Nitrogen filled tires?
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Join Date: Jan 2005
Location: Michigan
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From high school chemistry we probably all remember that air is 78% nitrogen, 21% oxygen and 1% misc. other gasses. From what I’ve read about filling tires from nitrogen, the benefits fall into three categories: less pressure variation as the tire heats up, less pressure loss over time, and longer tire life. The reduced pressure increase as the tire heats up seems to be attributed to the nitrogen being dry. There is no liquid water in the tire to change phase. Presumably, we can get the same benefit by using dry air. The reduced pressure loss over time is due to the tire having a lower permeability to nitrogen than oxygen. If you are regularly checking your pressure, this isn’t worth much. The longer tire life seems to get attributed to having the correct tire pressure and reduced oxidation of the inner layers of the tire. I don’t think many MINI tires are dying of old age (oxidation).
If someone offered me free nitrogen, I’d take it. But I wouldn’t pay much for it.
If someone offered me free nitrogen, I’d take it. But I wouldn’t pay much for it.
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Originally Posted by ripley
I hope this thread stays alive for a while as my new Kosie wheels have the dual valve stems for nitrogen. I'm interested in the benefits, cost, hassle factor and whether or not air introduced into a nitrogen filled tire creates problems.
ripley.
ripley.
When its readly available, it will be the way to go.
Alex
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Seen as every F1, CART, IRL and NASCAR team use Nitrogen in the tires - the benefits are very real.
The only person benefitting when you use it on the street is the owner of the shop charging $5/tire. $20 for all 4. Now that's a money making deal.
FYI, a large bottle nitrogen refill costs me less than $25 and lasts almost a season of autocross tire refills and tire changes.
Anyone need their tires filled with nitrogen? Only $4.99/tire!!
Unless the tire is completey purged of air, using a special setup (about $1000), the process is not reliable. We mount all our tires using nitrogen, and still purge each tire to completely remove any remaining air.
Funny thing is - I have never had problems with the inside of the tire wearing out or aging. Keeping tread on the outside though, that's a whole different problem.
Bones
The only person benefitting when you use it on the street is the owner of the shop charging $5/tire. $20 for all 4. Now that's a money making deal.
FYI, a large bottle nitrogen refill costs me less than $25 and lasts almost a season of autocross tire refills and tire changes.
Anyone need their tires filled with nitrogen? Only $4.99/tire!!
Unless the tire is completey purged of air, using a special setup (about $1000), the process is not reliable. We mount all our tires using nitrogen, and still purge each tire to completely remove any remaining air.
Funny thing is - I have never had problems with the inside of the tire wearing out or aging. Keeping tread on the outside though, that's a whole different problem.
Bones
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If you like spending cubic dollars on your street car for imperceptible gains, then nitrogen filled tires are for you.
If you track your car, it's different.
Mostly though, if your tracking a high horsepower, formula car like a Champ Car, F1 Car, IRL car, or even a stockcar, then it's actually of real benefit, seeing as so much of the suspension system is predicated on the deformation of the tire structure, and flex of the sidewall. The specific rubber composite, and the behavior of the tires at optimal temperature are the single biggest factor in the mechanical performance (I'm not addressing the aero setup) of a car like that.
EDIT: Ok, now that I read all the threads, I'm being redundant to Bones... but you get the idea.
If you track your car, it's different.
Mostly though, if your tracking a high horsepower, formula car like a Champ Car, F1 Car, IRL car, or even a stockcar, then it's actually of real benefit, seeing as so much of the suspension system is predicated on the deformation of the tire structure, and flex of the sidewall. The specific rubber composite, and the behavior of the tires at optimal temperature are the single biggest factor in the mechanical performance (I'm not addressing the aero setup) of a car like that.
EDIT: Ok, now that I read all the threads, I'm being redundant to Bones... but you get the idea.
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I am fairly sure that Col. Bobby is being sarcastic.
But just some info for those that may think this is a good idea. I know that teams have experimented with "lighter than air" gases for tires. I think the problem with hydrogen and helium has to do with molecule size, and the molecules pass through the rubber tire easily, therefore losing pressure.
Not to mention the flammability of certain gases. Remember the Hindenburg?
But just some info for those that may think this is a good idea. I know that teams have experimented with "lighter than air" gases for tires. I think the problem with hydrogen and helium has to do with molecule size, and the molecules pass through the rubber tire easily, therefore losing pressure.
Not to mention the flammability of certain gases. Remember the Hindenburg?
Originally Posted by Col.Bobby
If you're going exotic, might as well try hydrogen. Those heavy run-flats and S-Lites are just crying out for hydrogen.
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Originally Posted by Built-by-Bones
I think the problem with hydrogen and helium has to do with molecule size, and the molecules pass through the rubber tire easily, therefore losing pressure.
Nitrogen offers the benefit of having a predictable thermal-expansion rate. You can easily predict what your PSI delta will be between cold and hot, and this is part of why race teams use it. Preventing vapor is another key benefit, but removing that 1% of unknown gases that expand at unpredictable rates is the principle benefit.
If you're running a $1M car around a track and competing for millions of dollars in prize money, then why screw around with even one variable (other than the driver)?
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Wow, Nitrogen really is they way to go! (If you own a supercar)
http://www.motortrend.com/features/p...igh_speed.html
"Michelin: Traditional "air" is easily affected by temperature. As tire temperature increases the tire pressure expands considerably that changes the tire's contact patch and sidewall stiffness characteristics. Nitrogen is much more temperature stable than normal air so tire pressure remains much more consistent."
http://www.motortrend.com/features/p...igh_speed.html
"Michelin: Traditional "air" is easily affected by temperature. As tire temperature increases the tire pressure expands considerably that changes the tire's contact patch and sidewall stiffness characteristics. Nitrogen is much more temperature stable than normal air so tire pressure remains much more consistent."
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Originally Posted by Morris9982
Why not use helium? It's lighter than air or nitrogen and should reduce unsprung weight.
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You don't "produce" helium - you get it from underground mines.
The stuff is rare enough and important enough that the US maintains a strategic reserve of it.
http://acswebcontent.acs.org/landmar...roduction.html
One of its virtues is that it is completely stable and combines with nothing.
The stuff is rare enough and important enough that the US maintains a strategic reserve of it.
http://acswebcontent.acs.org/landmar...roduction.html
One of its virtues is that it is completely stable and combines with nothing.
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Originally Posted by chows4us
"Michelin: Traditional "air" is easily affected by temperature. As tire temperature increases the tire pressure expands considerably that changes the tire's contact patch and sidewall stiffness characteristics. Nitrogen is much more temperature stable than normal air so tire pressure remains much more consistent."
The positive aspect of N2 is clearly that the tire will stay inflated longer. Since the tire (initially) contains no O2, O2 will diffuse thru the rubber into the tire, partially offsetting the N2 diffusion outwards. This is like the Nike Air bladders in shoes - they filled those with sulfur hexafluoride, so that as the bladder stretched over time the inward air diffusion helped keep the bladder filled up. In this case, the SF6 diffusion thru the bladder was nil, unlike N2 or O2 thru the tire. Generally, these two molecules have similar diffusion rates, as they are both non-polar and about the same size.
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Originally Posted by inimmini
This sounds like BS to me.
Michelin: Heat management is an important factor since internal temperatures can quickly hit 300 degrees F at 218 mph. Michelin designed the Michelin Pilot Sport PS2 tire to limit peak internal temperatures to 250 degrees while evenly distributing temperature across the tread surface.
Motor Tend: What are the general tire psi requirements above 200 mph?
Michelin: Pressure should be no lower than 40-psi cold if you're planning on running at such sustained speeds.
Motor Tend: Why do many race teams inflate tires with nitrogen versus traditional air?
Michelin: Traditional "air" is easily affected by temperature. As tire temperature increases the tire pressure expands considerably that changes the tire's contact patch and sidewall stiffness characteristics. Nitrogen is much more temperature stable than normal air so tire pressure remains much more consistent.