Well, I went looking for information on the boiling point of CO2, and found that the boiling point is lower than I had thought (like -109). But, for purposes of airing tires using liquid CO2, the point is still the same. I found a chart which gave values for pressure at different temperatures, and the chart showed that CO2 at 31c (87.8 f) would produce 73 atmospheres (significant pressure - somewhere near 1,000 pounds I think). But, at -56c, it produces only 5.1 atmospheres (maybe 70 to 80 pounds). Minus 56 celcius is something like minus 68 degrees f, which is really cold, no doubt, but I have seen minus 55 right outside the door here, and the pressure drop from desert hot to winter cold is substantial. The point, I guess, is that there is a pressure gradient for CO2 that is driven by temperature as long as the volume remains constant, and the usable pressure of a CO2 tank decreases significantly as the outside temperature drops. If you have large tires and need to seat a bead, drive an air tool, or inflate a large tire, having only 70 psi at low volume might not get the job done. Be prepared to keep your tank warm in order to get proper performance from it.