wiggy: a quick qustion for you if I may - years ago I used to do a lot of transpacific flying.
The uplift in the US was always JetA versus the more usual Jet A1 elsewhere. The rumours were that the calorific output of the Jet A was less than the A1 - do you know if that really was the case? ie. the howgozit was always worse ex-US than going.