nitrogen or air

[Carbon]

Originally Posted By: Astro14

So, where's the advantage?

You are *still* not going to deny the fact that a tire with N2 loses pressure more slowly than with air. It is an advantage. It's not imaginary.

Originally Posted By: Astro14
Look, I don't mind how you spend your money...but you should know what you're getting for it...in this case, not much.
You would seem to not have understood what I wrote. Go back and read what you wrote? Yeah, right. Most of what you wrote is true. I was only objecting to your misstatement.

 

[Shannow]

If you still have to check your tyres, just as frequently due to simple gas expansion laws, then where's the benefit ?

0.1kPa less underinflated is still underinflated.

 

[Astro14]

I have to check N2 filled tires just as often to compensate for seasonal temperature variations. PV=nRT applies equally to N2 and O2...

Yeah, the N2 permeates more slowly, but that slower permeation doesn't really help that much. O2 permeates about 3x faster than N2, but it only makes up 21% of an air fill, so, the permeation rate of pure N2 is 77% that of air...

In layman's terms, if I should check my tires filled with air every month (to replace lost air), then I should check my tires filled with N2 every 5 weeks to replace lost N2...

wooooeee...that's some big difference there....look at all the time I saved, analagous to going from a 3,000 mile OCI to a whopping 3,900 miles...

That's before considering the partial pressure of O2 reaches equilibrium with the O2 partial pressure inside the tire...once that happens, then the N2 filled tire, and the air filled tire will have exactly the same ratio of N2 to O2 (don't forget, permeation works both ways, so O2 is leaking into your N2 filled tire until there is roughly 3 PSI worth of O2 inside the tire).

I eventually end up with the roughly the same gas mix inside the tire, and since I have to have the N2 filled only at the tire store...I actually take more time to fill/adjust my tires to get the same result...and I paid extra for that privilege??

Is that really worth it?

Sure it is...if you're the one selling the Nitrogen machine!!

Hence this recommendation from Tire Rack: "Rather than pay extra for nitrogen, most drivers would be better off buying an accurate tire pressure gauge and checking and adjusting their tire pressures regularly."

 

[Garak]

Originally Posted By: Astro14
I have to check N2 filled tires just as often to compensate for seasonal temperature variations. PV=nRT applies equally to N2 and O2...

Yeah, the N2 permeates more slowly, but that slower permeation doesn't really help that much. O2 permeates about 3x faster than N2, but it only makes up 21% of an air fill, so, the permeation rate of pure N2 is 77% that of air...


Agreed. Seasonal temperature variation, at least up here, is the main cause of having to adjust tire pressure, aside from actual punctures. If someone's got weather stable enough that they notice the inevitable seepage above and beyond temperature variations, good for them; I envy them their weather.

Nitrogen is overkill, and as you've pointed out, of very marginal benefit, and certainly not worth the cost or even the hassle. I'd get a "benefit" from buying new wheels and tires every 5,000 miles, but I doubt it would be worth the hassle or expense, either.

 

[tommygunn]

Originally Posted By: Astro14
Originally Posted By: tommygunn
Nitrogen is great for most people.

And by most people...I mean the kinda people who never check oil/coolant/tire pressure/if their car has gas before a light comes on...


How? You have to check them just as often, you have to fill them up just as often...N2 is not some maintenance-free wonder gas...please read through the whole thread...read the article that was linked.


This is like putting "klingon" down on a Scrabble board as a joke and having someone immediately get offended and tell you that its not a word and doesn't count.

If someone was smart they'd offer helium. "Improves handling of your car due to lower weight."

QED: Nitrogen is a joke. It fixes a problem that isn't there.

 

[Kestas]

For those of you that tout the benefits of dry air, let me point out that tires are mounted with soapy water which stays inside the tire after it's mounted. I wouldn't be surprised if this moist air condensed inside the tire during winter.

You're probably better off deflating/inflating the tires a few times to purge the moist air during a cold, dry January day in Michigan.

 

[CapriRacer]

Originally Posted By: Kestas
For those of you that tout the benefits of dry air, let me point out that tires are mounted with soapy water which stays inside the tire after it's mounted. I wouldn't be surprised if this moist air condensed inside the tire during winter.

You're probably better off deflating/inflating the tires a few times to purge the moist air during a cold, dry January day in Michigan.


Let me remind folks of Dalton's law - the law of partial pressure of gases. It works with water vapor, too. That means that water inside a tire will eventaully equalize to the water vapor (humidity) of the outside air.