@0x575446 @mnemonicoverload @Alice
yep. Also, do they still try to sell rubes on inflating your tires with nitrogen for an extra fee? That was a good one at least as far as a few years ago.
Funny, I never had a tire fail from oxidizing from the inside first…
@0x575446 @Alice @glasspusher I've had wheels leak due to rust pitting of the inner surface of the (steel) rim where it mates with the tire before. Obviously it's highly dependent on your local conditions though and not an issue at all with alloy wheels.
I certainly wouldn't let that rare occurrence convince me to put anything but regular air in my tires though and afik that's not really what they were promoting with the whole "nitrogen" thing anyway. My understanding was the point of it was supposed to be maintaining the same tire pressure regardless if the tires were cold or hot, as if it's somehow a huge burden to check your tire pressures when the seasons change. lol
@mnemonicoverload @0x575446 @Alice
really? Last I checked (so to speak) nitrogen expanded and contracted with temperature same as most other gases. Perhaps they were selling it as being bone dry? I could see how a bit of water vapor could affect things, but isn't that why air compressors have a knock out valve for removing condensed water in the first place?
yeah rilly check your tire pressure a few times a year, it's just common sense
if that's their argument, it's lousy. Air is 78% nitrogen as it is, 21% oxygen, which expands/contracts pretty much the same way.
A friend of mine who got suckered into it, they pushed it as avoiding oxidation/dry rot
I understand that it's morally reprehensible to let a sucker keep their money, but I will carve out an exception for folks who rip people off on their car work
@JamieR @mnemonicoverload @0x575446
Hi Jamie, thanks. I'm a chemist here and familiar with the gas laws and fugacity and PV = nRT and so on. Other than knocking out the water vapor, which would leave you with nitrogen, oxygen and a bit of argon, I don’t see a reason why pure nitrogen would give you more pressure stability than just bone dry air. Perhaps it's easier and cheaper to use nitrogen from a tank, which is bone dry, than to dry out air.
Any additional insight you have into this would be welcome. Thanks!
@JamieR @mnemonicoverload @0x575446
Hi Jamie,
Thanks. The article was OK, (it had one thing wrong, nitrogen can “support moisture”). At least they said nitrogen wasn't necessary to the average joe.
*but*
if race cars are using it I’m sure it has a benefit. Likely it's the easiest/cheapest way to get dry gas into the tires to avoid any pressure variations from water vapor going in.
Being race car tires are going to get a lot hotter a lot quicker than the average punter's, having dry gas inflating them is a Good Thing
@glasspusher @mnemonicoverload @0x575446 yes, it’s ideal for stabilising pressures in race cars - a couple of psi can make a huge difference in the way the tyre reacts/responds, and behaves, especially at high speed (150+ mph).
Of course, you can set the car up cold with probably something like a 99% accuracy rate, but that doesn’t help when temps drop (safety car period/yellow flags for example). It’s all about the tenths/hundredths of a second
Alice McFlurry 
mnemonicoverload
0x575446, Fifth Columnist
glasspshr
Indyzign 🏳️⚧️ 🏴