Article on nitrogen in tires

Here is the scoop on tires filled with nitrogen.
Popular mechanics

I think they are full of it. Sure air could contain some water but when have you ever seen a tire with enough water in it to see it. They get more water in a tire when they lube the edge of the tire when mounting it.

My question would be how do you get all the "air" out so it is just nitrogen in the tire?

By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.

That compressed air we use is 78 percent nitrogen. I don't see how the remaining 22 percent makes much difference.

don't think i'll run right out and get a bucket of nitrogen for my tires, never had an over inflation problem before !!

To my knowledge, this only is important when you're dealing with things like air/oil struts on aircraft, which can get up where it's very cold, and a small amount of moisture could cause real problems.

Seems like I have heard about different gasses having different molecule size, so one might be less apt to leak out through a porous tube than another?

They fill them with nitrogen, then let it all out, then refill, etc. Some do three some do four times. You get 999999% pure.

Splitting hairs. First, they exaggerate the amount of moisture in the air, then accuse it of causing all sorts of bad things.
I have been using regular atmospheric air in my tires for a lifetime with no measurable ill effects. There are a lot of more important things to consider on an automobile than what kind of gases are in the tires.

I used to subscribe to Popular mechanics, but then most of their articles became so far-fetched that they didn't relate to anything that I do, so I don't get it anymore. Just another example of why the paper/magazine industry is declining. I am happy with atmospheric air in my tires, and some SLIME in bicycle tires for the thorns in AZ! I do notice quite a pressure change in my truck from hot too cold, would nitrogen really reduce that problem?

I think you should use helium. It would lift the vehicle a little and decrease tire flexing. So you would have less heat buildup. But,I wouldn't want to use it on wet or snowy roads. Less traction.

Seems to be about the moisture in air. Unless it is a race car who really cares as air works fine. I get these articles Emailed to me by Popular Mechanics . I don't subscribe.

I also believe race cars have special valve stems that bleed off over inflation letting some air out.

(quoted from post at 08:30:47 05/22/18) To my knowledge, this only is important when you're dealing with things like air/oil struts on aircraft, which can get up where it's very cold, and a small amount of moisture could cause real problems.

Seems like I have heard about different gasses having different molecule size, so one might be less apt to leak out through a porous tube than another?

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Yes, we use N2 for aircraft struts. Both for lack of water vapor, and chemical inert properties. O2 will eventually react with the iron in the steel piston to corrode.

N2 is car tires is silly.

We put nitrogen in the tires of aircraft (mostly jet and turboprop) because it is a basically inert gas that doesn?t react under high temperatures. Regular air/oxygen degrades rubber when it?s heated up so it makes sense with repeated high speed landings, nitrogen will prolong the tires life and improve safety. On regular vehicles unless it?s a race car, nitrogen doesn?t seem to be of much benefit.

steve706, just wondering, when nitrogen is put in aircraft tires, is there a provision to remove the air/moisture already in the tire?

I've seen the the automotive tire shops just blow it in on top of what's already there, seems it would defeat the purpose.

One of the main causes of rubber deterioration is ozone. The normal range at ground level is 10-15 parts per billion. It is the main cause of rubber cracking. If the dry nitrogen has no ozone it is better than regular air, but how do you protect the outside of the tire. The size of the nitrogen molecule does slow pressure loss and nitrogen does not change volume as much with temperature change as some other gases.

So ozone plus sunlight deteriorate rubber on the outside. I read over the PM article rather quickly, but ozone was not mentioned. I imagine the longivity of race car tires is too short to worry about ozone. The outside tire coatings usually contain some antioxidant which would slow cracking. Are there any treatments that have an antioxidant for the inside of the tire?

There are tire covers, but I don't know if they slow air movement at the tire surface but good ones stop sunlight deterioration. At the current price of tractor tires I wonder if it would be worth the time and effort to cover rear tires when there are periods of time say greater than a month where a tractor is not being used. I am going to look up any research to see if anyone has done any such study.
I would probably have to look it up on Proxmire's golden fleece awards.

(quoted from post at 10:05:37 05/22/18) One of the main causes of rubber deterioration is ozone. The normal range at ground level is 10-15 parts per billion. It is the main cause of rubber cracking. If the dry nitrogen has no ozone it is better than regular air, but how do you protect the outside of the tire. The size of the nitrogen molecule does slow pressure loss and nitrogen does not change volume as much with temperature change as some other gases.

So ozone plus sunlight deteriorate rubber on the outside. I read over the PM article rather quickly, but ozone was not mentioned. I imagine the longivity of race car tires is too short to worry about ozone. The outside tire coatings usually contain some antioxidant which would slow cracking. Are there any treatments that have an antioxidant for the inside of the tire?

There are tire covers, but I don't know if they slow air movement at the tire surface but good ones stop sunlight deterioration. At the current price of tractor tires I wonder if it would be worth the time and effort to cover rear tires when there are periods of time say greater than a month where a tractor is not being used. I am going to look up any research to see if anyone has done any such study.
I would probably have to look it up on Proxmire's golden fleece awards.

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Had a buddy who was a wheat farmer. Tire deterioration on disks, drills and tractors was an issue. He painted them with latex paint (cheap, UV resistant) every year after use. I don't know if he kept it up or if there was some other detriment.

As far as molecular size, O2 and N2 are practically the same size although Helium is much smaller.

The article is about racing only, and expansion rate only. Nitrogen is a cheap way to get a very dry gas. Probably not so cheap at a tire dealership. A dryer on an air compressor would do the same thing.

Right on Russ ....... especially when you consider there is already some "room air" inside the tire (between the rim and the tire) before they inflate with pure nitrogen. So you're not getting the "full meal deal" from their nitrogen tank. Just another one of life's mysteries to discuss.

On tubed tires it?s simple because the tubes come vacuum sealed so it?s just a matter of install and inflate. On regular tubeless tires, once you have them mounted you needed to perform an air purge using nitrogen where you fill and drain it down to zero to two psi usually a few times. It is basically impossible to get a tire completely air/oxygen free and the industry standard is 94-97% minimum nitrogen content.

(quoted from post at 10:19:20 05/22/18) Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.

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s that figure before or after it's gone thru the compressor?

Not that it will change anyone's mind but doing a little research on gasses and temperatures might help. If you don't mind checking your air pressure at least once a month you don't need nitrogen. If you're lazy like me and want the pressure to stay the same no matter what the temperature is you might want to use nitrogen. IF you could actually get dry air there wouldn't be near as much benefit. I have never seen a dryer at a tire shop so that argument doesn't work. JMO

Popular Mechanics will not let me read their articles because I use an Ad Blocker, I just figure I am not missing anything.

My BIL used to be a compressed gasses sales supv. He lives in N. Arizona, lots of ups and downs, round and rounds......uses N in his car tires. Says it stays better than plain air....but the real reason is that it's handy. Course he didn't have an air compressor so I bought him one. Haven't heard back one way or the other.

(quoted from post at 12:13:55 05/22/18) I also believe race cars have special valve stems that bleed off over inflation letting some air out.

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Yes they are available and aren't limited to racecars. I've used them and didn't care much for them. Just one more thing to go wrong. I learned in racing that consistency was more important than horsepower. I've used nitrogen for years in my racecars mostly because I could predict the growth of a tire with heat added. An aired tired depending on the source could easily gain 4-10 lbs in just a few laps on a 1/2 mile asphalt oval whereas the same tire would gain consistently 2-3 lbs. I could predict that tire's circumference and consistency. I very rarely completely purged them probably could have had more consistency. Tire temps were 110 to 210 depending on position on the car. I've checked tire temps on my hauler and very rarely exceeded 110 degrees, treaded tires cool much better than racing slicks. I never saw a reason to put nitrogen in my vehicles other than when I had a soft tire on my hauler for the ride home. At such low temperatures they didn't grow that much and regular tires are much stronger to resist the growth.
Race car tires are considered springs and we would adjust the rate by added air or nitrogen to change that, as well manipulated their growth. I have also used air to quick grow a tire sometimes when I couldn't get a tire the exact size I wanted.
The other reason for nitrogen at the race track was that most times it was much easier to cart that bottle and hose hookup than a separate compressor, we also used it for our impacts because you could crank up the pressure and super charge them for quick tire changes. good portable supply for all air tools.
I believe that marketing people used these advantages to get customers to the doors of the tire dealerships. I won't say that it is bad thing to use because it's not but IMHO I don't believe that it is that much of an advantage.
If the focus is on moisture in air then why won't they just invest in air dryers that have been proven to remove most of the moisture. That's what most racers use now as well as air bleeds, which are not allowed in all classes of racecars.
Other methods have come to pass such as vacuuming a tire which I understand to be quite dangerous and has been banned by Nascar and others

(quoted from post at 08:02:20 05/22/18) Here is the scoop on tires filled with nitrogen.
Popular mechanics

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For the a average driver, its snake oil.
Oxygen escapes from the interstices between the molecules on a regular basis, up to 1 psi per month roughly. Nitrogen does not, or it escapes in a much smaller amount because the nitrogen molecules are larger.

In effect over time, the concentration of nitrogen in a tire increases due to this simply by keeping the tires filled.

I use the special 78% nitrogen blend :lol: