Gas in tires

[walkeriot]

what's kind of gas that each F1 team puts in the tires? Should the gas have a high heat capacity to avoid/slow down the tire overheating?

and I heard the gas that Ferrari uses is different to others

How about nitrogen?

btw, the gas they put in is a combination of different gases or only one kind?

[redline]

Nitrogen is widely used even in road cars. It's supposed to be less temperature sensitive when it comes to holding steady pressure. It also does not contain water (unlike atmospheric air) which is good for metal parts and rubber itself. As we all know from spy affair Ferrari used CO2 to infalte their tyres but I wouldn't be supprised if every team had it's own carefully designed mixture.

[Mikey_s]

I started a similar thread ages ago;

viewtopic.php?t=1783

... if you use the search facility you'll find lots of discussion about this topic... however, the upshot seems to be that there doesn't seem to be much difference as long as the gas is dry...

Having said all of that, that transcript talks about Ferrari using CO2 - I guess it might just be worth a quick bit of calculation to make sure the arguments still stack up for CO2.

However, this type of thing shouldn't be too difficult to verify in the pits without having to resort to industrial espionage.... as highlighted in the thread above I think it would be quite irresponsible to re-paint compressed gas cylinders for safety reasons... there are EU safety codes for the colours, perhaps it's worth a look next time there's a pitwalk on TV;

http://physchem.ox.ac.uk/MSDS/cylinders.html

[syguy]

Ferrari leads the way again...instead of planting trees, store carbon in your tires. Where do we buy these carbon offset credits?

[walkeriot]

thanks a lot

btw, how can i search the topics in the forum (in the upper left coner)?

[Mikey_s]

I never even noticed the search box in the upper left... I always use the one just below the horizontal menu bar (just below the option for "News".

[persovik]

I believe one reason to use pure Nitrogen or indeed CO2 is to avoid the micro-leakage of smaller molecules. A tire inflated with air will loose more Oxygen than Nitrogen, and not only because of oxidation of the rubber, which in itself is bad enough. CO2 have got bigger molecules than Nitrogen, and should thus be even better for ensuring no loss of pressure due to leakage.

[Ciro Pabón]

thanks a lot

btw, how can i search the topics in the forum (in the upper left coner)?

I think you can't. The upper left corner box it's only for searching the site, not the forum.

To search the forum, you have to go to "Forum" or "Forum topics" and then "Search".

[ss_collins]

I can say know for a fact that CO2 in the Ferrari tyres is not the whole story.

[segedunum]

There are have been endless debates on what exotic gas Ferrari could be using. There were even reports that they may be using Argon, but the gas is just too exotic. Helium might also be a good candidate.

[mx_tifoso]

There were even reports that they may be using Argon, but the gas is just too exotic.

By "too exotic" do you also mean too expensive? Could you please elaborate on that?

[segedunum]

There were even reports that they may be using Argon, but the gas is just too exotic.

By "too exotic" do you also mean too expensive? Could you please elaborate on that?

I didn't really believe the Argon reports because the gas is just too expensive to get hold of and too rare for the purposes for which it is being used - unless Ferrari know something about how it works in the tyre that we don't and it is somehow essential for what they need. Why not Neon? It could be compression properties, how it works under pressure, how it handles excessive heat or a few other variables. It also depends on the characteristics of the tyres and also the set up of the car that would make any kind of different gas in the tyres actually work.

However, it has to be an inert gas of some kind, or at least a gas that is non-reactive. Ferrari would have needed to have done some serious experimenting to get something that would give them a serious advantage.

[megz]

Maybe we should try puncture a Ferrari tyre during a race and see if its insides glow?

[flynfrog]

i can buy a bottle of argon down the street for welding its neither rare nor expensive

[Ciro Pabón]

I strongly believe that any gas you could use in your tires, you should use for purposes of thermal stability, which is the factor that affects tire performance more.

I don't think controlling "flat tires" through control of molecule size is reasonable...

I agree with Flynn: I don't think we're talking here about rocket science, but about a simple measure to enhance performance a tiny bit (if the "gas thing" exists at all and it's not for "confusing the enemy").

Think for a second: the amount of pressure change you get from heat is several orders of magnitude greater than the decrease you can get from the tiny amount of air that can escape from the tire during the race.

I say: if you want to keep your tires inflated, check the pressure, instead of wasting 10 dollars inflating tires with nitrogen. An air pump costs 30 dollars and will help you save some gas. It's one of the first things you should buy with a car, if I may add.

As for rusting of rims, check the paint inside every time you change your tires. It won't kill you, it happens once every three years...

Now, if I'm right (incredibly, I've been known to make mistakes... ), then what we should take a look at is specific heat of argon, nitrogen and air, don't we?

Heat capacity is the amount of energy you need to heat something a certain number of degrees Kelvin (or Fahrenheit, be my guest). Of course, the units are Jules (energy) per Degree (heat).

Specific heat capacity is the same thing but for a certain amount of mass. So, you measure it in Jules per Degree per Kilo. For gases, you find that it's useful to measure in Jules per Degree per mol (a mol is a bunch of molecules). You can also measure the thing keeping a gas at constant volume or constant pressure.

Now, specific molar heat capacity for air, nitrogen and argon at 25º (sorry) at constant volume (which I think is the useful figure for a tyre):

Air: 29
Argon: 20
Nitrogen: 29

Do the math.

Besides, to put things on perspective, this are Joules per mole per degree Kelvin. This means, in few words, that we're talking about small amounts of heat.

Now, if you were really serious about keeping pressure constant, why on earth wouldn't you use a polymer to cover the inside of the tire, a polymer with a pore diameter small enough to contain the gas inside?

I dare to guess that's what the tire makers do.

Now, before tubeless tires, existed a thing called a tire tube.