pigsticker

A tire dealer that's been in business for several years in my hometown is advertising in the local newspaper, that they will fill your tires up with nitrogen. The advertisment says that the military and NASCAR have been doing this for years. What would the benefits be to do this? They charge $15 for all four tires and if you have a flat they will only charge you for the flat repair and not refilling with nitrogen.

fb305svs

the pure nitrogen gas doesnt change volume as much as reg air does.. so therefore, in temp changes, your air pressures shoudlnt need to be changed.

Its used in racing because of how much different the temps are from cold to hot -

keeping in mind that our air IS mostly nitrogen - 70%? what makes the real difference for race teams is the MOISTURE content of the air. Since tire temps routinely run at or above the boiling point of water, the moisture in the air turns to steam, which in turn causes the pressure to go up, since the extra volume needs a place to go.

Is it worth it? i dunno, not in my opinion, i would rather just check my tires and take a peak at the brakes through the wheel to see how things are doing myself...

DartByU

Regular air permeates through the tire wall causing a loss of air pressure over time, nitrogen won't do this, plus the oxygen in regular air oxidizes the rubber compounds in the tire and deteriorates the rubber from the inside, plus nitrogen tends to run cooler too, that's why NASCAR uses it so there isn't as much pressure rise as the tire heats up. It's a good thing to do, but a lot of places over charge for it.

V8 Slayer

Fill up with helium , you start floating

Inwo

All the benefits of nitrogen are lost if you ever had your tires filled with anything but nitrogen in the past. If you get some new tires and a can of nitrogen from some supplier (MUCH cheaper than the $15-30 I've seen at most tire shops) you would be able to reap the benefits, otherwise don't waste your cash. Heck, half the time the tire shops that 'fill' your tires with nitrogen just top off the air pressure.

nape

iTrader: (1)

Not completely relavent to the thread, but back in the 60s, Smokey Yunick experimented with running Nitrogen to see if it would help their problem of blowing tires.

He figured out that normal air was actually better because the moisture content of the air would actually turn into steam, evening out the hot spot in the tire. It would only last a few more laps, but that was what he observed.

FYI

paulo57509

Costco now uses nitrogen to fill tires. They then install a green valve cap to denote such.

For street driven vehicles, I think it's a wash. It's not like I'm racing at Daytona and I'm going to go out of my way to find nitrogen to top up my tires.

paul_huryk

Does the nitrogen increase the load rating of a tire?

Would be interesting to find out.

iroc-si

No it doesn't affect the load rating.

Nitrogen is used for reducing how the temperature affects the pressure. It has little application in drag racing I would think, as the run is so short, however on circuit racing the temperature varies a lot, especially during full course yellows etc.

Si.

MrDude_1

because you will never notice a 1-3psi diff in tire pressure on the street..... no.



total waste of money.










now if you were RACING and had the car dialed in to the point where you were tweeking airpressure by the PSI, then YES... its more repeatable......

forever3

I have been told that in normal driving at interstate speeds, your tires temperature will increase 35 or 40 degrees over outside temp. That doesnt sound like much, but for every 5 degrees temp increase, you will gain 1 psi in your tire. Take, for example this time of year, average temp is around 45 degrees. I drive 20 miles to work, 10 of those miles on the interstate. I leave the house, my tire press is 32 psi. I get to work, I am around 40 psi, and that is not accounting for warmer days, etc. If you air your tires up and it is 35 degrees, then what is your pressure gonna be going down the interstate on a warm day!!??? NAw, tires cost too much, and with the added life you will get from your tire by keeping an even air press in it throughout its life, I would say it is VERY worth it. Even if you now have air in your tires, changing that air to nitrogen will still maintain air pressure, and slow wear on the tires that you have left. Sooner the better. Spring is coming up, and those pressures are gonna fluxuate dramatically with air in them.

I have been doing aviation maintenance for over 13 years, including 4 years Air Force. The ONLY gas I have seen go into aircraft tires is Nitrogen. As far as I know, the aviation industry started using it in their tires (as well as the pneumatic systems, precharging hydrauilc accumulators and reservoirs, etc.) eons ago. I have been using it for years, and I can honestly say that it does make a noticeable diffrence on those way cold and way hot days, and going by mileage, I would testify to about 7,000 additional miles on my tire life. (Same car, same brand / size tire, same driving conditions, etc.) It made a beleiver outta me, but thats just my experience.

Apeiron

The rule of thumb is more like 1 psi for every 10 degree change in ambient temperature. Most of this is because of the vapour pressure of the water trapped inside the tire. If you were to put a dessicant inside the tire, or use an air compressor with a dryer, any difference in the change of pressure with temperature between a nitrogen filled tire and a "dry air" filled tire would be minimal.

The real benefit of nitrogen to the longetivity of the tire comes from slowing down the rate of oxidization of the rubber from the inside out.

iroc-si

Are you remembering that the stated pressures for the tyres on your car are for when the tyre is cold. Therefore they have already taken into account that they will heat up, and have a higher pressure. So if you put nitrogen in them, surely you have to then compensate for the usual air expansion by running them at a higher pressure, all the time....

destinz28

I just got out of the USAF I worked on airplanes which we filled the tires with nitrogen if possible only because nitrogen is a dry gas. Moisture can do alot to tires but most of all in airplanes the through different altitudes tire pressure can change if moisture is involved. I don't know if this helps.

forever3

I don't know about oxidation from the inside out, or even 1 PSI per 10 degrees, or 5 degrees. All I do know for a fact is that during my commute, my tires increse pressure 8 psi from when I leave the house to when I get to work, (I checked, cool and warm days) and I am not sure if the tires are heating up 80 degrees, or 40 degrees (didnt take a temp reading of the tire), but the expansion and contraction of the press in the tires will change the tread wear from cold to hot. A constant pressure will keep the same tread on the pavement all the time, which is where I thought the longer tire life was. The tires didnt oxidize on the inside causing me to replace them, the tread wore out.

If moisture was the biggest enemy, wouldn't you have more corrosion in the rim? Even if you dry compressed air, the smaller molecules will still allow air to seep out, where the larger molecules in nitrogen will not. Reguardless of all that, bottom line is that nitrogen is worth every penny in the long run.

And yes, I was told my a couple diffrent sources that you wanna up the press with nitrogen. I run mine at 40. Good wear pattern (rotate every oil change), and good solid feel on pavement, in town or interstate.

doc

MAN!!!!

There is alot a crap listed here.

Nitrogen is used in NASCAR because Nitrogen is dry, no moisture! With dry nitrogen, the tire pressure biuldup is reduced. Therefore, making the tire behavbior more consistent over the entire run of a set of tires.

Air contains water and due to the typical increase in tire internal air temps, the tire pressure increases a fair amount, over our temp ranges in normal driving, there is 0.9psi increase in tire pressure for every 10*F increase in internal temperature.

Nitrogen is street tires is a crock, waste of your money.

BTW: Smokey never found that out, because tire and nitrogen/air does not work that way.

What I said above comes from 29 years of tire industry & racing experience.

fb305svs

said it like the 5th post in.....

doc

Yes you did and I saw it. I posted because after your post there was alot of mis-information.

Sporkinator

In my experience in the paintball industry, we always used nitrogen in our guns because n2 is an inert gas. As temperatures go up and down, n2 does not increase or decrease pressure. The result was more consistent velocities at any temperature which meant more accuracy. What does this mean for tires? It would mean that in theory the tire would hold the same pressure no matter what the temperature was. Does it make a difference for street cars? Doubtfull. Besides, with these cars I would think that the occasional burnout does MUCH more damage than anything that normal air would ever do to a tire...

nape

iTrader: (1)

Go read his book if you don't believe me. He was running those tires a lot longer ago then 30 years ago, so his findings might have been a bit different then yours.

Not saying it's correct data, but what he observed.

fb305svs

i figuered ya did

IHI

iTrader: (1)

I will be changing my tires front and rear to nitrogen to experiment for myself, only thiing will be inconveience to have my air tank filled at the welding shop so if i do need to add "sir" to the tires I'm not mixing "air" with the nitrogen.

With normal air after a pass the slicks are normally 1-2psi higher than what I set them at in the stagin lanes approx 5 minutes before I pull into the water box. I also check my front tire psi before every pass and have noticed the front tires pick up a minimum of 2psi between rounds during the summer when the ambient air is hot and track surface is hotter. Typical staging lane temps are 100*-130* as measured with my temp gun depending on time of day and weather.

There was a video made by M/T I believe where they used infared video and documented a burnout to watch tire temperatures and how tire reacts during this process. Slicks reached peak temp over 400* in the burnout and just as the car staged was already down to 2??* cant remember the exact details so slick temps in drag racing see a HUGE variation start to finish and anything that can help that tire regulate so to speak will lead to improved consistency.

I'll see for myself what this will do, if it does nothing than I will go back to regualar air since it's as easy to get as walking out to the garage. But if it improves 60's and makes for less air up/air down in the pits/staging lanes then I'll be all for it. I talked with a few racers that said once they switched to nitrogen, they set their tires in the morning and never check them again as they will be the very same at the end of the day. Dont know if I'd personally try that since too much is on the line NOT to check them....kinda funny these were guys that never went many rounds....wonder if their 60's were never the same...hmmmm

doc

Smokey (a great man, racer, and innovator) ran on bias tires. Bias tires react to pressure changes in a drastic fashion. When the internal tire pressure increases in a bias tire, the tire tread radius will ALWAYS round out more than what is was. So if you are running on bias tires under racing conditions that create alot of internal heat, then nitrogen will help to keep the tire closer to its staring shape and performance.

Radial tires react completely different. Depending on how a radial tire is designed (in reference to the NIP (Natural Inflated Profile)shape), an increase in air pressure may increae, keep same , or reduce the inflated tread radius. In applications where the tire pressure changes only 2 to 3 psi, the use of nitrogen will have minimal effect. Steel belted radial tires do not change shape as readily as bias tires.

For street applications, just save your money and inflate your tires with free air.

VILeninDM

k, we just had a discussion about this at work, so I decided to do some searching of my own. First, 98% of everything on the internet about this stuff is pure marketing fluff. And then I found this post.

I have few comments/questions for the experts here:

1) How is pure N2 gas more dry than any other pure gas like O2? I agree that pure gas has no moisture compared to air, but "nitrogen is dry?"

2) N2 is NOT inert gas. This is a fact. Only elements on the far right of table of elements are inert. Nitrogen is not one of them. This is why each molecule as two atoms, hence N2. Why do people call it inert?

3) Nitrogen will not permiate through tire as must as air. Why is that since out of all air content (70% nitrogen, ~22% oxygen, ~5% argon, ~3% other), nitrogen is the smallest atom (14), and generally the smaller the atom will permiate through rubber before larger ones. Oxygen is 16. Helium is 4. This is why those helium balloons deflate so fast.

4) Oxidation from the inside? What about oxidation from the outside? how come people don't generally worry about that. There is definitely way more moisture/water/snow/sun/acid rain from the outside.

Apeiron

It isn't dryer than any pure gas. The comparison is made against air.

Nitrogen gas is relatively stable and largely non-reactive, which is why it's described as "inert". The term inert doesn't necessarily mean it can't be made to react at all. Even the "inert" noble gasses you mention can be made to react (Xenon Hexafluoride, for example). There also seems to be some confusion between the reactivity of a single atom of an element, and the reactivity of a diatomic molecule of the element.

Atomic mass has little to do with the size of an atom, and molucular mass has even less to do with the size of a molecule.

Not much about it can be done from the outside. That comment referred more to commercial truck tires which have a much longer service life, by the way.

bouncefactor

Aas a very active paintball player I also look at it from thios issue. The advantage of nitro over normal; compressed air is simply it is cleaner and drier. I think you are being confused with CO2 as this is what all early paintball guns were powered by and twmperature greatly affects it.

The difference between comopresed air and nitro on a paintball gun is minimal. Nitro costs more and like I said tends to be cleaner/less moisture but if fill station has good filters (like say getting tank filled at a dive/scuba shop where air is intended for breathing) Nitro and compressed air for paintball is about the same.

trixxs

Not exactly sure bout this but did anyone consider the difference tire pressure fluctuation has on gas mileage?
Just a thought

VILeninDM

local tire shop started advertising on radio that if you go to them, they will fill your tires for as little as $5 per wheel and you'll save as much as 5 mpg on average a year.

Sounded like to me and few guys at work, that's why I started looking around and found this post.

naf

iTrader: (7)

A footnote if anyone's interested: Many heavy equipment manufacturers have recommended using nitrogen to fill tires for years to prevent the possibility of igniting the petroleum based sealers and tire beads used on the inside of their tires. The cat scraper comes to mind. Although in 10 plus years I've never seen or heard of one of these so-called blowouts.

I also expected Apeiron to use the ideal gas law (pv=nRt) to prove that one "dry" gas is essentially equivalent to another.

Apeiron

I would have, but then I'd have to use van der Waal's to prove that they're not. Close enough though.

The problem with moisture in the tire is that it isn't always in a gaseous state, it condenses out under pressure and then there's the change of the vapour pressure of liquid water with temperature to consider.

MAC_87

iTrader: (3)

My girlfriends' car tires were filled with nitrogen...she just got an oil change and they topped off her tires with normal compressed air.

will this do any damage to her tires?...

Apeiron

No

MAC_87

iTrader: (3)

mk, thanks ~