Inflation gas?

NotmyGTR

Everyone here have regular air in their tires? My dealer delivered mine with Nitrogen fill instead of regular. I used this in Japan on the track.......just one more thing to make the overall tire lighter. Not a big difference, but I was wondering what everyone else got when they picked their car up.

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Lyndo

i think they use nitrogen more just for consistant air pressure isn't it? not to do with weight. that and it doesn't oxidize the tires from the inside or somethin, i was told why its better once but kinda forget now, i don't think it had anything to do with weight but who knows i could very well be wrong.

wstar

I don't know enough about the physics and chemistry of this to say anything completely definitive, but I'm inclined by my rudimentary knowledge of the subjects to suspect it's totally not worth the trouble.

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iceman21_23

it can't be the weight... lets say u have 35psi of regular air in ur tires... its 35 pounds per square inch, to have 35 psi of nitrogen you still have 35 pounds per square inch... so its not weight

FlashBazbo

An acquaintance of mine is owner of a chain of tire dealerships. They sell nitrogen fill as a way, allegedly, to obtain more uniform pressures across the range of tire temperatures.

Air is a tad over 78% nitrogen already. The "pure" nitrogen they use to fill tires isn't 100% nitrogen. (He's not sure what percentage it is.)

I have asked him if there is any real benefit. His answer? NOBODY can detect the difference between a tire filled with 78% nitrogen and one filled with 90%+ nitrogen. There are no scientific studies indicating that it produces any performance benefit. The weight difference per tire is easier to calculate than to weigh -- less than the weight of the dust on a clean wheel. He's not entirely sure there's a significant difference between the nitrogen content of air and the nitrogen content of the nitrogen they sell. His view: It's a rip-off. AND HE TELLS HIS CUSTOMERS THIS! They buy anyway.

Why does he sell it? Because people demand it. And his stores would lose credibility with the aftermarket / custom market if he didn't offer it.

FlashBazbo

35 psi is the measure of pressure, not of weight. 35psi air weighs the same as 10 psi air.

jimClark53

That's basically it, Nitrogen is also slightly stiffer than normal air so the ride gets a tad worse, very few notice, but handling unchanged. The increase in density compared to normal air is almost no effect to weight. If you get air from a +120 PSI compressor with a nice tank with an auto water drain, you will be using air that is pretty dry, the water vapour is the culprit for air pressure variation at very high tyre temps, and any internal corosion if the tyres inner liner has any pin holes, but this is rare tyres normally wear out well before has effect anyway. So try not to use the cigarette lighter socket inflator.

lww

Nitrogen use has absolutely nothing to do with any of the factors previously mentioned.

Check out: Tires - Nitrogen air loss study: Consumer Reports Cars Blog

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ricer333

It pretty much comes down to the molecule size of Nitrogen is slightly larger than Air. So the normal leakage of Nitrogen from the inside of the tire to the outside is less than air.

This means that for the normal person that DOES NOT check their tire air pressure on a regular basis, a more consistent and longer tire inflation is achieved.

For many of you that are good about maintaining your cars there doesn't seem to be much difference. At times the Nitrogen argument seems a bit 'gimmicky'. But to each their own. I'll stick with air and just keep up on the maintenance (checking tire air pressure on a regular basis).

Linky

JB1

As far as I know the volume of Nitrogen is affected less by changes in temperature then air is. So with Nitrogen your tire pressure remains (more) stable under changing temperature conditions, whereas the pressure in air filled tires will increase when the temperature goes up. Handy when you drive from Alaska to Arizona or when you take your Z to the track.

ChrisSlicks

The higher the pressure, the more molecules are crammed into the same space, so the higher the weight. But air is so light, at standard pressure is weights only 0.08 pounds per cubic foot, so there wont be a measurable weight difference in the tire. If you had monster truck tires with a volume of 15 gallons, you would add about 1 pound if you pumped them to 100 psi. There will be no significant weight difference with any other gas.

Vs dry air, nitrogen is going to respond to heat at about the same rate as air. As temperature increases, the gas will try to reduce it's density, which when inside a fixed size volume (for arguments sake) will increase its pressure. The water vapor may respond at a different rate, so that may be the only significant difference.

Perhaps there is benefit to aging, but most tires I've seen crack up on the outside first due to the sun cooking the oils out of them.

spearfish25

There are certainly a lot of completely wrong answers in this thread thus far.

Nitrogen is an inert gas and as others have said, 'air' is 78% nitrogen. Removing the oxygen and insignificant other gases from the tire inflation composition won't do much other than minimize oxidation to the surfaces within the tire. As Chris has noted, the weight difference between air and nitrogen alone will be negligible in our tires. Molecular size is also not a factor for tire inflation...tires are not selectively permeable membranes that would leave you with pure nitrogen as the oxygen diffuses out more quickly (very funny idea though). Nitrogen's molecular size is nearly identical to that of oxygen anyway.

The ironic part of all this is that people actually pay more money (or any money, if you will) for a nitrogen fill. In SCUBA diving, we pay a small amount more to minimize the composition's % of nitrogen by adding more oxygen to the fill. This blend is called Nitrox and usually it's only a couple dollars more expensive...and this is a filtered, clean blend that we are actually breathing. Paying more for an abundant gas that gives no benefit and doesn't need to meet any cleanliness guidelines is really not necessary.

TheWeatherman

Agreeing with Spearfish, the scientist above. I actually, mildly poke fun at any friends when they said they paid $10-$20 for a tire fill. I explain what Spearfish said, and they never do it again. There's always someone trying to make money off of you. You better off buying "Acai berries." He he.

jimClark53

You can say that again, try filling with Helium, you will find it does not leak as you would expect, the tyres inner coating is rather Helium proof. So its not leakage. Oh and Helium is softer as a spring medium compared to air.
All you need is dry air.

scorpion90

As a tire engineer for many years with Goodyear, I can tell you that nitrogen inflation has only one plus attribute for tire inflation, and that is it won't migrate through the butyl lining of the tire nearly as fast as standard air does. We have run tests and can confirm significant reduction in inflation loss over time. Basically, you won't have to check your car's inflation monthly as you should, but maybe only ever three to four months. Nitrogen inflation won't do any good if leakage is from the valve stem or valve itself, and those items have been cheapened up over time. Hope this helps.