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?
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):
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.