Nitrogen tires

[ConnClark]

Originally Posted by CapriRacer

And I'm going to try to answer the other question: Does the use of helium change any interesting tire characteristics?

I think the answer is "No!" Whatever the inflation medium is (short of something corrosive to rubber), it would have little effect in the way a tire operates. The only thing that might have an effect is thermal conductivity - and for an inflation medium, conducting heat away from the tire and into the rest of the air chamber is a fraction of the heat loss, and likely wouldn't have a large affect on the overall heat loss.

Actually helium being a monatomic gas will increase the bounciness of a tire. Also the lower mass of helium will allow the tire tread to deflect and rebound quicker as it will have less inertia. These two effects will reduce the rolling resistance slightly.

[oil pan 4]

If the inflation media has no effect on the tire then why did lexus argon fill tires from the factory, claiming the argon offered a quieter ride?

[ConnClark]

Originally Posted by oil pan 4

If the inflation media has no effect on the tire then why did lexus argon fill tires from the factory, claiming the argon offered a quieter ride?

Argon being a monatomic gas would also reduce rolling resistance. So would neon.

[some_other_dave]

Originally Posted by oil pan 4

If the inflation media has no effect on the tire then why did lexus argon fill tires from the factory, claiming the argon offered a quieter ride?

Marketing, duh!!

-soD

[CapriRacer]

Originally Posted by ConnClark

Actually helium being a monatomic gas will increase the bounciness of a tire. Also the lower mass of helium will allow the tire tread to deflect and rebound quicker as it will have less inertia. These two effects will reduce the rolling resistance slightly.

That's a really interesting claim. It doesn't sound right, but I am willing to be convinced. Do you have a citation to help fill in the gaps?

Originally Posted by oil pan 4

If the inflation media has no effect on the tire then why did Lexus argon fill tires from the factory, claiming the argon offered a quieter ride?

I did a quick google search and came up empty. Do you have a citation as well?

[oil pan 4]

Lexus didnt advertise that they argon filled tires.
Lets just say they did.
I believe if anything it was a cheap trick to help get the vehicle off the dealers lot.

Argon is fairly cheap and its used for insulating sound deading windows.

Would it do the same thing inside a tire?

[ConnClark]

Originally Posted by CapriRacer

That's a really interesting claim. It doesn't sound right, but I am willing to be convinced. Do you have a citation to help fill in the gaps?

Helium filled basketball?

also this makes reference to F1 teams ordering an argon nitrogen mixture
http://www.messer.si/import/GfLdec11.pdf


Here is a quote from the royal society of Chemistry on argon.

"The most exotic use of argon is in the tyres of luxury cars. Not only does it protect the rubber from attack by oxygen, but it ensures less tyre noise when the car is moving at speed. "

Argon


EDIT: Additional link to bounce of ball filled with helium
http://www.newton.dep.anl.gov/askasc...0/phy00342.htm

[oil pan 4]

Oh we werent spelling tyre correctly.

[CapriRacer]

Originally Posted by ConnClark

Helium filled basketball?

also this makes reference to F1 teams ordering an argon nitrogen mixture
http://www.messer.si/import/GfLdec11.pdf


Here is a quote from the royal society of Chemistry on argon.

"The most exotic use of argon is in the tyres of luxury cars. Not only does it protect the rubber from attack by oxygen, but it ensures less tyre noise when the car is moving at speed. "

Argon


EDIT: Additional link to bounce of ball filled with helium
Bouncing Basket Balls

Well, I was hoping for a link to some test data. It just doesn't make sense to me that different gases would behave differently as a pressurizing medium. I could see it if the difference was between a gas an a liquid - or there were different forms of gases, like a plasma. I'm just not buying that a tire would behave differently just because it is inflated with a different gas.

I did do a quick look up and found that Nitrogen has a thermal conductivity 50% greater than Argon, which is why Argon would be used as an insulator in double paned windows - and maybe why F1 teams would use it in tires (to try to retain the heat in tires on a cold day - or conversely, to prevent the pressure build up due to brake heat).

So maybe it would help RR by retaining the heat, but I am really struggling with this being a significant factor.

[RedDevil]

Argon is slightly (38%) heavier than air.
It will transfer more sound that air does; by that dampen the vibrations in the rubber.
A lighter gas would isolate sound better, but also dampen the vibrations less.

Even so argon is over 300 times less dense than rubber - and that's assuming 30 PSI in the tire. At such a low mass it can only seriously dampen harmonic vibrations over some time; not the kind you'd expect in a tire.

There are, as far as I can see, 2 ways in which tire noise manifests itself; outside through the air, and inside through the rim, axle and suspension into the bodywork.

Try as I might I cannot see how the gas in the tire inluences that.
So, if it does there is something happening that I'm not aware of. That is really exciting, I love to learn something new.

Tire noise is entirely testable, all tires have data on road noise.
If the fill medium has influence there should be noise data available.
If it doesn't I expect there will be tests proving that too.

So, where's the proof, one way or another?
I cannot find it. AFAIK there is no proof that it matters, nor that it does not. Either claim is unsupported. I just don't know, and think nobody really knows (proof based).
Prove me wrong on this - if you can

One thing - if it does matter, it would be interesting to know by how much it matters.
If argon would reduce road noise by 0.05% then it would matter, just not be worth it.