I noticed COSTCO gives the consumer the option of having their tires filled with ntrogen as opposed to regular air. I asked the COSTCO rep the advantages of nitrogen over regular air and he says the tires will maintain constant tire pressure. The nitrogen will no react to heat the way air does. Anyone one the board have their tires filled with Nitrogen. It just seems like one more variable that would remain constant when gauging accurate MPG's. Mike

I noticed COSTCO gives the consumer the option of having their tires filled with ntrogen as opposed to regular air. I asked the COSTCO rep the advantages of nitrogen over regular air and he says the tires will maintain constant tire pressure. The nitrogen will no react to heat the way air does. Anyone one the board have their tires filled with Nitrogen. It just seems like one more variable that would remain constant when gauging accurate MPG's. Mike
Yep, thats the new thing to do but my tire shop wants 5 bux per to do it.
A better hit is to fill them with Helium, reduces your curb wgt by 900 lbs :confused:

Yep, thats the new thing to do but my tire shop wants 5 bux per to do it.
A better hit is to fill them with Helium, reduces your curb wgt by 900 lbs :confused:

AHAHA i guess that would mean that ur X would be upside down if u ever decided to float it across a river.. ahahh!

yeah, dunlop tire filled my new tires with nitrogen and told my i can go to them ,for the life of my tires, to get refills and adjustments for free. sorry dont know pros and cons.

i prefer neon

Pure nitrogen resists heat build up and transfer in tires better than air, doesn't hold moisture as well as air, and wont leak out of tires as fast as air. Nitrogen is used in airplane tires and heavy use commercial tires. In these uses, the tires are usually recapped, so the inners must last a long time.

That being said, personal vehicle tires are almost never recapped and the tread will always wear out before the inner rots. Also, compressed air is cheaply avaible everywhere. The bottom line is that compressed air is perfectly fine for passenger tires. Nitrogen is certainly O.K., but there is no reason at all for the expense, unless you are the type that never ever checks their tire pressure (The nitrogen will leak out more slowly than air).

NASCAR uses nitrogen in their tires. They use a triple purge and fill. They do it because tire pressure buildup drastically affects the handling characteristics of the race car. I ws always under the impression that checking your tire pressure in a cold condition accounts for the pressure buildup when they heat up.

Checking you air pressure (cold or hot) has no effect on what happens to the air in your tire as the tire heats up. Heat and pressure will increase as the tire warms up either way.

A cold check is preferred as it is an easily repeatable baseline - and what tire makers specify.

Pure nitrogen resists heat build up and transfer in tires better than air, doesn't hold moisture as well as air, and wont leak out of tires as fast as air. Nitrogen is used in airplane tires and heavy use commercial tires. In these uses, the tires are usually recapped, so the inners must last a long time.

That being said, personal vehicle tires are almost never recapped and the tread will always wear out before the inner rots. Also, compressed air is cheaply avaible everywhere. The bottom line is that compressed air is perfectly fine for passenger tires. Nitrogen is certainly O.K., but there is no reason at all for the expense, unless you are the type that never ever checks their tire pressure (The nitrogen will leak out more slowly than air).

While most of what you said is true, I'll expound a bit...Nitrogen used in aircraft tires are required to be oil and moisture free to prevent rubber deteriation and the formation of ice at altitudes...but that's actually an addition to what the true purpose of Nitrogen in aircraft is for...it's used in various emergency systems on an aircraft that are routed through small steel/titanium lines where any moisture present over a long period of time can and will cause major problems at the wrong time and believe me...Nitrogen leaks just as fast as compressed air.. for 24 years me or my co workers have to verify pressure at least every 48 hrs...I definately wouldn't pay the extra money to use Nitrogen...compressed air has been good enough since 1845....

rippermac - thanks for the first hand report. All my info came via articles from Road and Track, etc.... The articles I read were pretty adament that nitrogen leaks out of car tires slower due to the size of the gas molecules, but I defer to your actual experience in the matter. :)

Are you military or commercial? I always thought aircraft mechanics have an interesting job.

Retired military times 22 years..civilian aviation now unemployed...definately wouldn't have traded the experience for all the money in the world...makes you appreciate the sun rising in the morn...

makes you appreciate the sun rising in the morn...

AHAHAH i just have a small bone to pick.. and this is off topic.. way off.. but why is it that military ppl get up so early?? i mean even after they've retired! I work for the missle defense agency and the ppl there get up so freaking early and go to work so freaking early even if they're already civilians! Is it REMOTELY possible for an individual to go through the military, retire, and revert back to waking up AFTER the sun has come up?.. say 9am or sO? Maybe im just lazy! AHAHAH!

My dad was in the military, always up at 5AM. I think they get up so early because you get more done in a day, and nobody's around.

ouuu good point! but hmm, i guess some of them should stay up till like 4 am then.. and then go to sleep afterwards, since no1 is really around at those hours ;)

AHAHAH i just have a small bone to pick.. and this is off topic.. way off.. but why is it that military ppl get up so early?? i mean even after they've retired! I work for the missle defense agency and the ppl there get up so freaking early and go to work so freaking early even if they're already civilians! Is it REMOTELY possible for an individual to go through the military, retire, and revert back to waking up AFTER the sun has come up?.. say 9am or sO? Maybe im just lazy! AHAHAH!

Wish I could stay in bed...but like I said after seeing and being in some of the crap I have...you learn to appreciate some things people take for granted...sun..shelter..food..water..the freaking birds and the damn squirrels and a/c :) I don't want to ever not experience the new day by sleeping....I'll sleep when the game is over ;) ;)

what time do you sleep?

The early hours for me are because I got used to PT before the sun comes up, once you do it enough it's hard not to. Yeah, you do appreciate all the things rippermac said. In some ways being up early is like the need for coffee, if I ever try to sleep in it feels bad, kind of like not having coffee.

what time do you sleep?

worked 2-11pm for last 2 years so my sleep is really farked...asleep by 3 awake at sun up...trying to wind down :)

Would anything happen if you had nitrogen filled tires and put regular air in it? Like say, for some reason you started to get a slow leak, and you were down to 30psi -- would putting 5 psi of regular air mess anything up or would the properties of it not affect it?

-Drew

If you add compressed air your tire will be fine...except now you would have some level of moisture mixed with the nitrogen....but it's no big deal...automobile tires have been using compressed air since 1845...and thats a bloody long time.....

Here a local Tire shop's webpage about using Nitrogen...

http://www.dunntire.com/InflationFuelSystem/

nitrogen doesnt oxidize so it won t eat at your rims like compressed air will alimuniun pit steel rusts and chrome plating will peel :thumbsup:

Another benefit of using N2 in tires is increased gas mileage ( a subject near and dear to my heart ).

N2 decreased tire heat and therefore rolling resistance.

Filling my tires with N2 is on my list of mileage boosters to try.

nitrogen doesnt oxidize so it won t eat at your rims like compressed air will alimuniun pit steel rusts and chrome plating will peel :thumbsup:

with the air around us composed of about 21% Oxygen (per volume) and without the use of an Oxygen reactant or a vacuum, there's a good chance that there will always be Oxygen present inside the tire...

with the air around us composed of about 21% Oxygen (per volume) and without the use of an Oxygen reactant or a vacuum, there's a good chance that there will always be Oxygen present inside the tire...

How so if the tires are purged of air ( with N2 ) and the tire pressure ( psig ) is grater than ambient?

How so if the tires are purged

How do they purge the tire of ambient air? Do they put the tire inside a vacuum chamber and then fill? Setting the wheel in the tire and filling the tire with N2 in ambient air will guarantee that there will still be Oxygen (and other gasses other than N2) inside the tire.

I dont know cauz I've never done N2 filled tires but removing all gasses from inside a tire is an interesting idea (that i've obviously have never seen) - with the atmopshere pressing, on average (at sea-level), just a tid bit over 14 and a half pounds per square inch, would an average (non agressive - no thick sidewalls) tire collapse in on itself at that pressure? or maybe the bead would probably pop inwards beforehand because i think the bead-tire lip (without locks) is designed to only support pressure from within the tire.

I use a 78% concentration of N2, works great, to die for:)

Another benefit of using N2 in tires is increased gas mileage ( a subject near and dear to my heart ).

N2 decreased tire heat and therefore rolling resistance.

Filling my tires with N2 is on my list of mileage boosters to try.


You'll only get increased gas miliage if you routinely let your tires get under-inflated. If you are meticulous about vehicle maintence, and always keep an eye on your tire pressure, N2 won't change anything, as the cross section of tire hitting the road will be the same.

I heard that Costco and some other places are just putting the green caps on the stems and telling the customers have nitro in their tires. I believe, so this is only my opinion, Nitrogen is only good for use in extreme heats (i.e.: drag strip, nascar, etc.) and not daily interstate driving. Just my opinion and a few of drag strip guys opinions.

-Drew

we used to use N2 all the time in pressure testing HVAC lines. Lets say you pressurized two identical pipes, one with air the other NC both to 100psi at 65 deg F. in the ambient air temp. Then it climbs to 100 deg. F later in the day. The one with air will expand more and thus give a higher pressure reading then the one with the N2. So this would give you a more stable tire press. reading up and down the scale

I heard that Costco and some other places are just putting the green caps on the stems and telling the customers have nitro in their tires. I believe, so this is only my opinion, Nitrogen is only good for use in extreme heats (i.e.: drag strip, nascar, etc.) and not daily interstate driving. Just my opinion and a few of drag strip guys opinions.

-Drew
I have been out of drag racing for many years, but yes when your dealing with such low press. like 8 to 10 pounds, a 1/2 to 1 pound diff could be the determing factor if you put your wailer back on the trailer. We used to always put a reflective cover on the tire facing the sun. Before they had bead locks we used to sheetmetal screw the rim to the tire. I just don't see how it could make such a difference on a daily driver. Just check your air pressure

The cover was pit use only

we used to use N2 all the time in pressure testing HVAC lines. Lets say you pressurized two identical pipes, one with air the other NC both to 100psi at 65 deg F. in the ambient air temp. Then it climbs to 100 deg. F later in the day. The one with air will expand more and thus give a higher pressure reading then the one with the N2. So this would give you a more stable tire press. reading up and down the scale
Rookie what you say is 100% true, have you tried running 78% nitrogen in your tires, it really works :D

No, but now that I have a part time job delivering medical supplies with my 97XLT and putting a lot of miles on it and how you believe in it. I am going to give it a try. I even still have a tank of it in the basement.

Lets say you pressurized two identical pipes, one with air the other NC both to 100psi at 65 deg F. in the ambient air temp. Then it climbs to 100 deg. F later in the day. The one with air will expand more and thus give a higher pressure reading then the one with the N2. So this would give you a more stable tire press. reading up and down the scale

Agreed!

May I ask: wouldnt a higher pressure tire equate to lower rolling resistance? I mean a solid rubber tire will outroll an air-tire any day due to less deformation as the rubber is pushed against the road under the weight of the car.

if an air tire increases in PSI as the temps increases, wouldnt it roll better at high temps/speeds than a more stable N2 filled tire? Of course there would probably be less rubber in contact with the road which would lead to uneven tire wear (and probably a decrease in traction off the line and when going around turns)

Maybe what we should really be doing is putting solid rubber tires on our cars ;)

Agreed!

May I ask: wouldnt a higher pressure tire equate to lower rolling resistance? I mean a solid rubber tire will outroll an air-tire any day due to less deformation as the rubber is pushed against the road under the weight of the car.

if an air tire increases in PSI as the temps increases, wouldnt it roll better at high temps than a more stable N2 filled tire? Of course there would probably be less rubber in contact with the road which would lead to uneven tire wear (and probably a decrease in traction off the line and when going around turns)

Maybe what we should really be doing is putting solid rubber tires on our cars ;)
Thats interesting you said that. In my old racing days that is exactly what we did to the front tires...over inflate for less rolling resistance and also to set the tires at such an angle to run of the edge. But what I'm getting out of this is that the steady pressure will give longer tire life.

But what I'm getting out of this is that the steady pressure will give longer tire life.

Ah yes good point!

Take today for example, I started my 7 hour run most of it driving. This morning I had 32# press. Tommorrow I most likly will have again 32#, But giving this N2 some thought, I can see where it could help in the long run. With that said lets take today in real time. 32# in morn before run 65 deg, later this day it got to 95 driving thru the town of Winchester Va. so now the press in the tire is no dought higer due to the expansion of air in the tire and that not counting the heat build up due to driving at 70mph. So now the tire is riding more on its center then haveing a good foor print. If you really want to get technical the tire facing the sun will pick up radiant heat and will even expand more then the shaded side. You can see where I'm going with this, so when I check air press tommorow morning befor the run it will say 32# cold. But in reality the pressures were up and down. I can now see that over the long haul with N2 you could expect better tire life, how that equates to Mpg I dont know

I can now see that over the long haul with N2 you could expect better tire life, how that equates to Mpg I dont know

Adhesion effect i think part of the focus... when tires get warmer, the tire material begins to soften up a bit which increases rolling reistance and traction - i guess why race tires have to be 'warmed up'. So I guess if your able to keep ur tires cool, it would have less rolling resistance.

Here's a great response from Eng-Tips.com about this topic:


The question about nitrogen in tires has come up in other lists on the web as well. Let me clarrify a few points.

1. Air is 78% nitrogen, N2, and 21% oxygen, O2. So even if you put air in the tire, it's already 78% nitrogen. Many of the so called nitrogen generators don't produce much more than 90% nitrogen.

2. At relatively low pressures (ie tire pressures) N2, O2 and water vapor will all behave as ideal gases, and follow PV=nRT. Pressure will increase or decrease to the same extent as the temperature increases or decreases regardless of which gas is in the tire. (Even at 300 psi, which is about 20 atm, there is little deviation from ideality.) Therefore the comments about N2 not changing in pressure as the temperature changes are without merit.

3. The rate of effusion (or diffusion) of a gas through a porous membrane depends on the molar mass and to some degree on the molecular diameter. N2 and O2 are almost the same size and N2 is lighter than O2 (28 g/mol vs 32 g/mol) so if either gas were to effuse out of the tire, nitrogen would do it more quickly. Luckily, tires are designed not to be porous membranes.

4. N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit.

5. The ozone, O3, in the atmosphere, which is a ground level pollutant, will do a great deal more damage to your tires than the O2 inside the tire. For instance, don't leave a condom out in the air in Los Angeles for a few days. It will develop lots of tiny holes and weaken.

spdracer22 says that dry air is preferably to air with a lot of water vapor. As a tire heats up, the very small amount of H2O present will be in the vapor state which may contribute to the overall pressure very slightly.

Several have suggested that N2 in a high pressure tank is more portable and requires no electricity. That would make sense, particularly for aircraft tires.

I find no reason to believe that N2 is going to produce a "better ride" or "better handling".

The bottom line is that for general passenger car tires or truck tires there is nothing to be gained (other than portability) by using nitrogen rather than air. The biggest gain will be $$$ by the companies that sell nitrogen handling equipment and the tire merchants that appeal to ignorant customers. And who is the biggest loser? Yep, the consumer.

here's the link:
http://www.eng-tips.com/viewthread.cfm?qid=120996&page=1

I guess that 78% throws a monkey wrench in everthing. When we did the testing on pipes it was 100% N2 and it really did hold steadier pressures then air. I would love to see someone for a year run one front tire on N2 that being sold to drivers and the other front tire just plain old air.

Just thought of something, I'm not selling the N2 thing but when they say 78% N2 that means if I'm thinking right, This means the 78% Is 100% N2 so its not the same as all air in the tire. Its only 22% air. which 78% is N2 Now I'm totally confused. :confused:

I guess that 78% throws a monkey wrench in everthing. When we did the testing on pipes it was 100% N2 and it really did hold steadier pressures then air. I would love to see someone for a year run one front tire on N2 that being sold to drivers and the other front tire just plain old air.

Just thought of something, I'm not selling the N2 thing but when they say 78% N2 that means if I'm thinking right, This means the 78% Is 100% N2 so its not the same as all air in the tire. Its only 22% air. which 78% is N2 Now I'm totally confused. :confused:
Rookie, was just pullin some chains, the air you breath, the air you normally use to fill your tires, is 78% nitrogen, just common everyday air

I dont want to really want to bring up a dead thread, but regular air we breathe is usually about 80% nitrogen. I've worked in the paintball industry for about 6 years now and we use both pure nitrogen and regular compressed air from a compressor to fill the tanks that power the guns. Nitrogen is usually cleaner just because when it is bottled they filter it pretty well. Any welding store can rent you a bulk tank filled w/ nitrogen for about $5 a month. They fill up to 6000psi usually. You could fill your tires for about a year on one tank. I usually check my tires once a month and they rarely need air. You could buy a tank from anywhere from $50 to $100 depending on where you look, and fill it to 6k psi for about $15 bucks. That could last most people 2 years worth of air.

All that being said, nitrogen isnt terribly more stable then compressed air, and I dont think you would notice a difference in it. Not worth the extra money, IMO.

Yep, me too.
Both my Ranger and GMC Suburban got nitrogen when I bought tires from Costco, they use real torque wrenches there too.
I wanted to use nitrogen in my scuba tank but can't find the proper valve assembly.