Helium

[ConnClark]

Actually, if you could keep it from leaking out, helium in the tires would work better than nitrogen because it behaves more like an ideal gas. Personally, if cost wasn't an issue, I would be running neon in my tires. Argon though heavier might work better than nitrogen too.

weight of gas by liter at one atmosphere at 0 degrees C

nitrogen = 1.251 grams
neon = 0.8999 grams
argon = 1.784 grams

[ttoyoda]

I've heard of this whole nitrogen tire filling movement recently. What exactly are the advantages to using nitrogen as opposed to just regular air? I've been filling with air and haven't really noticed any problems with leakages or anything.

Some one gets to charge you money for what used to be free. Sort of like bottled water, really.

[LostCause]

Nitrogen is unnecessary. Who cares if the tires expand at an inconsistent rate? I don't have any wild chicanes on my commute.

I have had issues with water vapor as it tends to condense into the beads of my rims. A moist, oxygen rich environment has caused seemingly perfect rims to corrode from the inside out. A water filter on an air compressor would solve that issue, though.

Running lightweight gas is pointless. I'll take small gains, but saving 3 grams in rotational mass is futile.

- LostCause

[steensn]

You could put a whole slew of helium tanks in the back of your car!!! Maybe that would be enough helium to make it almost float!!!

[ConnClark]

Originally Posted by LostCause

Running lightweight gas is pointless. I'll take small gains, but saving 3 grams in rotational mass is futile.
- LostCause

The main point about helium, Neon, and argon are that they approximate an ideal gas. That means they would help reduce rolling resistance.

[LostCause]

Originally Posted by ConnClark

The main point about helium, Neon, and argon are that they approximate an ideal gas. That means they would help reduce rolling resistance.

Interesting concept.

I take it you mean that less heat will be generated with constant compression / decompression of the gas (i.e. it's [almost] reversible)? If that's the case, then it begs the question: how much does the air contribute to RR? My understanding is that tire deformation causes the vast bulk of rolling drag.

Without some sort of empirical test (e.g. tow bar w/ varying gases), I can't imagine what the gains would be. I highly doubt they would be noticeable, though. Call me an interested skeptic.

- LostCause

[Jon M]

NASCAR has been putting nitrogen in their tires for years - they don't do it for nothing.

[RH77]

I'm fairly certain they use Nitrogen in aircraft tires, due to the wide swings in temps (from a cold gear bay at altitude, to the "burnout" at touchdown). I think the rationale is the pressure changes due to temp variance as mentioned earlier with the attraction of water with compressed air use.

On a car, it's just an "overblown" safety feature. Honestly, we should be checking our pressures more often instead of relying on an inert gas for a safety margin.

RH77

[slopemeno]

A big part of the reason for nitrogen in aircraft tires is it doesnt have much moisture, and doesnt expand when the tire becomes incredibly hot, or in the case of an airliner, the now non-existent moisture doesnt cause condensation that can freeze at altitude.


And have you priced heluim lately? My job is supplying various medical, specialty, and industrial gases to a medical/research institution. Helium is extracted from oil wells, and since there arent as many new wells being dug, less and less helium is available. The price is getting so high for the better grades ( $350 my cost per H- or 200 cf cylinder) that labs are looking into purchasing hydrogen generators instead of buying cylinders of helium. Their equipment will accept either gas, from what they tell me.

You can probably figure the volume of your tires, the amount of lifting force (est .5-1 lbs max, if that?) , and choosing a slightly narrower tire on your next tire change will give you the same effect.

[Jon M]

Maybe you can power a hot air ballon from your exhaust for lift??????