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Discussion Starter #1
I have it in mine since it was a dealer add-on. This is supposed to provide two major advantages over the use of just air: (1) reduce fluctuation of tire pressure, from season to season and from regular driving to highway/high speed driving, and (2) reduce tire/wheel wear/oxidation. I can say that (1) really works because I bought my van in December, which was about 40°F ,and just a few days ago (mid 70s), I checked the tire pressure again and it was exactly 33 psi as recommended in the owner manual. By contrast, I had to let out 3 psi of air from my CRV. While I will still check the tire pressure regularly, but I am impressed by not having to adjust the tire pressure over such a big change of temperature.

I thus wonder how many of you have nitrogen in your tires and whether you like it.
 

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I don't, but I'd take it if it was free. If I have to pay extra for it, then no way. Air is already 78% Nitrogen, so you are only really getting 22% more nitrogen if you fill with the pure stuff. Hardly enough to make a big difference.

It's more of a profit center for tire places.
 

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Discussion Starter #3
I don't, but I'd take it if it was free. If I have to pay extra for it, then no way. Air is already 78% Nitrogen,.
It is not the amount of nitrogen that matters but the lack of other stuffs, such as oxygen and moisture, that are found in the air. The air from the compressor may also contain oil.
 

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Tried searching? This Nitrogen in your tires topic has been beat to death a couple of times. We ALL have Nitrogen in our tires. LOL.
 

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***snip*** It's more of a profit center for tire places.
Also, a carrot to bring you back , and since you are there anyway, to have them ...

The advantages mentioned are real, but not significant enough for me.
 

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Discussion Starter #7
Sorry Admin, I usually search but this time I thought this topic was not popular ...

Before I leave this, I want to stress that I am not pushing the nitrogen thing, but I was very impressed by how well the tires hold the pressure over such a big change of temperature. If you do not want to check and adjust tire pressure on a regular (=monthly) basis, having nitrogen is for the peace of mind. To my knowledge, the industrial trucking companies put nitrogen in their tires, in part because of the hassle to check and adjust all those huge tires on a truck. The question for us is whether you do not mind checking/adjusting your tire pressure on a regular basis for safety and fuel economy.

Again, the issue is not how much more nitrogen you gain by using "pure" (95-98%) nitrogen, the issue is to really purge out the oxygen and moisture with an inert gas that is relatively cheap and easy to make and distribute. So the real advantage is to remove the oxygen and moisture so that oxygen no longer reacts with the rubber and rim. (Breathing pure oxygen is known to be "toxic" ...) Oxygen also exists the rubber faster than nitrogen so having nitrogen in the tires reduces pressure loss. The moisture in the tires cause the pressure to rise and fall according to the change of temperature, whether it is seasonal or caused by driving at high speeds.

"I can buy a portable nitrogen generation pump to replace ..." Nearly all nitrogen dealers offer free top off (and so does my Honda dealer) so you only need to do it once and owning a pump does not really save you money.
 

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Man, I don't know about all those claims. I mostly dealt with solutions and then solid state chemistry in my previous life, but I can tell you that your biggest exfiltration routes for any gases are the join between tire and rim, and through that wonderful Schraeder valve. Modern tire rubber just never has been really all that permeable to any of those major atmospheric gas components (N2, O2, CO2); it's designed not to be for obvious reasons, so said my former college roomie (his focus was polymer chemistry). As well, while the atmosphere isn't a perfect (read this as "ideal") gas, its components (including water vapor) do follow the ideal gas law quite well for our inaccurate shadetree mechanic purposes. Let's face it, even my reliable Orange Electronic TPMS with all-wheel full-time monitoring (on my 2003 Ody) doesn't have anywhere near the accuracy to get inside that.

Temp goes up, so does tire pressure. Temp goes down, so does psi. That's with N2 only, or with regular old water vapor-laced air.

Never saw a single peer-reviewed journal article proving that O2 will "exit the rubber faster than nitrogen", nor one offering a mechanism for this that we regular Joes could measure over a meaningful time interval. Actually looked for one once in the SCI. I think it's tire store industry hype.

"Breathing pure oxygen is known to be "toxic"..." needs some context. Yes, sucking on pure O2 at sea level no es bueno...because, it's ppO2 at 1.0 bar. What should be noted is that breathing O2 above about 1/2 bar ppO2 is not good for you, IIRC. Used to use pure O2 all the time while flying for the USAF, but that was at high altitude. 45,000 feet with a cabin altitude of about 18,000 feet required about 7 psi of pure O2 from the regulator, and this worked out to less than 1/2 bar, so it was not toxic, and kept us alive and alert. The key here is the partial pressure of O2 (ppO2)...is it greater than about 7-1/4 psi? Could be bad. Less than that? Not bad.

I think I'll get some of those green tire valve stem caps and put them on as a status symbol. The funny thing is, from a gas transport industry perspective, the standard color for oxygen is a green cylinder or a natural metal cylinder with a green top. Yet we cap the valve stems on our natural metal wheels with green caps to show they have N2 in them. Kind of strange! :)

Meanwhile, have almost 40,000 miles on a set of Michelin Primacy MVX4's on our 2002 Ody with plenty of tread left...and just good old regular air. I check it monthly since it doesn't have a TPMS, but we rarely have to add air. It seems I only add air with the first cold snaps of winter, and remove air if we have any unseasonably warm spring days.

If anything, it all makes for interesting conversation.

OF
 

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Discussion Starter #9 (Edited)
Never saw a single peer-reviewed journal article proving that O2 will "exit the rubber faster than nitrogen", nor one offering a mechanism for this that we regular Joes could measure over a meaningful time interval. Actually looked for one once in the SCI. I think it's tire store industry hype.
Consumer Reports actually measured it and those tires with nitrogen leaked less. Although the magazine cautions people whether this is significant if you have the good habit of checking and adjusting tire pressure regularly.

Tires - Nitrogen air loss study

Again I became interested in this after all four of my nitrogen-filled tires held steady for a change of nearly 30°F while I needed to let out 3 psi from the tires in the CRV.
 

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My former lab and error analysis self sees strange stuff with that article. First, it's not a peer-reviewed article; it's just CR. They didn't remove all of the variables nor tell us how they made assurances for doing so, but they did mention that the tires had 16,000 miles on them from wear testing...hmmmm. Second, it doesn't specify a proven mechanism for a leak path; they mention oxygen permeation in the Q&A with no proof for it, just heresay. Third, it still doesn't prove that any component of the gas can get through the actual rubber carcass of any tire in measureable amounts at the puny pressures car tires use for inflation. Fourth, they only tested once.

Also, with a 30-psi tire, and 1.3 psi being the difference in loss between 95% N2 and 78% N2...that doesn't prove anything, because that tiny number most likely falls within a standard deviation for their data set during the course of a year-long test. Not exactly the difference one would expect with all the hype about N2. Also, for us regular Joes, most store-bought tire gauges can't even get near that level of accuracy they sought to attain, let alone precision.

All CR can actually say, after looking at all their data, is that all tires lose air over time...which is what they eventually said in the end. Well, even our local Jethroes down at the local redneck hangout know that even without reading that article. I'm surprised CR wasted web page space for it.

I remain a skeptic of the benefits vs. costs espoused by the N2 crowd in the tire industry. I still don't buy it.

For those worried about O2-induced rubber degradation of the inside of the tire, how many of you ever saw a tire interior that went to the dogs before the outside of the same tire? ;) Given my problems with heat, road grime, UV and running over wildlife, I'm lucky to get 6 years on a set of rubber before I get antsy about the outside looks and go get them replaced.

OF
 

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Discussion Starter #11
My former lab and error analysis self sees strange stuff with that article. First, it's not a peer-reviewed article; it's just CR. They didn't remove all of the variables nor tell us how they made assurances for doing so, but they did mention that the tires had 16,000 miles on them from wear testing...hmmmm. Second, it doesn't specify a proven mechanism for a leak path; they mention oxygen permeation in the Q&A with no proof for it, just heresay. Third, it still doesn't prove that any component of the gas can get through the actual rubber carcass of any tire in measureable amounts at the puny pressures car tires use for inflation. Fourth, they only tested once.

Also, with a 30-psi tire, and 1.3 psi being the difference in loss between 95% N2 and 78% N2...that doesn't prove anything, because that tiny number most likely falls within a standard deviation for their data set during the course of a year-long test. Not exactly the difference one would expect with all the hype about N2. Also, for us regular Joes, most store-bought tire gauges can't even get near that level of accuracy they sought to attain, let alone precision.

All CR can actually say, after looking at all their data, is that all tires lose air over time...which is what they eventually said in the end. Well, even our local Jethroes down at the local redneck hangout know that even without reading that article. I'm surprised CR wasted web page space for it.

I remain a skeptic of the benefits vs. costs espoused by the N2 crowd in the tire industry. I still don't buy it.

For those worried about O2-induced rubber degradation of the inside of the tire, how many of you ever saw a tire interior that went to the dogs before the outside of the same tire? ;) Given my problems with heat, road grime, UV and running over wildlife, I'm lucky to get 6 years on a set of rubber before I get antsy about the outside looks and go get them replaced.

OF
Of course the small oxidation to the rubber is minimal considering that the tires and rims have other issues to worry about. We can debate all days why that is, but the major benefit of nitrogen that is being claimed, which I have personally experienced, is how well nitrogen-filled tires hold its pressure, which should readily impact ride quality, fuel economy, and safety. How do we explain that? Is it beneficial enough? Since I bought the Odyssey in December in 4x°F, the temp is now near 80°F, but the pressure in all four tire is exactly 33 psi (I have a very accurate gauge since I take this very seriously). Consistent with having the recommended tire pressure since I took delivery of the car, the ride quality has not changed from those cold winter days. I think this is quite impressive if it holds up throughout the year.
 

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Well, I'd look at that super gauge of yours. :D I've used N2 in a lab setting a lot for inert atmosphere requirements in a reaction vessel (way back when I had to). When temp was higher, so was the pressure on the transducer, and when colder, had a measured pressure drop. Plain old air did the same thing, too.

I guess you must have that "special" N2 that none of use regular guys have access to. :tongue: Still not buyin' it.

OF
 

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No way...sinbad, did you study p-chem, too? I thought I was the only HMG (huge mega-geek) on the forum.

OF
 

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Just short of a major, so I minored in chemistry.

Have you checked the entropy of your tires lately? :)
 

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Dude, another chem geek on the forum! I thought I was the only one who thought horn-rimmed glasses, pocket protectors, and short-sleeves with a tie at work were the latest in high style! :) I need to stop sounding like a butt; I do agree there are benefits to using any inert gas in a pressurized environment. It's good stuff for top-level pressurization of hydraulic accumulators, for use in shock absorbers, and of course, tires. How much of that chock-full-o'-goodness we get in low-pressure apps....I dunno.

Some days, it just feels THIS way:

People who use N2 in their tires (pic below; note the Ferrari 308 as stylish backdrop):




ME talking gas-phase chem on OdyClub, and being an N2 naysayer (note the chartreuse color of my workplace garb):



Funny that you mention S (entropy). I think entropy values and associated times should be imprinted on the sides of tires. We've got 6 and 8-yr old Michelin Symmetrys on my 1998 Accord (over 85,000 miles on these tires, as far as I can tell) that suddenly said sayonara...one of them, we'll say, is in a highly disordered state regarding its exterior sidewalls. Looking for replacements to bring the car's "S" values back down to acceptable levels.

OF
 

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Discussion Starter #18
Well, I'd look at that super gauge of yours. :D I've used N2 in a lab setting a lot for inert atmosphere requirements in a reaction vessel (way back when I had to). When temp was higher, so was the pressure on the transducer, and when colder, had a measured pressure drop. Plain old air did the same thing, too.

I guess you must have that "special" N2 that none of use regular guys have access to. :tongue: Still not buyin' it.

OF
Well, first of all, I am glad that this thread has invited some lively discussion ...

I was as skeptical as you are with nitrogen, but I am very surprised by its performance. BTW, I am a tenured professor who has a PhD and run a bio-medical lab funded by NIH. I thus know something about scientific research. Anyway, if I know how nitrogen works, I would have invented it in the first place and be making a lot of money now. As noted, nitrogen is used by racing for a long time and is currently used by the trucking industry so it does have benefits.

Back to my own experience, it remains possible that the dealer might have intentionally under-inflated the tires such that when the customers check the pressure at exactly mid 70, it will read 33 psi ... (If they can be this precise, we probably wouldn't have this much problems with cars) I will check the pressure again in mid summer, which will hit 100 here and see how the pressure held up, compared to those in the CRV.

My dealer will offer the nitrogen "free" if you install the tires there, if not, to get the nitrogen separately will set you back by about $100, or $25/tire, which is too high. If nitrogen does indeed reduce the need to adjust tire pressure over a long period of time, I think $5/tire may be a fair price.
 

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Well, first of all, I am glad that this thread has invited some lively discussion ...
Except, that all the other threads I mention too had similar discussions minus some of the too geeky chemist talk here.

Check the older threads out more livlier discussions.

http://www.odyclub.com/forums/52-2005-2010-odyssey/36196-nitrogen-tires.html
http://www.odyclub.com/forums/15-wheels-tires-suspension/11408-nitrogen-they-serious.html
http://www.odyclub.com/forums/15-wheels-tires-suspension/46391-nitrogen-tire-inflation.html
http://www.odyclub.com/forums/52-2005-2010-odyssey/67340-nitrogen-tires.html
 

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I'm just disappointed that nobody thinks my self portrait is worth any additional mention:




OF
 
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