Nitrogen Gas

I was flipping through the channels this morning and happen to run across an episode of Trucks or one of them shows on Spike and they were talking about Nitrogen Gas. Specifically they were talking about using it in tire, as the molecules are bigger the O2 and a few other reasons that I forgot.
Has anyone used this vice air/O2?

azwiley1 wrote:
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Costco uses nitrogen as does many tire shops here. I believe pure nitrogen does not expand and contract as much as air resulting in more stable tire pressure with temperature changes. Many people fail to check their tires as seasons change resulting in poor tire wear.

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Costco does huh? I will have to look into it.

azwiley1 wrote:
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At least here in Phoenix. They put a green stem cap on when they use nitrogen.

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The "funny" part of this is that "air" is about 78% nitrogen. Nitrogen is a bit more stable than air with tempature increase but the biggest plus of nitrogen is that it cannot hold humidity. ALso on the leak theory, only the oxygen molecules would leak out if you went with that and that would still leave 80% of the "air" volume. When I was around F4 many years ago they used to use nitrogen in their main tires foe to reasons, one was it was a little more stable and the other is that it did not support combustion because when they got hot brake on F4 they would tow they over pucture strips to "blow" the tire before heat did and the was no burst of oxygen when it burst to fan a fire if one starts. In a car it is like more than a novelty ----------------- TheSnoMan.com

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It's been around for several years now..AZ.
Haven't used it myself, have worked on vehicles with it in the tires.
My personal thunk's on the matter..??
A fine idea. Does what it says. but...... If folks would ck their tire pressures regularly..... this would be one LESS gimmick to charge them for.
mmmmm.....kinda akin to tranny flush'n in my book.
~~ 00 L O
m/o
~:~ marsh ~sips his crownroyal......hooks up the flusher~ ~:~

wrote:
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================== It's been around for several years now..AZ.
Haven't used it myself, have worked on vehicles with it in the tires.
My personal thunk's on the matter..??
A fine idea. Does what it says. but...... If folks would ck their tire pressures regularly..... this would be one LESS gimmick to charge them for.
mmmmm.....kinda akin to tranny flush'n in my book.
~~ 00 L O
I would think that in AZ with as hot as it gets that it would be of a benefit, even when one does check air pressure regularly.

azwiley1 wrote:
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Probably so. I have a tire PSI monitor system on my Caliber. I notice it will read 32PSI in the morning when cold and 40PSI after driving an hour on hot roads.
However, it could be that the sensors themselves are subject to error caused by temperature shifts. Will have to get my old fashioned gage out to check.

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If you remember Boyle's Law from physics class, the pressure increases as a function of temperature so the increase in tire pressure while driving is normal. A good rule of thumb is about 1 psi per 8-10 degrees F.
Mike

Mike Simmons wrote:
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True but the sensors could also have a thermal span error. They're cheap and probably not well compensated.

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If they are OEM sensors, they do not have a significant error due to temp increase, they are quite accurate.
Mike

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Well, the ones on the Charger aren't. I've set the pressure a few times with the same guage and can't get all 4 to read the same after moving the car. I've kept it out of the sun, driven it in a straight line, let it sit all day and tried it at night, Backed out of the garage and right back in and there is always one that is off a pound or two. It varies as to which one it will be.
Roy
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Mike Simmons wrote:
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I assume tire PSI sensors are nothing more than miniature force transducers. They use strain gages to measure deflection from force or pressure. If temperature changes then the transducers flexure expands or contracts. The gages don't know the difference and show an error. I'd be interested in seeing just how well they are temperature compensated. If the error is repeatable between different sensors then the error curve could be programmed into the computer.

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Ex - A&P mech here (Boeings and Lears) -
Nitrogen is used to fill transport category aircraft tires (727, 757, etc), but I was told this is for several reasons - it dissipates heat better (imagine if the reversers are out, and 600,000 pounds is on the wheelbrakes), and in the event of a tire fire or wheel well fire, there's no extra oxygen to feed the fire when the thermal fuse plugs pop out. Also, there's no water condensation at altitude when the wheel cold soaks at 35k feet.
Not sure what the advantages would be in an automotive application, and it seems like a pain in the ass to have to hunt for a nitrogen tank when your tires are low.

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I use a mixture that is 78% nitrogen.

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You notice any advantage or disadvantage to it?

On Sun, 22 Apr 2007 18:35:16 -0700, azwiley1 wrote:
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That's the same one I use! Advantages, first, it's cheap, second, very easy to find, third, it keeps the tires from being flat on the bottom.

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Advantage; cheap.
Disadvantage; being plain old air, it doesn't have that feel of exclusivity to it.
Filling passenger car/truck tires with pure nitrogen is nothing more than a profit add on for those selling the service and a new market for the equipment companies pushing the machinery. In the case where a tire store may do it as a no charge, it merely becomes a sales tactic for why the customer should choose to buy their tires instead of going to the competition.
Yeah, there is a bit of science to support using nitrogen in tires but not enough to make it worth the cost or hassle for us mere mortals.

aarcuda69062 wrote:
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I disagree. The average person going into a tire center here would have gone anyways regardless of nitrogen or not. They're looking for the best prices on a given tire.
My guess is there are other reasons that are money motivated. Such as law suits from tire blow outs even though the owner failed to maintain proper PSI. Or perhaps tire manufactures can claim higher mileage and fewer warranty claims as a result of PSI that is more stable.

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The "average" person doesn't know what they want. Yes, they will eventually go to a tire vendor, but they tend to be a bit clueless when it comes to making an intelligent choice.
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True enough, and when the price is the same between store X and store Y, they'll look for something to finalize the decision. Nixon lost to Kennedy because he 'looked' unshaven in a televised debate.
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Neither of which nitrogen will prevent or avoid. Nitrogen still diffuses thru the rubber, it just does it at a slower rate than compressed air.
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I know of no passenger car/light truck tire manufacturer that mandates using nitrogen to fill, in fact, a few have debunked the supposed benefits.