I have done only one really flat one at a time or topped off several low ones and the gauge never moves. I suppose a guy could figure it out mathematically. 80 cubic feet of air at 3,000 psi is a lot of air. Just breathing it diving, I’d get at least a couple of hours on a tank. Inexpensive to refill it at the scuba shops as well. A kiddie pool took longer to fill than any tire I’ve filled and a big pool would probably drop the gauge down less than 500 psi. I suppose that a tank isn’t as light or convenient as one of those little cigarette plug tire inflators, but pretty portable and way faster I’m sure. That tank has saved us a bunch of times just to inflate a low tire with a nail in in with enough air to get it to the tire shop.
