My lunch break consisted of topping off the oil, filling the gas tank, and "mostly" replacing the air in my tires. I know, sounds weird, huh? Well, that last bit about replacing the air does.
I dumped the air, which is only CO2 at this point, down to about 15PSI in each tire. I used the air at the gas station to refill (35F/50R) the tires. Turns out CO2 is soluble with the rubber in our tires and escapes out to the atmosphere. It's true, look it up! I seem to loose about 1# a week and usually top off with my CO2 tank, again during lunch.
This is the first time I've used actual air to fill my tires in years, so I'm curious to see what happens. I'm going to start a separate thread on this and track my findings.