Originally Posted by alect
the only OW airline that i am aware of which has premium econ is BA - thus you would need to go via LHR and thus no AA miles.
Not quite. You can go LAX-LHR on AA (no premium econ) then LHR-PVG on BA (in WT+ = premium econ) with full AA miles all the way. Alternatively, you can go LAX/SFO-YVR on Alaska Airlines, then YVR-LHR-PVG on BA with AA miles the whole way. However, this is the wrong way 'round and almost twice as far as LAX-PVG which you can do, without premium econ, on AA/JL or CX, and presumably much more expensive too. If you must have premium econ, you're probably best off with United or Singapore, but no AA miles. Perhaps you'd get some better ideas in the AA forum.
Michael