Hi James
> At ~4500BTU I consider that too much heat for good fuel efficiency.
Not arguing. But there are times when you might make the decision that burning a bit more fuel is worth the speed. Sure, not every time.
I think the real bug was that Jetboil had these incredible claims for boiling time when they released their first stove, but those claims were totally fraudulent. We investigated them. Jetboil subsequently withdrew the claims completely.
> On gas pressure, note that everyone seems to think that boiling point is the absolute minimum.
>Not true. Water, for example, vapourizes into the air at all temps, even directly from ice,
> though it exhibits a very low vapour pressure. This rule applies to butane, n-butane, too…
>or any miscible liquids.
True, but one should add that if the vapour pressure is less than one atmosphere you don't get 'boiling' and no gas will come out of the canister. That is what boiling is: a vapour pressure equal to one atmosphere.
> Regardless of the starting temperature (at the gas pressure of the jet or regulator)
> there will always be some n-butane mixed with the propane.
Yes indeed, as illustrated by the article Stuart Robb and I wrote on this subject:
http://www.backpackinglight.com/cgi-bin/backpackinglight/effect_of_cold_on_gas_canisters.html
Cheers

