I'm going to be adding on board air, and don't want to use a compressor, so I am looking at CO2 versus air (scuba tank) versus nitrogen. I'm interested in folks weighing in on the pros/cons. I don't care about arguments regarding which leaks out fastest or slowest, nor the possible risk of slight rubber degradation from the various gases. I'll be airing down (and thus needing to air back up) in everything from snow to sizzling deserts. I'm a certified diver (but don't own any equipment) so getting a tank filled isn't an issue. This is what I know right now:
CO2 pros: least expensive, greatest numbers of fills for a given size of tank
CO2 cons: valve can freeze up at high flows, tank should not get too cold, concerns about storing tank in a hot Jeep, most tanks must be upright
Scuba pros: high flow rates, not very temperature sensitive, can be used in any orientation, good to drive air tools
Scuba cons: expensive (relatively), tanks need frequent inspection
Nitrongen pros: perhaps more available than Scuba (welding stores and such) and cheaper, otherwise advantages same as Scuba
Nitrogen cons: least capacity for a given size
Seems like CO2 is the budget solution, Scuba is the top flight solution, but Nitrogen may have most of the Scuba advantages but may have better availability? The safety issues of CO2 in a hot jeep and the possibility of poor functionality in a very cold jeep may keep me away from it. Haven't yet found safety info on nitrogen cylinders, but I know Scuba cylinders do fine in the heat and direct sunlight.
Please add/correct my thoughts.