Haha, that's funny. Using simple math, forgetting all other principles, if you lost 20% of the air in a 35psi tire, it drops down to 28psi... ie under-inflated.

What, do you think the O2 waits in line for the N2 to escape first?

Like I said above, air is 78% nitrogen already, period. It all comes down to moisture content vs availability and cost. Nitrogen in street car tires rarely adds up to a savings unless there's a nitrogen bottle on your street available 24/7.

 

My point was that the 20% O2 in air would leak out faster than the N2, thereby causing tires filled with air to loose pressure faster than tires filled with only N2.

That said, I have a very hard time believing there is a big difference.

Mark

 

Oxygen? Nitrogen? A lot of interesting chemistry here; way more than I care to process. I'll just keep checking my pressures once a month or so and at least visually inspecting the tires every time I walk up to the car. Being the generally cheap Polish boy from the south side of Millwaukee that I am I will keep using the free air option when needed or until I come across a free nitrogen fill. I can't see how I would ever pay for that. That to me is like paying $1.50 for bottled water, which to me is the greatest marketing gimmick ever foisted on the buying public, but I digress.............

 

Free air, around here the station pumps are either $.50 or $.75. I have my own compressor, actual two, one big and a portable one that can plug into lighter or AC outlet.