Costco inflates tires with N2 (Nitrogen). How do they concentrate nitrogen?

Young guys that want the very best for their car, even if that car is an old beater.

When I was a kid we used to talk about winter air / summer air. Around November we’d ask guys if they’d put winter air in their tires yet. We didn’t even have to ask them directly, just talk about “winter air” to each other within earshot of some guy. Invariably, the guy would ask where to get winter air. Same thing in May; “got your summer air yet?”.

You can never get away with that with girls though. Young guys will abandon commen sense when it comes to their car, girls won’t.