When they fill a tire with nitrogen, do they first evacuate the air so there won't be any oxygen or water vapor in it?

Racers use nitrogen rather than air because it's dry, and the absence of water vapor makes the tires behave more consistently. IMHO, racers began using nitrogen instead of air because they needed a compressed gas supply in the pits and bottles of nitrogen were easier to come by. I'll buy into the "no moisture" bit because water vapor is not as well behaved as nitrogen or oxygen, and racers need to push every detail they can.

Selling consumers on nitrogen instead of air is, in my opinion, bull. Air does not really diffuse out of tires. Unless there's a leak, the only change I've ever seen in tire pressure is from seasonal temperature. It won't make tires last longer, since the outside is still exposed to air. And the precision that racers crave is just not relevant on the street.

Nitrogen in tires is right up there with restaurants selling bottled water instead of giving tap.

Ken

 

do a quick search. all of your questions have been answered before.

 

The reasoning behind using Nitrogen, is not to save the tire but to save the rims.
nitrogen is an inert gas, as air contains moisture and corrosive particles. Remember Rubber doesn't break down and corrode until about your 10,000 year mark. Why tires go bald is do to wear and tear of driving. Now granted that the sun can do lots of harm to your tire, but that is the outside of the tire. As Nitrogen or air are on the inside. If you ever looked at an old car, say at a junk yard. You will notice that the outter tire is cracked and partly brittle, but if you remove the tire the inside is like new.

So in short Nitrogen is meant to reduce the corossive element to your rims and valve stem, not to preserve your rubber.

 

I've heard a bit of everything in each of the posts, but none of all.

I've heard that the idea behind it is that there is no moisture in nitrogen (n2) as there is in oxygen (o2). this means that heat will not affect the pressure of the tire.

additionally i've heard that the n2 molecule is larger than the o2 molecule and so the dispertion rate through the rubber is slower, and it will stay inflated longer compared to o2. (this is disuputed by wikipedia.org)

lastly the third benefit i've read about is that nitrogen won't oxidize the inside of your tires as oxygen will. if you read blackbelt's post (which i agree with) this seems like a bs reason to buy nitrogen.

nitrogen fills are about $10 a tire, if you consider the 3% (alleged) increase in mpg, the cost effectiveness of this doesn't really add up.

my .02

 

I just bought some s-03 and was wondering where to get them installed and walmart does it for $4.00/ tire plus someother things comes to about $44.00 total but not nitrogen. Glad I read this, Walmart here I come.

 

Had my tires replaced about two weeks ago and had them filled them with nitrogen... I would have never thought that it would make a difference, but I burned through 3 tanks of gas in the last two weeks that were all highway miles and did notice some change. Over the last 6 months I have averaged 23.8 miles per gallon when I burn the entire tank on the highway only stopping for gas.. I got 25.1 and 25 out of my last two tanks and 25.3 out of the tank I burned through today.. I still think it is a fluke and probably had more to do with air density and humidty for optimal engine operation than the nitrogen

 

Nitrogen in the tires will not give the car better performance. Nitrogen is larger than oxygen. Hence keeping the psi steady and if you happen to need to had air to your nitrogen filled tires you can add oxygen" regular air"

 

The advantage of using nitrogen imo is that it is drier than air and will not corrode the TPMS sensors as quickly.

 

unless you're racing IndyCars or Formula1 it's basically bullsh-t marketing on a street car

a) To do it properly you either need to pull a vacuum on the tire to evacuate out all the moisture and dirty air before inserting the N2 or you need two valves to continously purge N2 in and out of the tire for some length of time to accomplish the same

b) What are you going to do if you have a low tire and there's no N2 source around, which is an extremely likely scenario. Well obviously you're going to dump in dirty/moist air, which suddenly shoots this overly **** theory in the foot.

 

If i could get nitrogen in my tires i would but i am no going to pay the price they want to put nitrogen in. I will stick with checking my tire pressure every 3 weeks. For every 10 degrees colder you lose 1 pound of pressure in your tires. The only advantage nitrogen has over air is keeping your pressure stable so you dont lose gas mileage due to low tire pressures

 

I still see my tires pressurize the same amount at the track using N2 so I agree with you Team RX8 that it is hard to get moisture out of the tire once it is in. BTW I have a nitrogen bottle in my garage and I have an air tank that I fill up for use at the track. When I raced I would use the N2 bottle to run air tools. Very handy

 

Argon for the win

 

so when I eventually need to fill up my tires, it's ok for me to put regular air into the nitrogen filled tires?

 

think about it. not sailing against the wind here..


beers

 

Some places like Big O Tires charge $5 for the life of the wheel/tire. If ever you need to add pressure and there's no Nitrogen available, you can add air temporarily and you can come back to them and have them purge the air out and refill with Nitrogen. This migh not make sense if you have a wheel with single valve stems since you can't completely purge the air out but if you have 2 valve stems on your wheels like my NT03 +M, you can fill it up with nitrogen and evacuate the remaining air in the tire simultaneously.

 

Umm... no. Go back and reread your high school physics book.

Nitrogen is a gas. Just like any other gas it expands when heated and contracts when cooled. In a tire this means that as the tire heats up from rolling friction the pressure in the tire increases. This happens whether your tire is filled with air, nitrogen, hydrogen, helium, or whatever.

The benefit to nitrogen is that it is a dry gas (i.e., has zero moisture content). Therefore, the rate of expansion can be easily calculated. It is harder to calculate the expansion rate with air, because you must factor in the moisture content, which is constantly changing. Many race teams use nitrogen so that they can accurately predict tire pressures for a given temperature.

On a street car that never sees track time, nitrogen is worthless. You won't see any performance benefit (your tire pressure will still decrease when it gets cold, just like air), and you'll need to pay someone every time you need to adjust your tire pressure, unless you happen to have a tank of compressed nitrogen in your garage. Don't waste your money.

 

you're probably experiencing this as what others have stated: nitrogen is more stable than air, etc.

most autoxers know how fast temps and pressure changes on even one quick run. so you're just experiencing the higher psi gains that trickles down to your mpg gains.

whereas most streetcars filled with air should measure and add air "cold" for an accurate reading. nitrogen cuts that out.

like so many others stated with good analogy, its maybe only good to use for storing tires, and if you're an racer where consistent cold/hot temps and tire pressure makes a difference for you.

 

like stated above just a marketing gimmick for the mass media of the uninformed

 

Nitrogen is a gas. It is still subject to PV=nRT

Therefore, your cold pressure readings are still going to be significantly different than your hot temperature readings.

 

since when?!??! nitrogen is element number 7 and weighs 14 grams per mole, oxygen is atomic number 8 and weighs 16 grams per mole. Both nitrogen and oxygen form diatomic gaseous molecules in steady state. Guys seriously a little bit of basic chemistry knowledge would help the lot of you.

 

I like helium. It reduces your unsprung weight.

 

LOL at Helium!!!!! Honestly I work for a Toyota Dealer and its a customer preference, similar to conventional and synthetic oil but I know a few technicians who have used the Nitro Fill (Nitrogen Filler) and didn't have a significant effect. One technician stated that it made it relevant that his tires needed to be replaced because they leaked more lol, but I don't honestly know what to say. Its a personal preference in which you would like to use. I'd personally use whats free till that costs something (damn economy).

 

you beat me to it

 

the reason nitrogen is used in airplane and racing tires is due to the uniformity of the molecules in the gas. You could use any pure gaseous molecule to get the same advantage, you could use 100% CO2, you could use 100% O2, hell you could use a real complicated gas like bromochlorodifluoromethane (halon). At the end of the day pressure is pressure is pressure, thats the nice thing about gas, it obeys a set of rules (for the most part, using halon probably has a large van der waals effect), nitrogen is used because it is cheap and easy to purify, but isn't an accelerant like the other cheap and easy to purify gas is.

 

Any views on it? I have never used it but was having a conversation with my mechanic about it a few months back, and when he put my tires on he told me he filled them up with nitrogen for free. Anyone else use it? does it really matter? i mean if its free why complain. but is it really worth ten bucks a tire for everyone else? i cant tell since i just got my new tires, already it feels like a whole new car again. lol.