Nitrogen?

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Mean_Green

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Thinking about getting new paws next spring. What is the typical cost to do all four (five?) with Nitrogen? Can you add normal air later?

Is there a reason NOT to?
 

Eman85

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Do a google for the percentage of nitrogen in the air we breathe. I'd say the only benefit or pure nitrogen is clean and dry air. Spend the money on a good tire pressure gauge and keep them inflated, that kills tires more than "normal" air.
 

Joseph Garcia

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If you like to spend money for no good reason, go ahead and purchase the nitrogen fills. Otherwise, it is a complete waste of money. As indicated above by @Eman85, the air that we breath and what normally fills tires is already 78% nitrogen, and an additional 22% is not going to make any difference whatsoever for non-racing applications (not sure that it would even make a difference there either).

Note that some shops have better drying and filtration equipment than others on their compressed air systems, and it probably makes sense to get as close to clean and dry air as practical.
 

PPV_2018

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“Pure” (read: straight, as not even UHP Nitrogen is 100% pure — there will always be impurities in the gases) Nitrogen is lighter than atmospheric air (which is already over 3/4 nitrogen already), and due to it’s chemical makeup, may keep a tire inflated for longer versus atmospheric air. Despite misinformation, when a tire is filled with “straight” nitrogen, it has less resistance from friction versus atmospheric air. The result is a marginally better and often negligible benefit in gas mileage and perhaps tire life.

Nitrogen is inert, you can add it to air; you can add air to nitrogen, or have any mixture percentage of the two in a tire at any given time. Obviously, you will not receive the marginal benefit of n2 in the tires if it’s being cut with atmospheric air anyways.

I’ve done my own calculations and over a lifetime, a home rig of n2 costs far less than filling up w/ air at gas stations. Actual results may vary depending on more factors that can be listed here. The cost for a home rig is cheap once you get the initial investment out the way.

Here’s mine:

OFZ9O2x.jpg


Bottom line: any reason NOT to do it? No. But if you’re expecting nitrogen to be some sort elixir that will improve gas mileage tenfold, you will be disappointed.
 

wjburken

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Thinking about getting new paws next spring. What is the typical cost to do all four (five?) with Nitrogen? Can you add normal air later?

Is there a reason NOT to?
No mechanical or harmful reason to NOT do it.

You can add air to nitrogen filled tires, just like you can add nitrogen to air filled tires.

That being said, you will never be able to get pure nitrogen in your tire unless you have a way to draw a vacuum and remove all of the air that is trapped in the tire when it is mounted. The trapped air (at atmospheric pressure) amounts to roughly 35% of the total volume (25% of which is not nitrogen) of a tire inflated to 40psi assuming 255/50R20 tires which have a volume of just under 4000in^3. This leaves roughly 9% of the gas in the tire being not nitrogen. That is if my understanding of the Ideal Gas Law is correct, but it is the Saturday after thanksgiving and I’ve only had one cup of coffee.
 

Joseph Garcia

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“Pure” (read: straight, as not even UHP Nitrogen is 100% pure — there will always be impurities in the gases) Nitrogen is lighter than atmospheric air (which is already over 3/4 nitrogen already), and due to it’s chemical makeup, may keep a tire inflated for longer versus atmospheric air. Despite misinformation, when a tire is filled with “straight” nitrogen, it has less resistance from friction versus atmospheric air. The result is a marginally better and often negligible benefit in gas mileage and perhaps tire life.

Nitrogen is inert, you can add it to air; you can add air to nitrogen, or have any mixture percentage of the two in a tire at any given time. Obviously, you will not receive the marginal benefit of n2 in the tires if it’s being cut with atmospheric air anyways.

I’ve done my own calculations and over a lifetime, a home rig of n2 costs far less than filling up w/ air at gas stations. Actual results may vary depending on more factors that can be listed here. The cost for a home rig is cheap once you get the initial investment out the way.

Here’s mine:

View attachment 443791

Bottom line: any reason NOT to do it? No. But if you’re expecting nitrogen to be some sort elixir that will improve gas mileage tenfold, you will be disappointed.
Unless you are purchasing hospital grade compressed nitrogen, it is really not all that 'pure'. I used compressed gas custom mixes of nitrogen and oxygen for years while doing deep decompression wreck diving, and the difference in purity between hospital grade nitrogen and commercial nitrogen (and oxygen) was very significant. I know, we are talking about filling tires, and not a breathing gas here, but I did want to make this point about compressed gas purity standards.

Adding to @wjburken comments above, IMO, the weight difference between 100% nitrogen and compressed air is minimal, since the other major element in compressed air is oxygen, which is only 1 element higher and only 2 atomic units heavier on the Periodic Table, and that difference gets further reduced by the gas composition ratios, which nets you a 3% weight reduction by converting to 100% nitrogen. Yes, 3% is larger that 0%, but I think I'd be hard pressed to notice any significant difference between the two.
 

PPV_2018

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Unless you are purchasing hospital grade compressed nitrogen, it is really not all that 'pure'. I used compressed gas custom mixes of nitrogen and oxygen for years while doing deep decompression wreck diving, and the difference in purity between hospital grade nitrogen and commercial nitrogen (and oxygen) was very significant. I know, we are talking about filling tires, and not a breathing gas here, but I did want to make this point about compressed gas purity standards.

Adding to @wjburken comments above, IMO, the weight difference between 100% nitrogen and compressed air is minimal, since the other major element in compressed air is oxygen, which is only 1 element higher and only 2 atomic units heavier on the Periodic Table, and that difference gets further reduced by the gas composition ratios, which nets you a 3% weight reduction by converting to 100% nitrogen. Yes, 3% is larger that 0%, but I think I'd be hard pressed to notice any significant difference between the two.

Well I agree, and If we’re going to make a point about gas purity standards; then no gas is “pure”, there is no such thing as a “pure” gas, which is why I put “pure” in quotation marks and referred to this “pure” gas that everyone speaks of as “straight”. Maybe you could come close in a scientific laboratory in a tiny volume strictly for experimental purposes, but even then I doubt it, most gas used scientific (read: highest purity, aka UHP*) research and laboratory precision testing usually has the impurities accounted for.

The same can be said for both industrial and medical gas classes. No grade of gas, neither industrial, UHP (ultra high purity*), or medical is 100% pure. Likewise, even medical oxygen and what is dubbed as “breathing air” is NOT 100% pure. Generally, the standard for industrial grade “purity” is >99.9995%, but could be higher or lower depending on the particular batch. Each batch of air separated nitrogen is analyzed and given a COA. Similarly, medical and other UHP standards are, as you suggest, more stringent. The exact percentage can vary, but again generally we’re looking at >99.99990% or higher in that regard. Said all that to say, that no gas is pure. It doesn’t exist, therefore it should be referred to as straight nitrogen.

So while yes, we’re talking about tires, actual industrial nitrogen “purity” is still pretty good, and if we’re taking the advantage vs disadvantage of nitrogen in tires to a scientific level, then roughly 22% difference in nitrogen content in “straight n2” versus atmospheric air *could* make a difference if each tire was filled completely with n2.

One interesting point mentioned above is the atmospheric air residue in the tire which would make it impossible to fill with 100% straight nitrogen. I suppose this could be a factor, but also believe that the tire could be purged out with n2 via the valve stem if the tire was already mounted on the wheel. That I’m not too sure about, but if anything it would reduce the percentage of atmospheric air to a lower amount, even if not 100%.

Of course, I do not disagree that the benefits are, or could be, at best, negligible — which I made a point to emphasize in the post. I suppose the factors and variables in each particular application could provide more or less “benefit” of n2 filled tires. There is a reduction of friction between the tires and road with the lighter gas, and a noticeable difference could rely on many factors, but one possible variable is that much larger tires, such as heavy A/T off road tires or medium and heavy duty truck tires may benefit more from n2 fills than our Tahoe’s.

But one point that I would like to add, for the cost of the fill of that n2 tank, I spend roughly .36 cents for a full tire fill @ 40 psi. If a gas station compressor costs you 1.25, for filling surely less than 40 psi, then over the years there is actually more potential to save money from paying to use gas station compressors, or even buying a portable air pump which I had mentioned in another thread vs. saving money from better gas mileage. Add in the convenience factor of being able to fill any tire, to any psi, in literal seconds is another reason why I have the rig, but hey, to each his own.


If you really want to experiment with better gas mileage, you could try filling your tires with helium… of course, remember to take out an SBA before you go :)
 

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But one point that I would like to add, for the cost of the fill of that n2 tank, I spend roughly .36 cents for a full tire fill @ 40 psi. If a gas station compressor costs you 1.25, for filling surely less than 40 psi, then over the years there is actually more potential to save money from paying to use gas station compressors, or even buying a portable air pump which I had mentioned in another thread vs. saving money from better gas mileage. Add in the convenience factor of being able to fill any tire, to any psi, in literal seconds is another reason why I have the rig, but hey, to each his own.

Just curious about your cost -- .36 cents. Do you mean less than a penny, or $0.36?
 

PPV_2018

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Just curious about your cost -- .36 cents. Do you mean less than a penny, or $0.36?
My fault, initial post had the 0 and I took it out. for clarity:

$0.36 as in 36 cents per tire. That is still less than 1 cent per 1 psi.
 
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Mean_Green

Mean_Green

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The cost for a home rig is cheap once you get the initial investment out the way.
And that is?

I don't drive enough for mileage to be an issue. They sit in the garage 29 days out of each month. But I'm curious about slow leaks and I might even use it in lawnmower tires for the same reason.
 

wjburken

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And that is?

I don't drive enough for mileage to be an issue. They sit in the garage 29 days out of each month. But I'm curious about slow leaks and I might even use it in lawnmower tires for the same reason.
Not sure how nitrogen will help with slow leaks. A nitrogen molecule is .305 nanometers in diameter while an oxygen molecule is .299 nanometers. A human hair is between 60,000 and 100,000 nanometers. Pretty sure if there is a leak point that will let air out, it will let nitrogen out as well.
 

PPV_2018

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And that is?

I don't drive enough for mileage to be an issue. They sit in the garage 29 days out of each month. But I'm curious about slow leaks and I might even use it in lawnmower tires for the same reason.
Cost can vary depending on the brand and quality of equipment. Biggest variable is the tank, which cost significantly less used than brand new (& can usually be found easily on Craigslist or fbmp

But you can do the whole set up for roughly $150 (plus fill) assuming you get a used tank for around 60 bucks. Can buy a regulator for around $40 and the couple feet of rubber hose and the brass sittings required for less than $50. Oh yeah, and you’ve got to take it to get filled, less than $20 locally at welding supply shop.

My set up was around $240, that’s because I sprung for a quality all brass regulator and the quick connect which was not required, just makes it easier. The only true consumable is the hose which is susceptible to dry rot if stored improperly. Everything practically lasts forever if you take care of it.
 

Joseph Garcia

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And that is?

I don't drive enough for mileage to be an issue. They sit in the garage 29 days out of each month. But I'm curious about slow leaks and I might even use it in lawnmower tires for the same reason.
My home compressor setup, which I've had for years, cost me about $350 at Harbor Freight, which included a 4.5 SCFM compressor and 21 gallon tank, 50 ft. of hose in an enclosed, spring-loaded reel, and the tire inflator device with pressure gauge. Of course, tire inflation is only 1 small use case for this equipment, with many other uses across the year.

I will note that I previously purchased 2 different $100 'small' compressors (120V AC, but really a 12V DC motor) with pancake tanks (Husky and Rigid), and they both failed within 1 year. Maybe, it was just me, because I see these small compressors in use in many places.
 

Joseph Garcia

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Well I agree, and If we’re going to make a point about gas purity standards; then no gas is “pure”, there is no such thing as a “pure” gas, which is why I put “pure” in quotation marks and referred to this “pure” gas that everyone speaks of as “straight”. Maybe you could come close in a scientific laboratory in a tiny volume strictly for experimental purposes, but even then I doubt it, most gas used scientific (read: highest purity, aka UHP*) research and laboratory precision testing usually has the impurities accounted for.

The same can be said for both industrial and medical gas classes. No grade of gas, neither industrial, UHP (ultra high purity*), or medical is 100% pure. Likewise, even medical oxygen and what is dubbed as “breathing air” is NOT 100% pure. Generally, the standard for industrial grade “purity” is >99.9995%, but could be higher or lower depending on the particular batch. Each batch of air separated nitrogen is analyzed and given a COA. Similarly, medical and other UHP standards are, as you suggest, more stringent. The exact percentage can vary, but again generally we’re looking at >99.99990% or higher in that regard. Said all that to say, that no gas is pure. It doesn’t exist, therefore it should be referred to as straight nitrogen.

So while yes, we’re talking about tires, actual industrial nitrogen “purity” is still pretty good, and if we’re taking the advantage vs disadvantage of nitrogen in tires to a scientific level, then roughly 22% difference in nitrogen content in “straight n2” versus atmospheric air *could* make a difference if each tire was filled completely with n2.

One interesting point mentioned above is the atmospheric air residue in the tire which would make it impossible to fill with 100% straight nitrogen. I suppose this could be a factor, but also believe that the tire could be purged out with n2 via the valve stem if the tire was already mounted on the wheel. That I’m not too sure about, but if anything it would reduce the percentage of atmospheric air to a lower amount, even if not 100%.

Of course, I do not disagree that the benefits are, or could be, at best, negligible — which I made a point to emphasize in the post. I suppose the factors and variables in each particular application could provide more or less “benefit” of n2 filled tires. There is a reduction of friction between the tires and road with the lighter gas, and a noticeable difference could rely on many factors, but one possible variable is that much larger tires, such as heavy A/T off road tires or medium and heavy duty truck tires may benefit more from n2 fills than our Tahoe’s.

But one point that I would like to add, for the cost of the fill of that n2 tank, I spend roughly .36 cents for a full tire fill @ 40 psi. If a gas station compressor costs you 1.25, for filling surely less than 40 psi, then over the years there is actually more potential to save money from paying to use gas station compressors, or even buying a portable air pump which I had mentioned in another thread vs. saving money from better gas mileage. Add in the convenience factor of being able to fill any tire, to any psi, in literal seconds is another reason why I have the rig, but hey, to each his own.


If you really want to experiment with better gas mileage, you could try filling your tires with helium… of course, remember to take out an SBA before you go :)
This has been a great group discussion, and folks here have the information to make their own choices. This is what this Forum is all about (versus the BS that flows like lava on Facebook and X). This is yet another example of why this Forum ROCKS!

Just for giggles, I've attached a few photos of the 100% O2 and 50%/50% O2/N2 tanks (300 cu. ft.) and gear that I used for my decompression stops during my wreck dives. I also used 100% Argon in my dry suit, since it has 4 times the thermal insulation value as air. This is how I got involved with custom gas mixes.

TT4-1990s 176.jpg


TT4-1990s 253.jpg


TT4-1990 475-brightened.jpg


Side View - Reduced Size.jpg
 

15burban

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But I'm curious about slow leaks and I might even use it in lawnmower tires for the same reason.
Fix a flat or slime works great for slow leaks in atv/lawnmower tires. Going on 7 years since I put it in one tire on our polaris. I've never had to air it up since.
 

homesick

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This has been a great group discussion, and folks here have the information to make their own choices. This is what this Forum is all about (versus the BS that flows like lava on Facebook and X). This is yet another example of why this Forum ROCKS!

Just for giggles, I've attached a few photos of the 100% O2 and 50%/50% O2/N2 tanks (300 cu. ft.) and gear that I used for my decompression stops during my wreck dives. I also used 100% Argon in my dry suit, since it has 4 times the thermal insulation value as air. This is how I got involved with custom gas mixes.

View attachment 443872

View attachment 443873

View attachment 443874

View attachment 443875

Divers do it deeper?

joe
 

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