Me!
I believe there is some difference in the expansion rate of air and nitrogen. The question really is “Is the difference material for most drivers?” The answer is no. For someone who would consider a few tenth’s of a second over 500 miles important, it might help.
Well, there’s no difference in expansion rates between air (78% nitrogen) and pure nitrogen, both oxygen and nitrogen act as ‘ideal gases’ at these temperatures and pressures.
Don’t forget “blinker fluid”! On a couple of occasions, we have suggested to people that they have their blinker fluid changed.
;-))
The worst that I have heard about Nitrogen is that it doesn’t do any good. So if it were free, or just a couple of bucks, I would go with it. I wouldn’t spend more than about a buck a wheel–five bucks for the car. If it’s true that Nitrogen will leave the tire more slowly than air then probably the most important place for it is the spare tire!
BTW there is small bird called a snipe. It can fly very fast and make very sharp turns so it takes an excellent marksman to shoot one. Hence the word “sniper” for an excellent marksman.
Steve in NY
Speaking as a chemist, one difference nitrogen can make is that it’s less reactive than oxygen with the rubber on the inside of the tire. That’s a slow process, but could conceivably use up a psi or two of oxygen in a year. (Might be faster with racing cars - their tires can get HOT, I understand).
Presure change with temperature should be the same for air and nitrogen. Same gas laws apply to both oxygen and nitrogen.
Not sure why compressed nitrogen should have less moisture in it than compressed air, but in any case, anybody who is doing this should make sure to do it in a well-ventilated area. Ntrogen is not toxic, but it is an asphyxiant-- a fancy way of saying “it isn’t air,” and it is so close to being air that it displaces air in a closed room or container when it is released. Be careful.
High school chemistry. Hydrogen goes boom. Nitrogen no problem in tires and some prefer it but no big deal.
IMO, this is a STUPID trend. Jet aircraft usually use N2 in their tires because an emergency stop (say an engine faliure just before takeoff) usually generates enough heat to cause tires to burn and/or explode. Thus, an anoxic gas helps to put out such fires.
In a passenger vehicle, however, I’ve never heard of needing to bleed off sufficient energy as to cause a tire fire. (I imagine it could happen in race cars).
If you don’t anticipate making panic stops from >150 MPH, N2 is a waste.
I’ll be darned. So that means I can drop eight caps instead of four when I check the pressure? Will all eight roll under the car?
Um, because “moisture” is not nitrogen, and if the tire store buys a tank of nitrogen…
Silliness aside, purified gas can be bought specifically with low moisture content.
“Nitrogen atoms are larger than oxygen atoms” - no they aren’t. Oxygen is 8 on the periodic table, nitrogen is 7. Oxygen hangs around as O2, not just O, Nitrogen is also found as N2, so they aren’t even atoms, and O2 is larger than N2.
Also, who said if it isn’t Nitrogen it’s all Oxygen? It’s AIR, which is already mostly N and some O2.
How does it not leak as readily as air? It’s a gas, which makes up like 77% of regular air anyway.
You’d think N2 would be smaller, but it’s actually O2 that is very slightly smaller:
“Molecular size a bit tricky. As a quick comparison, we can use the covalent radius defined as 1/2 the distance between to identical covalently bonding nuclei. This is measured in picometers (1 pm= 1x 10-12 m). Nitrogen’s covalent radius is 75pm so the length of a nitrogen (N2) molecule ought to be 4 X 75pm or 300 pm. A molecule of oxygen (O2) ought to be just a shade smaller 4 X 73pm or 292pm. So an oxygen molecule is a little less than 3% smaller than a nitrogen molecule.”
Not that this make any difference, Nitrogen in tires is still an absolute waste of money!
I am firmly against the practice of putting nitrogen rather then air into the tires, as it would mean that James Bond would be dead of asphyxiation when he survived under water for a minute or two on tire air in A View To Kill For.