate
through
> the tire leaving the nitrogen behind. Add plain air to make up and
the
> process repeats. After several such episodes, what do you have left
in
> the tire? It would be nearly pure nitrogen. The process called
gaseous
> diffusion and is one method that can be used to enrich uranium for
> fissile purposes.
>
> Loss through the valve stem is much greater than through the "pores"
> in the rubber.
>
> I must have the best set of Michelins ever made on my 2004 Dutch
Star.
> For the first two years I owned it, I never added air (and I do
check
> them frequently). I have added air about twice since then. Both
times
> were to compensate for me reducing pressure while traveling in the
> south, then adding air to make up during cold months up north.
>
> I highly suspect the transition between summer and winter is the
main
> reason people find they need to add a couple pounds to their tires.
> The ambient temperature change between summer (say 80 degrees) and
> winter (say 20 degrees) is enough to cause a several pound change in
> pressure. At least a pound a month from summer to winter.
>
> I don't believe Costco is run by idiots. I think it is run by very
> good marketing people. If a store can provide a perceived value
> (whether or not it is an actual value) when selling a commodity item
> (a particular tire is pretty much the same no matter where you buy
> it), people are more likely to buy where they get the perceived
value.
>
> Les
>
> >
> > Then why does Costco fill all the tires they sell with nitrogen.
You
> > cannot buy nitrogen from them--it is only something they provide
at no
> > cost for their new tires. I don't believe that Costco is run by
idiots.
> > There must be some value. In my case, the only difference I've
seen
> is a
> > much, much lower of air loss due to migration. But that is a very
> > worthwhile difference for me.
> >
> > Bob Clerc
> > @ Casa Grande, AZ
> >
>
>
>
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