Here is a chart that breaks down the times and whatnot for various size tires to give you an idea of CO2 capability.
http://www.powertank.com/graphics/nc900.gif
A 5 lb tank will air up a 32" tire from 15lb to 35lb in 22 sec. You can do 13 tires at that rating. So a 20oz bottle should do 1/4 of that or 3 and some change tires. You could refill the bottle at any paintball or welding supply shop. I would recommend the 5lb bottle or bigger if you are using it for wheeling.
Reply With Quote