I was reading an older Tmax 530 review last night in an online Spanish motorcycle magazine, where the author was recounting the history of the Tmax 500. He casually mentioned in passing that the Yamaha "Tmax" was originally Yamaha "Twin Maximum" and was shortened for general use.

Never heard THAT before. Anyone else ever hear that???

I have herd something similar when the 2001 500 Tmax came out it had a long name and pretty sure it was Twin Maximum but can't be 100% sure. I read it in a article.

I always presumed that they called it T-max to bear some relation to their V-max (ditto X-max which relates to T-max).
I strongly suspect that the T-max name came first, and the 'Twin Maximum' derivation was dreamt up afterwards - probably for advertising purposes.

You could be right on that Mr Grumpy as the v-max 1200 was a real awesome drag machine as they still are and hold there own even in todays bikes.