Is Nitrogen better than air?

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BigFoot48
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Re: Is Nitrogen better than air?

Post by BigFoot48 »

NHRATA01 wrote:
MOBY DICK wrote:Interesting tidbit - as the US was for many years the world's supplier of helium, during the 30s they banned the export to Nazi Germany, which lead them to using Hydrogen instead.
Oh the humanity!
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LH
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Re: Is Nitrogen better than air?

Post by LH »

livesoft wrote:As a scientist who uses liquid nitrogen practically daily, my answer is No. Your tire pressure will not be more "constant" either. PV = nRT. Remember that? It doesn't matter whether you have air, oxygen, argon, helium, xenon, or nitrogen: the pressure change is the EXACT same for a given temperature change. So the first paragraph of the article is myth.
"Myth" is a high standard.



http://www.popularmechanics.com/cars/ho ... ns/4302788
Q: Is there any advantage to using nitrogen instead of compressed air in tires? Will I notice improved fuel economy or a smoother ride? Will my tires last longer?

A: Sort of. From the top: Air is 78 percent nitrogen, just under 21 percent oxygen, and the rest is water vapor, CO2 and small concentrations of noble gases such as neon and argon. We can ignore the other gases.

There are several compelling reasons to use pure nitrogen in tires.

First is that nitrogen is less likely to migrate through tire rubber than is oxygen, which means that your tire pressures will remain more stable over the long term.
The equation does not address the point that the article makes in stating the tire pressure will remain more stable due to slower N2 migration through the tire under pressure differential versus one supposes the O2 migration. There is no evidence provided that it is a "myth". PV = nRT does not address the point made. Right?
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Random Musings
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Re: Is Nitrogen better than air?

Post by Random Musings »

MOBY DICK wrote: 3. Nitrogen is probably quite useful to Bogleheads as keepers of vehicles far longer than most as it eliminates the corrosion at the bead which is the source of most slow leaking tires! The moisture in old air compressors causes this corrosion.
Since I get N2 free via Costco, if this point is valid (and the tires you buy from them don't have this moisture issue to start), I think N2 would then make sense in the cases where cost to consumer is the same as air.

RM
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Re: Is Nitrogen better than air?

Post by SurfCityBill »

SSSS wrote:I use a special proprietary blend:

78% Nitrogen
21% Oxygen
1% Argon

And tiny amounts of Carbon Dioxide & some other secret ingredients.

It's very expensive to buy & mix all the ingredients, but it's totally worth it.

I see we're now analyzing AA for tire inflating ingredients. Perhaps Mr. Bogle has a recommendation?
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Re: Is Nitrogen better than air?

Post by Gill »

I was happy to find this old thread. I just bought a new Lexus and was told there is nitrogen in the tires. I think that's the last time they're filled with nitrogen. Even if it's free, it still is a nuisance and costs money to drive to the free nitrogen. I've always used a pressure tank in my garage to top off tires and will continue to do so.
Gill
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YttriumNitrate
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Re: Is Nitrogen better than air?

Post by YttriumNitrate »

Nitrogen in your tires is soooo last decade. Truly discerning automobile enthusiasts only use Perri-air in their tires.
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Dan999
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Re: Is Nitrogen better than air?

Post by Dan999 »

I bought a car new that had nitrogen in the tires. In the 6 years I have never had to add air. With all my previous cars, I had to add air especially during the winter.
The dealer checks it once a year at inspection time.
I am sold on it.
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MarkBarb
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Re: Is Nitrogen better than air?

Post by MarkBarb »

Regular air is safer. If are chased off of the road and into the water, you can use the air in the tires to breath while waiting for the bad guys to go away. If you have nitrogen in your tires, you're toast. Be safe.
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Re: Is Nitrogen better than air?

Post by Jack FFR1846 »

Air is 78% nitrogen.

Nitrogen by itself doesn't help in tires. In racing at a high level (meaning that you have sponsors paying the bills and that getting 10 feet in a 20 lap race is well worth $10k), it can make a difference.

I attended a seminar at the track between sessions given by a track prep company. They explained that for nitrogen fill, they first will remove all tires from the wheels, thoroughly clean inside and out and leave them all in a room that is highly dehumidified. They are left overnight and then tires are mounted in this room "dry"....meaning no lube, no water, no anything. They are then filled with nitrogen and left overnight. They are then purged of nitrogen and again filled with nitrogen.

This will make a difference because there is virtually no water vapor inside the tires. Water vapor expands more than dry air and more than nitrogen.

This company will also provide trackside assistance including pyrometer testing of tires between laps. You go out and run a good 20 laps with at least a couple hot laps....pull into the hot pits....get the team to pyrometer your tires (3 readings across the tire) and you go out again. If adjustments are to be made, they signal and you come in again....they adjust. You typically repeat this many, many times all day long. The result is that you have a good baseline for tire pressures.

For street cars.......don't make me laugh. People even argue with me about buying winter tires.......properly using nitrogen? Come on.
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clcarter
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Re: Is Nitrogen better than air?

Post by clcarter »

As part of the "Adds" a new car dealer tried to get me to buy lifetime nitrogen for $299. He did not seem to understand PV=nRT.
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Re: Is Nitrogen better than air?

Post by RustyShackleford »

dickenjb wrote:For breathing, air is definitely better.
Absolutely. And though many may think it a silly observation in this thread, imagine you're in the same situation as Sidney Bristow in Season 1 Episode 17 of Alias.
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TxAg
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Re: Is Nitrogen better than air?

Post by TxAg »

I dated a girl about 8 yrs ago who showed up at my place with new blue valve stem caps on her Jeep Cherokee. I asked her what was up, and she said she had it serviced and paid an extra $100 for Nitrogen in the tires.

I told her (nicely) that it was a waste of money. She looked at me like I was an idiot. We didn't work out, hahaha.
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Re: Is Nitrogen better than air?

Post by bottlecap »

CaliJim wrote:Janet!!!!

wiki: "SF6 is the most potent greenhouse gas that it has evaluated, with a global warming potential of 22,800[11] times that of CO2 when compared over a 100-year period."
That settles it. I'm using SF6 at leas until I cancel out winters in my area.

As to nitrogen or air, I don't lose any sleep about it.

JT
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David Jay
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Re: Is Nitrogen better than air?

Post by David Jay »

bottlecap wrote:That settles it. I'm using SF6 at least until I cancel out winters in my area.
And you're in Tennessee. Think much SF6 us northerners would have to use...
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fishboat
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Re: Is Nitrogen better than air?

Post by fishboat »

Having retired from working in chemical-product development, two thoughts come to mind:

1) "Chemodribble" (a term I coined myself actually, def:) Using chemical related terms to sell product that, in fact, mean nothing..but works well as most folks hear the dribble, are suitably impressed that it simply must be true, and pull out their wallet to join the club of discerning consumers. It comes as no surprise that chemodribble runs rampant in the patent literature.

2) ASWCS, ....pronounce it as you will. It's an acronym that stands for Any Stuff We Can Sell. It's the product of unattainable product development budgets..or lazy thinking, most often, both. H.L Mencken had a quote that covers this that starts with, "Nobody ever went..." H.L. had a lot of good quotes.

Even if it's free, there's a loss to us all as someone is using good energy to isolate N2 from air...only to be pumped back into the air, eventually, with a CO2 by-product.

N2 for car tires joins the ranks of copper-laced spandex, LED flashing-light arcs for your ankles, nutritional supplements...endless list.
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Re: Is Nitrogen better than air?

Post by Luke Duke »

livesoft wrote:Your tire pressure will not be more "constant" either. PV = nRT. Remember that? It doesn't matter whether you have air, oxygen, argon, helium, xenon, or nitrogen: the pressure change is the EXACT same for a given temperature change. So the first paragraph of the article is myth.
The "more constant" pressure is due to the lack of moisture (H2O) in the nitrogen, rather than the lack of oxygen. Is it enough to matter? I don't know.
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Re: Is Nitrogen better than air?

Post by SimonJester »

SSSS wrote:I use a special proprietary blend:

78% Nitrogen
21% Oxygen
1% Argon

And tiny amounts of Carbon Dioxide & some other secret ingredients.

It's very expensive to buy & mix all the ingredients, but it's totally worth it.

This is the formula I use in all my tires as well.

I bought a special machine for extraction, storage, and delivery. It comes in handy for clearing dust and debris from my computer as well.
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ram
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Re: Is Nitrogen better than air?

Post by ram »

Is nitrogen better than air:
- Certainly not for breathing. :D
- And marginally if at all for tire inflation.
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investingdad
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Re: Is Nitrogen better than air?

Post by investingdad »

The benefit isn't nitrogen itself.

The benefit is that the nitrogen is dry, a consequence of how it's produced inside of air separation plants.

And I would argue that the very small pressure fluctuations from moisture in your tires is negligible. Airplane tires...different matter.

I could post the calculations that show the volume effects of the condensing and evaporating water in the tire but I'm not motivated to do so.

And so says this chemical engineer...
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Re: Is Nitrogen better than air?

Post by investingdad »

NHRATA01 wrote:
MOBY DICK wrote:1. The HELIUM shortage is real. Helium comes from the reaction at the earth's core that turns hydrogen into helium. It surfaces in Methane ( aka natural gas) streams. The extremely mild winter and discovery of methane in old coal beds (fracking) has necessitated LESS pumping of the streams that contained the helium... thus the shortage.
Due to my job, I am knee deep in the helium shortage issue. Actually every industrial user is pretty much on a 50% supply allocation which is making my life rather difficult at the moment as we are a major user.

The main issue is that by order of Congress, the Bureau of Land Management was ordered to sell off the government stocks of helium to private industry by 2015. So the BLM has been doing this for several years now, and as a result is selling at below market prices. The other issue is the BLM sources have basically "peaked" and production from them is rapidly decreasing. There are new wells coming online, but they are in, how shall we say, more challenging areas of the globe for natural resources - Russia, Qatar, North Africa, China. Now due to my point on the former issue, because market prices were so low, it was not cost-competitive for the energy companies to segregate the helium recovered from natural gas wells. The result is that the US supplies are dwindling, and there is not sufficient volume yet abroad to make up the difference. It's going to be a real challenge for uses where no alternatives exist, such as semiconductors, medical use, and laboratory use. It is also the only element that can achieve escape velocity, so basically once it is released into the atmosphere, it migrates into outer space.

Interesting tidbit - as the US was for many years the world's supplier of helium, during the 30s they banned the export to Nazi Germany, which lead them to using Hydrogen instead.
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wrong question

Post by daveatca »

The correct question is: Is a moisture-free gas mixture in my tires worth the extra cost?
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PhysicianOnFIRE
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Re: Is Nitrogen better than air?

Post by PhysicianOnFIRE »

SSSS wrote:I use a special proprietary blend:

78% Nitrogen
21% Oxygen
1% Argon

And tiny amounts of Carbon Dioxide & some other secret ingredients.

It's very expensive to buy & mix all the ingredients, but it's totally worth it.
Breathing your specialty proprietary blend is much more likely to sustain life compared to 100% N2, which I find to be a little suffocating. :)
Johno
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Re: Is Nitrogen better than air?

Post by Johno »

livesoft wrote:As a scientist who uses liquid nitrogen practically daily, my answer is No. Your tire pressure will not be more "constant" either. PV = nRT. Remember that? It doesn't matter whether you have air, oxygen, argon, helium, xenon, or nitrogen: the pressure change is the EXACT same for a given temperature change. So the first paragraph of the article is myth.
The more constant pressure isn't because nitrogen isn't subject to PV=nRT. It's for two different reasons, one of which is inherent to nitrogen, that it permeates through the tire rubber more slowly than oxygen. The other is not actually inherent to nitrogen but practically tends to be true: less probability of liquid water in the tire which would change phase to vapor at high running speed/temp.

Consumer Reports found that if an air (ie 78% nitrogen) filled tire was ignored long enough to naturally lose 3.5psi, a 100% nitrogen filled tire lost 2.2 psi. The water issue has been found even less significant except for extremes. As others mentioned drier gas could also reduce wheel corrosion but a lot of wheels are pretty resistant anyway.

So if nitrogen is free at the margin*, enjoy the small benefit. If a shop or dealer is offering it as a separately priced service, it's unlikely to be worth it.

* eg. if Costco is the best tire deal, they provide it and don't give you the choice of a discount to refuse it.
LuigiLikesPizza
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Re: Is Nitrogen better than air?

Post by LuigiLikesPizza »

i have some neighbors who are convinced that pushing it through brewed coffee makes for better coffee, but I have yet to try that
Last edited by LuigiLikesPizza on Tue Jan 26, 2016 10:01 am, edited 1 time in total.
adamthesmythe
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Re: Is Nitrogen better than air?

Post by adamthesmythe »

> Water vapor expands more than dry air and more than nitrogen.

>The benefit isn't nitrogen itself. The benefit is that the nitrogen is dry, a consequence of how it's produced inside of air separation plants.

(and other quotes)

These represent plausible explanations for why there could be a difference and are consistent with known physics and chemistry. Since water is not a gas at room temperature, if there is a finite amount of water vapor there will be a temperature-dependent equilibrium between water vapor and condensed or adsorbed water. This will not be described by the ideal gas law.

Now that I understand the source of the difference- I can't imagine that it matters very much unless there is liquid water inside the tires. So I am not going to bother.
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Re: Is Nitrogen better than air?

Post by Johno »

adamthesmythe wrote:> Water vapor expands more than dry air and more than nitrogen.

>The benefit isn't nitrogen itself. The benefit is that the nitrogen is dry, a consequence of how it's produced inside of air separation plants.

(and other quotes)

These represent plausible explanations for why there could be a difference and are consistent with known physics and chemistry. Since water is not a gas at room temperature, if there is a finite amount of water vapor there will be a temperature-dependent equilibrium between water vapor and condensed or adsorbed water. This will not be described by the ideal gas law.

Now that I understand the source of the difference- I can't imagine that it matters very much unless there is liquid water inside the tires. So I am not going to bother.
Again the bigger difference is that nitrogen diffuses through tire rubber more slowly than oxygen: a tire with air will eventually have a slightly though noticeably greater drop in pressure if you neglect to check and top up the pressure long enough. That's a relatively small effect, but bigger than the water phase change issue except in extreme cases.
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Re: Is Nitrogen better than air?

Post by BTDT »

Bogleheads are 'different'......... In another life I gave technical seminars that included discussing the use of nitrogen in on-highway tire applications. On average about half the audience came into the seminar convinced of how nitrogen improves mileage, handling, ride, tire-life, world peace, etc..

After reading all the posts in this thread I found only one Boglehead that 'might' pay for nitrogen for his car tires. I kind of feel sorry for the door-to-door salesman that knock's on a Boglehead's door. NOT!
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Re: Is Nitrogen better than air?

Post by R-Man »

High flying airliners fill with Nitrogen to avoid the moisture in air. At high altitudes the water vapor will freeze causing unbalanced tires when landing which could lead to a blowout. Race cars also wish to avoid moisture because at high pressures and high temperature it can damage the inside of the tire also leading to blowouts.

For ma and pa, you are unlikely to achieve either the freezing or the high temperature/pressure situations achieved by airliners or race cars. :D
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livesoft
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Re: Is Nitrogen better than air?

Post by livesoft »

Dan999 wrote:I bought a car new that had nitrogen in the tires. In the 6 years I have never had to add air. With all my previous cars, I had to add air especially during the winter.
The dealer checks it once a year at inspection time.
I am sold on it.
Dan999
:) The dealer must be adding gas to your tires and perhaps not telling you

I have a Lexus that came with so-called nitrogen in the tires. I pump my tires up with a bike pump once in a while. After all, air temp is quite a bit different in the summer and winter.

Plus my car hasn't been back to the dealer since I bought it about 20 months ago, so no chance the dealer could mess with it.
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crit
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Re: Is Nitrogen better than air?

Post by crit »

Nitrogen diffuses through typical rubber approximately 1/3 as fast as oxygen. This is a result of different effective molecular sizes, and permeability coefficients.

Because air is already ~80% nitrogen, air diffuses about 7% faster than nitrogen alone.

YMMV. Checking air pressure regularly is still the most important factor.
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Re: Is Nitrogen better than air?

Post by Dude2 »

It has been said before, but what cannot be stressed enough is the role of dihydrogen monoxide.
c078342
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Re: Is Nitrogen better than air?

Post by c078342 »

I think that almost all the (miniscule) benefits afforded by N2 can be realized by changing the air in your tires every time you change the oil.
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Re: Is Nitrogen better than air?

Post by pierremonfrere »

nisiprius wrote:...Several months later I was thinking "it's been a while," so I checked 'em again. Front tires, exactly 40 psi. Left rear, 30 psi. Right rear, 20 psi.

After some delicate queries at the dealer, they decided there was nothing wrong with the tires and installed four new valves at no charge. They haven't lost a pound since. What they weren't saying is that, I assume, someone damaged the valves during the tire rotation.

Anyway, here's what I'm leading up to. I consider myself a semi-responsible car owner. But obviously I was driving around for months with twenty pounds in my right rear tire. I don't think I was putting my life at risk, but...

... fill 'em up with nitrogen? C'mon, who would I be kidding? If I didn't notice a difference with a tire twenty pounds down, I wouldn't notice if the tires were filled with laughing gas. And I probably wasted more fuel in three months driving with an excessively low tire than I'd save over the rest of my lifetime using nitrogen.

I don't need nitrogen. What I need is to check my tires more often. And, human nature being what it is, anything that gets in the way of that--like having to make time and perhaps make an appointment for a special trip to the tire store with the nitrogen--is a bad thing.

I think the nitrogen thing must be some kind of race driver chic.

You may not notice it in one tire, but I remember a time when I drove 80 miles on the freeway with a psi between 15-20 in all four of my truck tires after I forgot to fill them back up after a day of off-roading. I definitely felt a difference then.

At any rate, I agree, nitrogen is probably worthless.
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Re: Is Nitrogen better than air?

Post by 2 Tasty »

Agree with everyone on the inanity of using nitrogen for car tires. On a related note, how one compresses the air into the tires makes more of a difference to moisture content than the nitrogen/air debate (or so I've read). The theory goes that tankless compressors allow all of the water vapor in the air to enter the tires, whereas compressors with a storage tank eliminate a significant amount of the water during the compression and cooling cycles (hence the need for the purge valve). So moral of the story is if you fill your own tires, you might want to invest in a nice compressor with a tank.
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Re: Is Nitrogen better than air?

Post by neilpilot »

2 Tasty wrote:Agree with everyone on the inanity of using nitrogen for car tires. On a related note, how one compresses the air into the tires makes more of a difference to moisture content than the nitrogen/air debate (or so I've read). The theory goes that tankless compressors allow all of the water vapor in the air to enter the tires, whereas compressors with a storage tank eliminate a significant amount of the water during the compression and cooling cycles (hence the need for the purge valve). So moral of the story is if you fill your own tires, you might want to invest in a nice compressor with a tank.
Correct. Also, if your compressor runs during relatively low humidity days there will be an order of magnitude less water.
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Re: Is Nitrogen better than air?

Post by NHRATA01 »

neilpilot wrote:
2 Tasty wrote:Agree with everyone on the inanity of using nitrogen for car tires. On a related note, how one compresses the air into the tires makes more of a difference to moisture content than the nitrogen/air debate (or so I've read). The theory goes that tankless compressors allow all of the water vapor in the air to enter the tires, whereas compressors with a storage tank eliminate a significant amount of the water during the compression and cooling cycles (hence the need for the purge valve). So moral of the story is if you fill your own tires, you might want to invest in a nice compressor with a tank.
Correct. Also, if your compressor runs during relatively low humidity days there will be an order of magnitude less water.
I'm not sure of that. At a typical pressure of a compressor, 100psi or so, you're well over the saturation pressure of air so any additional water in the uncompressed air is just going to precipitate out as more condensate.
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Re: Is Nitrogen better than air?

Post by petram »

"regular air" is already 78% nitrogen so no
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