Got new tires, but no Nitrogen.

Joined
Feb 18, 2012
Messages
890
Location
MA, USA
Humidity makes the air inside the tire to not behave according to universal gas law. If water condenses the pressure drops significantly, if water changes into vapour it raises exponentially (or more). Liquid takes much less room (volume) than gas of the same substance/element. Krzys PS It is mostly theoretical but in airplane landing the temperature goes from -40C to ground temperature (maybe +40C) - 80C delta, approximately 160F delta in few minutes. That may ruin your day if there was water ice crystals that expand into vapour in sub second during the touch down.
 
Last edited:
Joined
Mar 2, 2004
Messages
3,717
Location
Kentucky
I had Costco mount some tires on my truck and they used N2 to air the tires up, green stem caps and all. The pressure DOES hold more constant than my other tires which are serviced with regular air. I went at least a year without having to add air to them, whereas all my other tires require adjusting at least 3-4 times a year. I check air pressure regularly so the difference was noticeable. Not interested in the science behind it-- that's my observation only, not an argument for or against N2 or saying one is better than the other, or that N2 is some magical gas that defies the laws of physics. Despite having seemingly good luck with it, I wouldn't search a tire place out solely for their use of N2, Costco just happened to be convenient and inexpensive at the time. I'm just fine with regular old air as I will check my tires regularly anyways and it's really not a hassle topping tires up a couple times a year.
 

Ws6

Joined
Mar 7, 2008
Messages
4,981
Location
South Central US
Originally Posted by Mr_Luke
I bought a set of 4 new Nankang NS20s and the guy at the new local tore store told me he doesn't think I need nitrogen in them. I used to run nitrogen. I used to seem to have tires that needed be be topped off with air every 1-2 months and the nitrogen seemed to help seal the tires and lessen my need to top them off so often. These tires have been on for 6 or 7 weeks and I don't think I've lost one pound yet. Thanks to this place I saved $100 on these tires and will spare myself of the $25 for nitrogen. As long as they hold their pressure, I'm fine with dry compressed air.
I've literally never added air to my tires. They go 50K miles, no air added. I check pressure before every major trip. Always fine. The air in them now is 70% nitrogen because I'm from planet earth, and so are they.
 
Joined
Feb 22, 2003
Messages
4,295
Location
Somewhere in the US
Originally Posted by krzyss
Humidity makes the air inside the tire to not behave according to universal gas law. If water condenses the pressure drops significantly, if water changes into vapour it raises exponentially (or more). Liquid takes much less room (volume) than gas of the same substance/element. Krzys PS It is mostly theoretical but in airplane landing the temperature goes from -40C to ground temperature (maybe +40C) - 80C delta, approximately 160F delta in few minutes. That may ruin your day if there was water ice crystals that expand into vapour in sub second during the touch down.
Ah ….. Mmmmm …… Not exactly. Ya' see, water vapor DOES behave according to the ideal gas law - so long as it is not close to the dew point (100% humidity). That's the condition most tires find themselves in. It's only where you have HUGE temperature swings where it becomes a problem. Except it really isn't a problem, unless you are racing. It's only in racing where the spring rate of a tire is affected by inflation pressure - and that affects lap times. And unless there is liquid water in the tire to begin with, the pressure buildup would be the same as 0% humidity air. Also, when you take air from an air compressor, water condenses out. Put a different way, the humidity of air in a 100 psi compressor tank is 100% - BUT when you fill a tire to 30 psi, the humidity is LESS. So why do aircraft and racing car use nitrogen? Because it comes in a tank at 1500 psi. Aircraft tires can be inflated to over 300 psi (depends on the tire!), so the easy way to get that kind of pressure is to have a cart with several nitrogen bottles, rather than an air compressor. And it is easier for a race team to transport a nitrogen bottle than all the stuff needed for an air compressor (Don't forget the fuel if the compressor is powered by an IC engine). Take a look at a Formula 1 pit set up. The air guns are powered by nitrogen bottles.
 
Joined
Jun 4, 2013
Messages
1,615
Location
iowa
Here is a decent article on water in compressed air. I know of one car dealers shop whose air compressor quit working from water. Turns out the 80 gallon tank had filled to the top with water, since nobody bothered to drain it daily. The best time do drain a compressor is when it's cool before you fire it up. https://www.vmacair.com/blog/water-compressed-air/
 
Joined
Jun 9, 2012
Messages
1,018
Location
Reno, NV
Originally Posted by Pew
Originally Posted by Mr_Luke
Why is it here that seasoned members like you insult others?
Some* like to talk down on others and act as if they're always right. But like others have said, if you don't have a vacuum to pull out everything in the tire first, the Nitrogen won't help. It's the moisture that expands/contracts with temperature (although O2 does too, just not as much.)
Again, Ideal Gas Law, Oxygen and Nitrogen expand the same.
 
Joined
Jul 9, 2008
Messages
3,599
Location
British Columbia, Canada
Nitrogen and dry air behave in (almost) exactly the same way. The only differences are (1) the minuscule amount of oxygen that would get consumed in oxidizing the tire or iron in the wheel, and (2) the infinitesimally slower rate of diffusion of nitrogen through the tire. I defy any of you to measure either effect. Otherwise they behave in exactly the same way. They don't call it the Universal Gas Law for nothing. If your tires hold pressure better with Nitrogen, it's because they have a better seal. But water is a different story. If you have water in the tires and your tires are near the freezing temperature, either air (78% nitrogen) or nitrogen will behave funny. So dry air, or nitrogen is what you need. I have no problem with nitrogen, it's just fine. But I won't pay extra for it.
 

Mr_Luke

Thread starter
Joined
Aug 16, 2019
Messages
1,244
How are those cheap 12v air compressors that plug into the AC socket / lighter socket? Do they make dry air? It seems that would depend on the relative humidity / dew point at the time you add air. I'm thinking of getting one of those.
 
Joined
Mar 2, 2013
Messages
10,395
Location
The Midwest
The inner liner of a tire is an expensive component and there are good ones and not so good ones to be had. Most all class 8 tires have good ones and the tires leak off much slower as a result vs a typical car tire.
 
Joined
Feb 22, 2003
Messages
4,295
Location
Somewhere in the US
And just to add more fuel to the fire: Water vapor will leak INTO a tire - as well as out. So using "dry air" doesn't remain that way. See the Law of Partial Pressure of Gases.
 
Joined
Jun 9, 2012
Messages
1,018
Location
Reno, NV
Originally Posted by Mr_Luke
How are those cheap 12v air compressors that plug into the AC socket / lighter socket? Do they make dry air? It seems that would depend on the relative humidity / dew point at the time you add air. I'm thinking of getting one of those.
You are exactly correct. I live in Reno and the humidity is often below 10%. With that minute amount of water in the air there is no problem in the tires. As long as the water in the tire is a gas there is no problem, water vapor expands and contracts just like any other gas. The problem arises when there is liquid water present at any point.
 
Joined
Apr 1, 2019
Messages
561
Location
Ohio
I like the nitrogen thing tbh. When I had a set of tires installed at Costco a few yrs ago it was part of the package and not once have I had to adjust the tire pressure. No nitrogen equals winter and summer adjustment.
 
Joined
Dec 4, 2005
Messages
1,775
Location
Kingston
Originally Posted by D1dad
I like the nitrogen thing tbh. When I had a set of tires installed at Costco a few yrs ago it was part of the package and not once have I had to adjust the tire pressure. No nitrogen equals winter and summer adjustment.
I thought it was a scam when we were selling it in the shop so I proved it with my bicycle tires that always lose air. Nitrogen and air with 78/% or whatever it is lost at the same rate over a couple of months. I've had whole sets of wheels that always held air pressure and others didn't. All with regular air with . 76? Nitrogen.
 
Last edited:
Joined
Apr 3, 2017
Messages
3,081
Location
Ontario, Canada
I have worked for both Acura, and now BMW. Both have service bulletins that using nitrogen in tires offers zero benefit to the customer over dried shop air, and should not be recommended or offered.
 
Joined
Dec 26, 2005
Messages
23,730
Location
Upper Midwest
Originally Posted by D1dad
I like the nitrogen thing tbh. When I had a set of tires installed at Costco a few yrs ago it was part of the package and not once have I had to adjust the tire pressure. No nitrogen equals winter and summer adjustment.
That's not due to the gas in the tire.
 
Joined
Dec 4, 2005
Messages
1,775
Location
Kingston
Originally Posted by mightymousetech
I have worked for both Acura, and now BMW. Both have service bulletins that using nitrogen in tires offers zero benefit to the customer over dried shop air, and should not be recommended or offered.
Gm had the same tsb when I worked there. So I already was sceptical when my bosses were trying to push it at independent garages. That's why I tested it on my bicycle and found zero improvement.
 

JHZR2

Staff member
Joined
Dec 14, 2002
Messages
49,511
Location
New Jersey
I take the N2 from Costco when there. Why not? Dry, oil free air is more critical. But N2 is a nice touch. Nothing more, nothing less. Doesn't hurt, but proper dry air doesn't hinder.
 
Joined
Jul 21, 2013
Messages
920
Location
D/FW Metroplex
Originally Posted by Mr_Luke
Originally Posted by splinter
Yeah those sexy green caps notify other motoring enthusiasts that guy didn't do too well in chemistry courses.
I never even took chemistry and I wouldn't need to take chemistry to notice the benefits I got when I ran nitrogen in my tires. The tires lasted me 10 years and about 40,000 miles. I'd say I did well with them. You don't need a weatherman to know which way the wind blows.
Hold the phone...40K miles in 10 yrs?? Was the car broke down? I'm putting 40K miles on my car in 10 months, literally, not figuratively, and no I don't have the same set of tires when I end the 40K as I had when I started it. Maybe I should get some nitrogen to see if that would help...
 
Top