Nitrogen?

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Get your own pump. A useable bicycle floor pump can cost under $20, and allows you to top off tires at home while they are really morning cold.

For those too lazy to hand pump tires up to 40-ish pounds, just pay at the service station once. Then top off future leakage by hand at home.

12V electric pumps start at a slightly higher price. But with mine, re-stowing the cord into the small compartment is more hassle than grabbing the bicycle pump.

 

OK well it was 38F today in the PA/MD mountains, so I filled up with gaso + air today at the gas station.
The air cost me $1 and the gaso cost me $32. I leave it to the accountants to inform me which fluid refill was the most cost effective.

PS- 12 oz cappuccino was $1.25

 

some guys with model T's ' have been filling their tires with nitrogen for years, i never could see it. you have to get "all" the air out for it to have 100% nitrogen, so your gonna pay to pump it in then let it out a few times. truthfully like low profile tires, nitrogen is used for indy 500 type cars, and it is just the latest fad. hopefully toyota engineers will revert back to the wide side wall tires in the future.

 

Gee . . . . the air is free here but the cappuccino is $4.50

 

That's funny I think we bought coffee at that station too but closer to $2.
You know the O2 comes out 4-5x faster so with time you get mostly N2 in there.
I think if you can get N2 in the new tires (eg COSTCO) and then top off with air that is practical.
But for pros in the race cars sure dry N2 has important benefits of consistency etc.

 

And your top offs are free at Costco and of course Nitro is used with all new tire mounts at Costco. I get a kick out of what some places charge for Nitro fills. PS Costco does not sell coffee here

 

WEll, don't know what to tell you, I have 2 cars in my driveway, 1 with Nitrogen in the tires and the other with regular air, in the winter, the one with Nitrogen doesn't change, the PSI is exactly the same, the one with regular air, loose PSI. at about -20 C, it went from 32 psi to 25 psi. So, maybe most of you don't live in a cold envirenment and if this is the case, then you don't have to worry about it. but for some of us we do, and it for ME, it makes a difference.

Thank you for listening.

 

The problem with your anecdote is you're not comparing like to like. Those are two different cars with 8 completely different tires and wheels. Even if they are the exact same model vehicle with the exact same model tires. They are still not the exact same tire. In order to substantiate your claim that nitrogen is better. You need to put regular air in car 1 and for a second data point nitrogen in car 2. If the reverse happens with Car 2 with PSI unchanged, then you have a more valid claim that nitrogen is superior to regular air.

Otherwise, I can easily say car 2 has an leak in it or was filled with wet air.

 

The problem with your claim is that it is a prima facie violation of the Combined Gas Law. Extraordinary claims require extraordinary evidence, and this has major implications far beyond nitrogen in tires.

As a side note, your claim also contradicts my experience with Costco's free nitrogen fill, and with Consumers Reports' nitrogen tests. But those are small potatoes compared to the Gas Law violation.

 

Nitrogen is snake oil cut and dry. Just like most vitamins, it makes you feel good when you use it/them but the real effect is nothing more than a placebo.

 

Nitrogen and oxygen both behave like ideal gases at normal tire pressures and temperatures, so neither is "less susceptible to temperature." Likewise the diffusion rate of the two is nearly identical; so close that you need laboratory equipment to measure the difference over a year when diffusing through tires. Dry nitrogen has the advantage of not containing water vapor, which is decidedly not an ideal gas at normal tire temperatures and pressures. However, if air is dried this advantage is lost.

The long and the short of it is that nitrogen fill for family automotive tires is just snake oil; pure, unadulterated snake oil. The purveyors of this product make outlandish and unsupportable claims, but the claims seem to work, as many gullible people continue to be taken in. Save your money for fuel line magnets and deer whistles.

Tom

 

Fuzzy, There is a parallel universe where the placebo effect trumps the combined gas laws.

Note to those who subscribe to faith based science: They are called the 'gas laws' instead of the 'gas suggestions' for reason.

 

...diffusion rate for O2 is said to be ~3-4 times N2 thru a tire wall; that is the "theoretical" basis for the N2 hype. But diffusion is not a huge impact, because air is mostly N2 anyways. The implication of this is with the passage of time you have more N2 enrichment in the tire anyways which further minimizes the difference. Costco is not putting dry N2 in new tires for nothing, I think it is nice to start off with N2. But you'll never see me extra paying for it.

 

The earth atmosphere "normal air" is already 78 percent nitrogen. Oxygen "21 percent" is a 3 percent smaller molecule than nitrogen.... "almost the exact same"
Oxygen "oxidizes" the outside of the tire to age it "as well as sun etc" regardless of what's on the inside.

Remember in government and the market place what's reality is not what matters... It's the "perception" of reality is what sells.

In other words, marketing drives many of the gimmicks.
If you can make it look like your doing something different and special. Then others have to follow to compete.... The whole time the ignorant masses are driving the market.

Costco sells what's sells..... When it stops selling, they drop it.... Even if it's as good as mothers milk.....
Someone has to want to drink it and create a demand, otherwise you won't find it in the market.
Nitrogen Filled Tires: a Scam? « Hot Cup of Joe


SCH-I535 ? 2

 

^^^Please Google the science calculations and Consumer Reports tire experiments.
O2 molecule is smaller than N2 (as you state) I am not sure how much smaller.
>>>This leads to 3 to 4 times faster diffusion rate of O2 thru the car tire compared to N2!!!

Sample Calcs:
(a) 100% N2
Let's say 100% N2 leaks at 1 psia per 3 months via diffusion thru tire wall.
100%N2 x 1 psia/3-month leak rate = 1 psia loss

(b) Air 79%N2, 21%O2
How much would air leak in the same 3 months?:
79% N2 x 1 leak rate = 0.79 psi
21% O2 x 4 leak rate = 0.84 psi
so 0.79 + 0.84 = 1.63 psia loss over 3 months for Air vs. 1.0 psia loss over 3 months for N2

This is about what Consumer Reports measured but I did not steal their exact numbers.
This is the basis for the N2 hype but you can certainly argue it is not worth it.

But then moisture (if high) is not good either and can cause greater temperature drop pressure loss.
So Dry N2 is superb, Dry Air is excellent, Water/Air mix is less good for tire refills.

 

The diffusion rate of O2 is nowhere near 3 to 4 times that of N2. O2, in theory, is actually a larger molecule, so theory would predict it to have a marginally lower diffusion rate, but in practice N2 has a slightly larger atomic diameter, so the diffusion rate is minimally lower for N2 - very minimally. The 3 to 4 factor is made up, just like all of the "Nitronized" marketing hype. The people pushing this stuff can't be bothered with scientific facts. They like to employ scientific terminology, but it doesn't have any basis in real science.

Tom

 

Everything I see says yes O2 diffuses 3-4x faster than N2 thru tire walls, but who cares? it is not of much practical significance because nobody is filling their tires with 100% O2. Why can't the technical answer be (what I believe to be the truth) that O2 diffuses 3-4x faster than N2 thru tires, but this diffusion property of N2 is of minor practical siginificance in tire maintentance and does not justify spending extra for pure N2?

 

What reliable scientific sources state that O2 diffuses thru tires 3 to 4 times faster than N2? None that I am aware of.

The 3-4 times claim is significant because it goes to the heart of the integrity of the N2 peddlers.