Thread: Kmart/Campmaster "Jetboil"

Well, if the can has more gas pressure than the appliance needs the regulator reduces the pressure output to what the appliance requires.

Gas ratio is somewhat critical though - propane burns a lot hotter and is better in colder temperatures as it has a much lower boiling point than butane (-45 rather than butane's 0) which means that as you drop below zero the "standard" iso-butane/propane camping cans aren't much chop. The reason these mixes are what you normally get as the standard is a little bit of safety among other things, as butane is a lot cleaner and less likely to create carbon monoxide if used in an enclosed space.

Some more technical places that sell more hard core gear often have 50/50 ratio cans which burn hotter but if you're planning on cooking in areas where the temp is much below freezing you're better to go with a liquid fuel stove otherwise the contents of your cylinder will separate into liquified butane which won't evaporate and be burned easily and the still-gas-state propane which burns as per normal.

The actual cost of the can may or may not be a factor in efficiency, as different shops often run different prices and it's sometimes luck of the draw in what you get. The mix is critical to performance, 70% butane 30% propane is the usual mix encountered but 50/50 burns hotter.