Filling Tires with Nitrogen

[Captain X]

While reading the recent flyers, there was one for a local Auto Shop stating how it's safer and more economical to fill your car tires with Nitrogen. I've not heard of this before, but after doing some Google research, it seems it's a practice being done by professionals for a long time. Can anyone provide some experiences about this and if it is in fact worth it.

Thanks!

[kmltick]

I haven't had it done on any of my cars yet, but I do know that Costco does this. Well they advertise it atleast... so it's worth a bit to check it out. I definitely wouldn't mind trying it out.

[robattoronto]

I fill mine with Helium. Car becomes lighter, saves gas. :lol:

[Shifty]

This has become popular with the fart-can car kids, but it's a complete scam, just meant to part fools and their money. It's true that professional races cars use this technique, but it's impossible that a street car would ever benefit from such a thing, the tires just don't even get hot enough.

An auto writer in the Toronto Star wrote an article about this a while back, but it's dropped off their website, apparently.

[Rehan]

An auto writer in the Toronto Star wrote an article about this a while back, but it's dropped off their website, apparently. http://www.thestar.com/NASApp/cs/ContentServer?pagename=thestar/Layout/Article_Type1&c=Article&cid=1126778827759&call_pageid=1026296450641&col=1026296450133

[eelfliw]

It's worth noting that the air we breath is already 78% Nitrogen. So, pumping pure Nitrogen into your tires only gets rid of that 21% Oxygen and small % other gases. How much benefit it'll have on your street car is highly debatable.

If you really want to have fun, pump Hydrogen into your tires. :cheesygri

[Shifty]

Thanks for that, Rehan! I was looking in the wrong area, obviously.

[bionicbadger]

While reading the recent flyers, there was one for a local Auto Shop stating how it's safer and more economical to fill your car tires with Nitrogen. I've not heard of this before, but after doing some Google research, it seems it's a practice being done by professionals for a long time. Can anyone provide some experiences about this and if it is in fact worth it.

Thanks!

How is it more economical? I can fill up with air for free. Do they pay you to fill up your tires or something?

And I fail to see how its any safer. Is air dangerous?

[Ride-On]

Complete waste of time.

You'd be far better off keeping a closer eye on your tire pressures than by inflating your tires with nitrogen.

[radeonboy]

It's worth noting that the air we breath is already 78% Nitrogen. So, pumping pure Nitrogen into your tires only gets rid of that 21% Oxygen and small % other gases. How much benefit it'll have on your street car is highly debatable.

If you really want to have fun, pump Hydrogen into your tires. :cheesygri

what would happen with helium? really im serious. would it actually float?

[baymoe]

what would happen with helium? really im serious. would it actually float?

Nope, you'd fly! :lol:

[radeonboy]

Nope, you'd fly! :lol:


sorry I did really mean fly. helium rises. >:(

[rc51]

This has become popular with the fart-can car kids, but it's a complete scam, just meant to part fools and their money. It's true that professional races cars use this technique, but it's impossible that a street car would ever benefit from such a thing, the tires just don't even get hot enough.

An auto writer in the Toronto Star wrote an article about this a while back, but it's dropped off their website, apparently.


I wouldn't say it's a complete scam...Costco uses nitrogen when you get tires there, there's no extra charge so how can this be a scam?

Nitrogen isn't affected by outside air temperature as much as normal compressed air..also, nitrogen should be cleaner, ie less moisture, as most places have their own compressors which always will induce moisture, nitrogen usually has to be trucked in = higher controls.

I would recommend nitrogen not for the 'heat' but for the extreme cold temps in the winter so you don't lose pressure during cold spells.

[deep]

Nitrogen isn't affected by outside air temperature as much as normal compressed air..also, nitrogen should be cleaner, ie less moisture, as most places have their own compressors which always will induce moisture, nitrogen usually has to be trucked in = higher controls.

I would recommend nitrogen not for the 'heat' but for the extreme cold temps in the winter so you don't lose pressure during cold spells.

The "moisture in your tires" comment is certainly valid, but pure N2 isn't less affected by temperature than our 78% N2 air (except under extreme conditions never experienced by your tires) so the whole pressure argument is bogus.

If it's free, fine....just don't think anyone is doing you any great favours by using N2 as opposed to "mostly-N2".

[gordholio]

While reading the recent flyers, there was one for a local Auto Shop stating how it's safer and more economical to fill your car tires with Nitrogen. I've not heard of this before, but after doing some Google research, it seems it's a practice being done by professionals for a long time. Can anyone provide some experiences about this and if it is in fact worth it.

Thanks!
Just fill it with air. What if one of your tires need air, are you going to run around and look for some garage that pumps nitrogen?

[rc51]

The "moisture in your tires" comment is certainly valid, but pure N2 isn't less affected by temperature than our 78% N2 air (except under extreme conditions never experienced by your tires) so the whole pressure argument is bogus.

If it's free, fine....just don't think anyone is doing you any great favours by using N2 as opposed to "mostly-N2".

Interesting...all the aviation training I've had, military and civilian for almost 13 years all had in their manuals and text that Nitrogen is more stable under temp. fluctuations. I guess, I should write Pratt & Whitney, Boeing, Lockheed, and let them know that their texts are 'bogus'.

Also you're comparing our natural environment of the 78%, 21% atmosphere to compressed air. Compressed air is not the same as what we breathe in. There's fricken oil in compressed air, I would certainly doubt that compressed air is the same 78/21/x ratio.


2 reasons why they use strictly Nitrogen in all aircraft wheel assemblies.

1 - Temperature stability
2 - Removing oxygen as the explosive component (its a real bummer when your wheel explodes on landing). I have seen the remnants of this happening.

[CompWizrd]

moisture, nitrogen usually has to be trucked in = higher controls.

Actually, they use a special machine to filter out the oxygen from regular air. I forget exactly how many tires an hour it can do

Also, oxygen reacts with the rubber in the tire, whereas the nitrogen doesn't as much, which means your tires aren't being attacked from within by oxygen under pressure.

Sure, the outside of the tire is still being attacked/reacted with, but you gradually scrub off that outer layer as you drive.

[deep]

I guess, I should write Pratt & Whitney, Boeing, Lockheed, and let them know that their texts are 'bogus'.

If they say that N2 is more stable than N2-O2 at the pressures we're talking about, then sure....go for it. 10 years of chemistry tells me that whatever aviation textbooks say, they don't get to change fundamentals of science. This guy puts it nicely:

From http://www.eng-tips.com/viewthread.cfm?qid=120996&page=1

1. Air is 78% nitrogen, N2, and 21% oxygen, O2. So even if you put air in the tire, it's already 78% nitrogen. Many of the so called nitrogen generators don't produce much more than 90% nitrogen.

2. At relatively low pressures (ie tire pressures) N2, O2 and water vapor will all behave as ideal gases, and follow PV=nRT. Pressure will increase or decrease to the same extent as the temperature increases or decreases regardless of which gas is in the tire. (Even at 300 psi, which is about 20 atm, there is little deviation from ideality.) Therefore the comments about N2 not changing in pressure as the temperature changes are without merit.

3. The rate of effusion (or diffusion) of a gas through a porous membrane depends on the molar mass and to some degree on the molecular diameter. N2 and O2 are almost the same size and N2 is lighter than O2 (28 g/mol vs 32 g/mol) so if either gas were to effuse out of the tire, nitrogen would do it more quickly. Luckily, tires are designed not to be porous membranes.

4. N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit.

5. The ozone, O3, in the atmosphere, which is a ground level pollutant, will do a great deal more damage to your tires than the O2 inside the tire. For instance, don't leave a condom out in the air in Los Angeles for a few days. It will develop lots of tiny holes and weaken.

spdracer22 says that dry air is preferably to air with a lot of water vapor. As a tire heats up, the very small amount of H2O present will be in the vapor state which may contribute to the overall pressure very slightly.

Several have suggested that N2 in a high pressure tank is more portable and requires no electricity. That would make sense, particularly for aircraft tires.

I find no reason to believe that N2 is going to produce a "better ride" or "better handling".

The bottom line is that for general passenger car tires or truck tires there is nothing to be gained (other than portability) by using nitrogen rather than air. The biggest gain will be $$$ by the companies that sell nitrogen handling equipment and the tire merchants that appeal to ignorant customers. And who is the biggest loser? Yep, the consumer.

[Webhead]

Just fill it with air. What if one of your tires need air, are you going to run around and look for some garage that pumps nitrogen?

I've bought tires from Costco and they say IF you need to top up just put in regular air for the time being. The next time you're at Costco they'll empty the tire and refill your tire with Nitrogen, no charge.