With the recent cold weather, my TPI sensors have gone haywire. I am sure a lot of other car owners experience the same thing. On cold mornings, the low pressure alert comes on and says all of my tires are low. From what I understand, one of the reasons (if not the only one) they put nitrogen in new car tires is that this gas doesn't fluctuate in pressure like oxygen. So, I got on the phone and called several tire shops. Neither NTB, Pep Boys or Discount Tire has any. Where the heck do you get this stuff?

Both nitrogen and oxygen pressures respond to temperature change. Roughly 1 psi for every 10 degrees temp change. Read this article about this issue.

Bottom line — Check your tires psi with a good pressure gauge once every week or two and you will be good.
Pure nitrogen is pretty much just something to sell. Minimal benefit.

https://www.edmunds.com/car-buying/should-you-fill-your-cars-tires-with-nitrogen.html


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Costco tire center has it. Also car dealerships

yep, Stealerships love to rip people off with nitrogen for $200. I refuse to pay it. I negotiate my best deal and when they try to add it I say take it off or I walk. It is just one of their worthless add ons to pad their bottom line. They will try to feed you full of all kinds of BS to get the money out of your pocket. Just air your tires up to the proper inflation numbers when cold and reset the TPMS if you have to. My sensors are set at 46 lbs because I am running BFG KO2s. I deal with this normally with the first cold snap. I have to wonder about the process of filling tires with nitrogen. Do they suck all the air and create a vacuum? If not you are getting a mixture of regular air and nitrogen.

Nitrogen is not affected by temperature changes. It is an inert gas, that's why it is used exclusively in airplane tires. As far as car or trailer tires, use compressed air.

yep, we are not landing jets. I wonder how much money has been made up selling folks on nitrogen. One time I just let the sales dude rattle on about the benefits and wen he finished I just insisted that he remove the charge. Reply was "but we put it in all of our tires". I said I don't give a rat's behind what you do but I am not paying for it.

Ambient air composition.....78% nitrogen...21% oxygen....MONEY GRAB!!!!!

The Costco in Plano has it outside their tire center. It is free, and it is self service. Just screw it on to your tire, set the pressure you want and let it run.

So does it suck the air out and replace with nitrogen? Is it free to non members?

it does change with temp
https://www.getnitrogen.org/sub.php?view=nascar

They havent gone hay wire you just need to add air. Your probably gaining 2-3 psi when you drive and warm them up turning off the tpms making you think they are bad when on again in the am.

What did you do before we had TPI sensors? Yeah....do that.

When I bought my truck they tried to stick me with paying for that, told them no and threatened to walk. They took the charge off. I had a flat that had to be patched, so I have one tire with just normal air. According to the pressure monitor I can tell which one it is on cold mornings even after several rotations. That one is usually 3-4 psi lower than the others but comes up to the same after a little driving.

I work in the Semiconductor industry so let me give you a little insight to using N2 in tires. It's not the N2 or any other gas used to fill the tire but it is the amount of moisture in the gas that makes the difference. The reason that N2 is used is that it is the highest % of gas in the air we breathe so it is cheaper to extract by volume. When they do the separation in the cold box, the process also removes a considerable amount of moisture at the same time. Then depending on the moisture content desired (PPMv or PPBv), they will remove additional moisture via purification of some sort (heated, nickel getter, etc.).

Most tire shop air compressors will have a moisture content of 10 ppm to 25 ppm and then add in all the moisture they add when they mount a tire, so you do have a lot of moisture in your tires.

In the tire, the moisture will either expand or contract depending on the temperature changes (this is where the 10+ ppm compared to the 1 ppm moisture content comes into play). Cold mornings, that is why the pressure is lower. Roll down the road and the tire temp heats up (friction) and the pressure raises. Simple physics.

When using N2 with a moisture content of less than 1 PPM, there are less of the temperature/pressure swings happening in your tire which will affect your MPG's as well as tire wear. Little known fact - the reason that they fill a passenger tire to 32 psig is because they know that the tire pressure will increase as you drive so they fill it at less than the desired operating pressure of the tire and hope it comes close to that pressure based on your driving habits and other contributing factors. This is the biggest issue as far as tire wear, safety and MPG's because they are purposely under inflating your tires.

Drive around on a cold morning/short trip and note your MPG's and then do the same on a warm afternoon and you will see a significant improvement in MPG's with the tire at a higher pressure. Now imagine that you didn't have moisture in your tires creating these pressure fluctuations and you could set the pressure of the tire for the best MPG's and wear characteristics (let's assume 40 psig) for your tires. Let's assume that you get 20 MPG's in your vehicle and 2 MPG's better with a constant tire pressure and you drive 10,000 miles a year, you will buy 500 gallons (20 mpg) compared to 454 gallons (22 mpg) of gas which at $2.25 per gallon average is $115 in savings per year (BTW - mine is closer to 3 mpg in my Jeep Grand Cherokee and 2.25 in my Tundra but the math was easier at 2 mpg).

Speaking or tires lasting longer, you will have less wear on your sidewalls (under inflation), corrosion of the steel belts internally and the decomposition of the rubber internally and finally the road contact surface is more consistent so your thread wears more evenly. So if I get another 6 months to a year out of a set of tires, that is a huge savings.

So now that $200 that you wouldn't spend based on ignorance is costing you a lot more money in additional gas and the tires wearing out quicker.

So yes, I have N2 in my Jeep, Tundra, wife's Explorer and tandem axle boat trailer. I feel I save a lot more money by having them filled with N2 over the 10 years that I have done it and been watching the cost comparison between N2 and not using N2 but the biggest plus is that I am less likely to have a tire failure such as a blowout at highway speeds which is worth more to me than $200 dollars.

It also helps that I have a 10,000 gallon liquid N2 tank out back at work that is around 0.5 PPM/500 PPB and have vacuum pumps to extract the moisture they use when they mount a tire (bet you didn't know that is what costs the most and is important to do before your fill it up with the nitrogen).

And if it's good enough for NASA and Nascar, it's good enough for me. Heck, some people even call me 'BlueNitrogen'.

Interesting...thanks

Even if you don't pay the dealership for the nitrogen in your tires, you are still getting it. They are not going to deflate your tires and then reinflate them with something else. Regardless of having the tire inflated with nitrogen, you are still going to have oxygen and moisture in the tire because the atmospheric pressure air that was in the tire when it was mounted was never removed. Nitrogen in tires is purely a profit grab from the dealer. It does not cost $50 per tire to fill a tire up with nitrogen gas. You can go to a AC supply shop and buy a tank full of nitrogen for less than $200.

Incorrect. When they fill a tire with N2, they evacuate the tire with a vacuum pump to remove the air and (more importantly) the moisture before filling it with the N2.

Google is your friend - https://www.nitrofillus.com/benefits-nitrogen/nitrogen-vs-air/

I have never felt the need to google anything regarding nitrogen in car tires, because common sense tells me that $200 to to do it is a rip off.

From what I read about, the tire is evacuated down to 3 psi (a vacuum will damage the tire according to tirerack), so by my math, it looks like about 1/5 of the "bad" air is still in the tire. Getting more oxygen and moisture out of the tire is certainly not a bad thing and probably will slow the rubber oxidation in the tire, but it doesn't seem like it makes any difference in car tires that get replaced every few years.

Tirerack.com, Consumer reports, and various other reliable sources have literally written articles that say nitrogen in tires is a waste of money, so I would not characterize people who don't want to spend $200 on nitrogen tire filling as ignorant.

I am not going to write any more on this subject. Like most other internet debates, this is nothing but a huge waste of precious pixels.

Wow, I buy a tank of nitrogen at my AC supply hose for around $18

Yeah, we keep a 300 cuft. in the shop as well, our local guy is between $17 and $18 on it. The only tires I put it in are on the A36, even then its not really necessary.

Pv = nRT. It is a law. As mentioned above, it is about the moisture in the gas being put into the tire.

Just add 2 extra pounds of air toy your tires and your tpm light will not come on.

78% of air is nitrogen. Oxygen at 21%. Argon is around 1%. Percentages change as moisture is added.

I would not trust the flunkies at a dealership to do it correctly. When I was getting free oil changes they could not even get my air pressure correct. I had to chalk my tires just to make sure they rotated them. Dealerships only care about one thing and that is how they can pad their bottom line by selling over priced and unneeded services, like over priced air filters, to the uneducated.

If you know someone who does AC work he will probably have a tank. Dealerships will rip you off like it is some special thing and I guess it is if you don't have access. A small cylinder of nitrogen runs about $11 unless it's medical grade.

I've got it! I'll drive to Arizona, where there's almost no humidity and have my tires emptied and refilled. Snake oil.
There's a sucker born every minute: PT Barnum IslandJim

Some on here will disagree but it definitely snake oil at $200 from the dealership. There is no way you are going to come close to recouping that cost.

I sell it for $16.00 here but I've never tried to see how many it would take to fill 4 tires.

My TPMS alerts only go off a couple times a year.

The first time when the first "real" cold front hits and again in the Spring (sometimes) when the temps start to climb.

Why would they go off in the spring? PSI in tires should go up when temps get warmer.

Nitrogen in my race car tires gains less psi than air BUT it still gains psi.....

Nobody is filling their tires with Oxygen; the choices so for are naturally occurring air (with moisture) and Nitrogen. You would NOT want to put pure Oxygen into tires for several reason, one in particular that the Oxygen under pressure would increase the rate of oxidation of the tire materials.

To be accurate, you should be comparing "air" to "nitrogen" as nobody puts pure Oxygen in tires, nor would you want to. Oxygen is detrimental to the materials, and pure oxygen under pressure would degrade the tires faster from the inside. Part of the alleged allure for Nitrogen use is the reduction in materials degradation.