Nitrogen - $5 a tire

Been hearing ads for filling tires up with Nitrogen. So I called the
dealer in one of the ads and asked the theory behind this.
Nitrogen gas pressure doesn't vary with temperature resulting in the
correct pressure holding causing better tire wear and better mpg.
Also, the Nitrogen gas is a better seal against the aluminum rims.

Any vibes on this??

 

It's a scam. Air is 78% nitrogen and it's free.

 

This is the new thing at many tire places that are looking to distinguish
themselves from other tire places and win your business. I believe Costco,
for instance, uses Nitrogen.

If I remember my physical science lessons from HS many yeas ago, ordinary
air is already comprised of about 78% Nitrogen. As such, even if you do not
fill with pure Nitrogen, you are still filling with 78% Nitrogen!

I believe that the Nitrogen molecules are larger, so are less likely to leak
through valve stems, rims, etc. This may also make it more immune to
changes in temperature as well.

Bob

 

It's worth about 20 cents a tire.

 

Yes, you have been lied to. All gases very in pressure with temperature.

Matt

 

Absolutely untrue.

Nitrogen behaves exactly like air in terms of pressure/temperature
expansion. Both are ideal gases and behave according to the ideal gas law at
the conditions inside a tire. You probably learned that in high school, and
forgot. Of course, the guy who lied to you probably did too. I'm surprised
they'd be so quick to think up a lie (like the grinch)

On the seal, that's pretty stupid. You probably knew better. I tell you what
seals better than air - water. Put water in your tires and you'll probably
never have a flat. Just kidding, don't do that, except on the tractor.

The advantage of using nitrogen is that it's not oxygen. Oxygen can oxidize
your aluminum wheel, and to some degree the rubber in your tire. It's a slow
process usually, although sometimes aluminum can get screwed up pretty badly
out in the weather. Inside your tire, though, the advantages would be
marginal. To be honest, I have never seen any evidence of oxidation inside a
tire. I don't think it's much of a problem.

 

Your beliefs let you down, Bob. Nitrogen is smaller than oxygen.

 

Just going from what I read, it's the moisture in ambient air that
amplifies the pressure variations due to temperature changes. Processed
nitrogen is inherently dry. If what I have read is true, you can get
the same benefit by putting a good dryer system on an air compressor to
cut down on moisture content and using dry air instead of normal (moist)
air or nitrogen. Someone else mentioned that oxygen in air degrades the
rubber and metals over time. Also moisture would do that, so there
would be benefits in using dry air from that standpiont too.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

That would violate the laws of physics. The correct statement is that
nitrogen does not vary AS MUCH with temperature as air does.

Yes. First, air is mostly nitrogen so the sealing against aluminum rims
claim is bogus. Second, unless you're driving a race car where 1/2 psi
will make a noticeable change in the handling of the car, its just dumb
to spend $5 on air for your tires.

 

What short memory you guys have:

--------------

Subject: Nitrogen tire filling arrives in Calgary (CostCo)
Date: Sat, 02 Oct 2004 09:49:25 -0400
From: MoPar Man <>
Newsgroups: rec.autos.makers.chrysler

Experts say that nitrogen molecules are four times larger than oxygen.
Retailers say tires with nitrogen should stay inflated four times
longer, maintain a consistent tire pressure and increase its life
span.

Nitrogen tire filling is already widely used in Europe. Costco
doesn't charge any extra for the gas, which is included in the price
of the tire and installation.

Nitrogen -- a dry, inert gas used by racing professionals and the U.S.
military to inflate racecar tires and military vehicles, respectively
-- leaks through a tire's rubber walls three times more slowly than
oxygen. As a result, tires filled with high-quality nitrogen delivered
by IR's system stay inflated longer, which allows them to grip the
road better and provide greater control in all weather conditions.

"It's an obvious safety issue," said Ray Evernham, a three-time NASCAR
Nextel Cup champion crew chief, team owner of Evernham Motorsports and
an IR spokesperson. "Simply put, tires filled with nitrogen provide
more stable pressure. That's why IR's Nitrogen Tire Filling System
represents the best solution for drivers and tire-repair centers."

(and part of the same thread)

I wonder if nitrogen-filled tires play any role in preventing leaks on
aluminum rims or reducing rust and pit formation on aluminum rims.

hmmm. I wonder what the "nitrogen experts" would say about that?

------------------------

Also see this:

---------------------------

Subject: Re: Tires get an expiration date (was: Michelin tires
and their problems)
Date: Thu, 16 Jun 2005 00:01:49 -0400
From: MoPar Man <>
Newsgroups: rec.autos.makers.chrysler

An argument that seasonal tires (still mounted to wheels) should be
stored with the air taken out of them (ie deflated) ?

Also an argument that tires be filled with nitrogen? Perhaps some
other gas?

-----------------------------

 

If you are driving a NASCAR vehicle in competition at 200 mph,
I'd strongly suggest nitrogen in your tires. Otherwise, you will
be quite satisfied by checking and adjusting your tire pressure
on a weekly basis.

You shouldn't be concerned about the minor fluctuations in air
pressure caused by the moisture in your tires. It just isn't that
important for the average driver. And the oxygen attacking the
outside of your tires and alloy wheels is a much bigger concern
that the oxygen attacking the inside. Remember: There is a finite
amount of oxygen inside your tires, whereas the outsides of the
tires and wheels have a nearly infinite supply of oxygen (and salt
and water).

 

hmmmm.. so if I fill my tires with helium, I guess it would make my car
lighter so that there would be less wear on the tire treads.. What a
fantastic idea.. thanks
sharkman

 

True, but it's also monatomic and really, really small, so you may
experience some leakage...

I think some really hard core bike racers were trying this maybe 10
years ago. Since I'm not really part of that scene I don't know if it
ever caught on or was just something a couple guys tried to get an edge.

nate

 

The helium molecule is small and very flexible,. Unless your tire/rim are
VERY securely sealed and the tire itself is tight in the extreme, helium
would migrate right through the tire and leak into the atmosphere far
quicker than just straight air.

 

Unless your tire/rim are VERY securely sealed and the tire itself is
tight in the extreme, helium would migrate right through the tire and
leak into the atmosphere

____Reply Separator_____

Causing everyone in the area to talk like Alvin, Theodore and Simon.

 

Yes. PV = nRT.

DAS

For direct contact replace nospam with schmetterling

 

Well then - guess what that means. It means that if you fill a tire
with air, that in a few months, the smaller molecules will have
selectively been filtered out, and the concentration of nitrogen will
greatly increase through "natural slection". Adding some makeup air
over that first few months to make up for the exiting of smaller
molecules will be adding a smaller percentage of overall smaller
molecules, so you will be asymptotically approach 100% nitrogen over the
course of, what, 6 months to a year.

I've got three year old tires on my car - originally filled with air.
They should be about 95+% nitorgen-filled now.

I still think the cause of the instaneous temperature/pressure effects
are the moisture in typical compressed ambient air vs. dry air or dry
(commercial) nitrgogen.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

This is a big bunch of horseshit. Doesen't anyone know math anymore?

Let's see, even assuming that a molecule 4 times larger leaks through
rubber 4 times slower (which is preposterous malarky) since air is 78%
nitrogen, only the 22% oxygen component in air would be leaking out
at 4 times faster.

If you inflate your tire to max inflation pressure - which for most tires
is 35psi - then even if all the oxygen leaked out the pressure drop on
the tire is only going to be 7psi, which will drop the pressure to 28psi
which is still well within the manufacturers recommendations for most
passenger vehicles.

In my vehicles I see about a 2 psi loss every 6 months - do these nitrogen
bozos think I'm going to stop checking tire air pressure except at 2 year
intervals?!?!

This rubbish was debunked back then in this group as well as the
oxygen migrating through the carcass bullcrap..

Ted

 

This is almost as good as the poor sucker who phoned up Click and Clack
to ask if the air in his tires should be changed. Apparently, someone had
told him that the air gets worn out and goes hard over time -- so it
needed periodic replacement!

 

I'd go with standard air so eventually the heavier molecules would be expelled
thru the tire body simply by centrifugal force.

;-)