This seems analogous to VHS vs BETA video tape formats, back a few years. While BETA was technically superior in some ways (so I've heard), the differences weren't that great, and the ubiquity of VHS made it prevail.
...difficult discussion, like the octane arguments. If you try to give some theoretical fine points, lots of folks object to that, feeling that can be misleading, or that it challenges their opinion on the matter.
I would thing it is just the initial cost of the nitrogen concentrator, plus any maintenance costs it could have. A tire shop isn't going to not fill up a customers new tires, so they are already paying labor to fill the tires.
We use nitrogen in our aircraft tires (about 150 psi). The mechanics have the tall tanks they pull around the ramp. So, it works well in the airline industry.
A true nitrogen fill requires multiple purge-fill cycles, forcing extra labor not needed with an air fill.
Nice aircraft tires. Of course once you get into trucks planes and race cars you get into other important advantages for N2 including fire minimization, etc. Not to mention slower leaking and I guess for a airplane tire it could save quite a few pounds of heavier O2. The good news is N2 is one of the biggest darn gas molecules out there. Otherwise the whole idea of pneumatic tires would have sucked. Corrected EDIT: quick calc I get 2.5 lbs weight savings per airplane tire using N2, assuming vol = 20 x R x r2 where D = 4 ft and d = 3 ft from the picture with the Navy guys in it. The other jet looked much bigger tires I bet at least 30-lbs wt savings just on the one 6-tire set with N2 vs. air.
Why is everyone saying "it's not worth the Cost" to use Nitrogen??? Where is NO Added cost to me to use Nitrogen. The Tire Shop promotes and uses Nitrogen in ALL tires at no cost. The advantage is the reduced moisture content in the tire that wears on the tire and wheel and the near zero loss of pressure over time.
I agree N2 is better and desirable, so if it easy to get for you, by all means get it. However the pressure loss is about 33% slower but it still happens. The moisture issue is not very important. Believe Costco uses N2 too.
I have never seen the option for a Nitrogen fill here in the UK, perhaps we are less gullible or perhaps stingy? How do you remove the Oxygen that is already in the tyre before N₂ filling, vacuum it out? If you use air and the Oxygen migrates out of the tyre over time, don't you eventually get left, after a few top-ups, with mostly a Nitrogen fill when finally the internal partial pressure of Oxygen (circa 200mb) inside, equals the partial pressure outside. So, approximately 7% O₂ at 30 PSI. If there is pure Nitrogen inside, Oxygen will migrate into the tyre until the inside/outside partial pressures equalise, again 7%ish.
Good questions- I guess some people in the past have deflated tire and put N2 in there, purge and fill purge and fill. but these days N2 is not too common in the USA either. In most cases, it would be used by your new tire installer who may offer N2 fill-ups as needed. Yes the O2 definitely comes out faster, and the N2 definitely concentrates. But it's a slow process so just letting O2 leak out is not as good as starting with N2. I am not sure if O2 can migrate backwards against the pressure gradient. Have never heard about that happening. But you are correct the O2 does try to reach the same partial pressure on both sides, so that means if you fill with 95% N2 that is good enough. But you have the right idea. O2 leaks about 3 to 4x faster than N2, but there is also 3 to 4x more N2 in air than O2. So if you could fill the tire with 100% O2 and almost any other common gas, you would see the pressure does not hold well. We are lucky N2 is one of the slowest leaking gases, otherwise we'd be filling tires all the time. One place where N2 might make best sense is the little spare tire. I put a special gas in my spare called STAFILL but that stuff is really expensive (good for small - eg, bike tires).
Wondering about the correlation between people that think nitrogen in tires is wrong and people that think the earth is steady on course
There's probably a dozen or more nitrogen threads over the past decade. They all pretty much say the same thing. Nothing wrong with nitrogen per se. It's just that it's kind of more effort than benefit in many folks' opinion. Bless ya - if it's whomsoever's thing. .
I believe it will take many many top-ups, not just a few. The process will take longer than the usable service life of the tire.
Especially takes and landings - heat build up in the tires - n2 helps keep them cooler running. DBCassidy
I use exactly 78.084% Nitrogen in my tires, and it seems to work quite well. Free and readily available, too.
