Nitrogen in tires?

[johns4104s]

Is there any advantage to put nitrogen in the toad or coach tires? Better ride? Just what are the advantages?

Thanks

John

[cody]

My understanding of it is the profit is greater for the dealer, the claims made don't seem to add up to any great advantage over just air.

[gus]

John,

The primary advantage is to the guy who sells it. Since air is mostly nitrogen anyway it is just a scam.

You also run the risk, although very slight, of blowing your tire out with the very high pressures in nitrogen tanks.

[luvrbus]

John, I don't know for sure if works or not but Sonja's Lexus has Nitrogen when I bought the tires 5 years Les Schwab did it for free and last week at Costco when she had the tires checked they had only lost 3 to 4 lbs in 5 years.
Fwiw I think it works in the AZ heat as her car sits for months and the tires never bounces (could be the tire) watching Schwab do it they mounted the tire then let the air out and pulled a small vacuum on the tire then the nitrogen but paying 5 or 10 bucks a wheel I would go with the air


good luck

[OneLapper]

Okay, I have to chime in here!

I have used Nitrogen in my race car's tires for years.

Here's my portable set up



Note my Schrader (sp?) valve on the end of the hose!  I used the tank to fill the inside rear tire on my bus after having new tires installed and getting a faulty valve stem.  The shop installed a new one free of charge, but that nitrogen tank filled that tire from 40 to 90 psi numerous times!

On air, I get 10psi rise in tire air pressure on the track in three laps.  With nitrogen, only 4 psi!

I use it in my car trailer tires.  I've never had a blowout since.

The benefits are true.  The cost??? Who knows.  It's all part of the racing budget. LOL!

[OneLapper]

John, I don't know for sure if works or not but Sonja's Lexus has Nitrogen when I bought the tires 5 years Les Schwab did it for free and last week at Costco when she had the tires checked they had only lost 3 to 4 lbs in 5 years.
Fwiw I think it works in the AZ heat as her car sits for months and the tires never bounces (could be the tire) watching Schwab do it they mounted the tire then let the air out and pulled a small vacuum on the tire then the nitrogen but paying 5 or 10 bucks a wheel I would go with the air


good luck

Nitrogen molecules are larger than O2, so they do not leak out of tires as quickly.  Also, there is zero humidity in nitrogen, a huge advantage to tire life. Tires do not like humidity inside them! Steam expands!!!!!

[DaveG]

Also, there is no moisture (basically) in nitrogen so the steel wheel doesn't rust. I don't use it in the big trucks/trailers, but I do on the motorcycles...primarily to limit rust/corrosion on the wheels and they hold air pressure longer.

With the regulator, I don't think that you would over-inflate a tire because the air hose/chuck would probably fail before the tire was aired up. Just my opinion.

Shops that use nitrogen generally use a green valve cap.

[Dreamscape]

Nitrogen has been used for airing up tires for many years, ask the racers. It also doens't expand like oxygen does. I haven't used it, only what friends have said.

Most shops will have it available, they use green caps on the stems to let you know.

[JohnEd]

Tire mfr.s have tables for determining the correct tire pressure by loading.  OK, so duh!  BUT, if nitrogen doesn't have the same ex;pansion characteristics as "air" then you will be off in the "heated under load" end of that equation.

Way back it was common to get a little water out of the compresed air hose.  Now, that never happens today...right?  Water, over time, dry rots tires....I think.  I know that 2 messes with it, for sure.   I think the question is "how much"?  Both in terms of cost and degree.

Scuba air is dry and a little tiny bottle will fill a lot of tires and shoot a gazillion pellets down range.  See, if you are down a hundred feet, well, wet air defeats the purpose.

John....I'm pretty sure

[buswarrior]

From the truck trade press, there are fleets that are running nitrogen, and their tire programs are showing that it works. More consistant pressures, less leakage, good casings. Oxygen is needed for corrosion of both metals and rubber.

Yes, there are lots of dealers using nitrogen as a profit centre, do you blame them?
If folks will pay, that's how capitalism works!

However, for busnut use, with our really low mileage, and that most of us age tires out, the cost/benefit is likely a crap shoot.

Those who are likely to encounter extremes in temp, high and low, might have some benefit to nitrogen use?

happy coaching!
buswarrior

[Sean]

... It also doens't expand like oxygen does. ...

Umm, all gases expand exactly the same way.  The equation is PV=nRT, also called the ideal gas law.

If the absolute temperature goes up 10%, then either the pressure or volume (actually, the product of the two) must also rise 10% -- it doesn't matter whether the gas is nitrogen, oxygen, helium, or even steam.

There are exceptions to this rule at extreme limits, when gases are said to be "non-ideal," but that does not apply to air versus nitrogen in tires.

Note that any liquid component will change the dynamic.  So if you have entrained water in the air supply, then, yes, as the tire heats, the water will vaporize into steam, and that will increase the pressure (or volume) by a greater percentage.  This is one reason why the air supply should be perfectly dry for airing tires.

... On air, I get 10psi rise in tire air pressure on the track in three laps.  With nitrogen, only 4 psi! ...

Then you had water in your air supply.  See above.

Nitrogen molecules are larger than O2, so they do not leak out of tires as quickly.

OK, this part is true -- but just barely.  The difference in size is minute.  Also, if this claimed benefit is really operating at any significant level, then, theoretically, your tires would be mostly full of nitrogen after a few top-ups anyway.  Air is 80% nitrogen to begin with, so after first airing up the tire, it will be 80% nitrogen.  Now let's say that all of the oxygen leaks out, and you find your tire pressure to be 20% low.  You fill the tire back up with air -- now you have 96% nitrogen and 4% oxygen.  If that 4% also leaks out, when you top up again, you'll have 99.2% nitrogen, and only .8% oxygen.  Etc.

Also, there is zero humidity in nitrogen, a huge advantage to tire life. Tires do not like humidity inside them!

Well, OK, but you can also have 0% humidity in "air" too.  Note that nitrogen is made by processing air, not from some other magic process.  That processing removes the  oxygen as well as other trace gasses, and, of course, the moisture.  But it's not perfect -- some trace gasses and even some water vapor remains.  It is certainly easier and less expensive, though, to just remove the water than to remove everything else, too.

Steam expands!!!!!

Uhh, yes, exactly the same way that nitrogen does.  Again, see "ideal gas law" above.  Steam is a gas, which is not to be confused with liquid water.  Liquid water, as I wrote above, can be entrained in the air supply and can vaporize inside the tire, increasing the pressure.  Perhaps this is what you are thinking of.

... Oxygen is needed for corrosion of both metals and rubber. ...

Buswarrior is correct.  This is really the only significant advantage to using nitrogen over (100% dry) air -- oxygen, well, "oxidizes."  Oxidation of the rubber ultimately weakens it.

That said, the likelihood that oxidation on the inside of the tire can have a measurable impact on the life of a heavy-duty tire is very small.  First off, the tire is exposed to oxygen for its entire life up to the point where it is mounted and filled, and so there is already an oxidized layer.  That layer actually inhibits most further oxidation.  As the tire flexes, there will be some additional oxidation.  But most tires will wear out long before this oxidation can become a factor in casing failure.

I personally believe that fleet programs seeing a measurable difference using nitrogen fills are actually reaping the benefits of having a consistent fill source.  By mandating nitrogen fill, you are precluding the driver from filling his tires at some crappy truck island that might be loaded with moisture.

The single largest cause of tire failure is under-inflation.  Take the money you would spend on nitrogen fills and invest in a good tire gauge, and use it before every trip -- you will be ahead of the game.  And you'll compensate for any of those sneaky oxygen molecules that permeated through the casing.

FWIW, JMO, YMMV, etc. etc.

-Sean
http://OurOdyssey.BlogSpot.com

[jackhartjr]

The single best reason to use nitrogen is this.
If you get a nail, screw, etc in a tire that you don't see...and if it is not causing a leak...with nitrogen, you will not get the rust which eventually causes the steel belts to rust, then you get the tire failure.  An old trucker taught me that.
The fleets that use nitrogen are saving big bucks.  Especially if they run in hot climates.  Much less tire failures due to heat.

Sean is right...underinflation kills more tires that anything!

[muddog16]

One lapper, you probably know this, how and where you store your tires.....moisture collects.....on dirt we install reliefs and purge the tire for maybe 10 minutes or longer depending on the humidity, the increase is definately less than what you are seeing........we've used this for about 10 years or longer, with excellant results, chasing the track and tire moisture is the battle!  

[junkman42]

Wonder why the military and the airlines use nitrogen to fill aircraft tires?  Probably just throwing away money!  Regards Johyn L

[rgwilliams]

Fire or explosion safety.  Same reason they use it in the oleos (shocks) in the landing gear.