OK, after years of lurking, shon7 got me to register ....
First, Keg (with his magnificent contributions to sanity over the years), really means statute miles - SYD-LAX is 6600 nautical miles - or at least that's what the flight plan keeps telling me.
The simple facts are, that a 747ER can do about 16 hours flight time with 182 tonnes Jet A (that's what we squeezed on the other week). Even if SYD-LAX were 13 hrs, that still leaves you 2 hrs short to get to JFK. And why would you want to go to JFK with less than 15 tonnes?
To answer tinpis .... SYD-JFK eastbound IS the shortest way. To go the other way is into headwinds.
Rgs.