The white papers written by Molakule in the Technical and White Papers forum are worth a read as well. "Tom NJ" also has a great write up on synthetics in that forum.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=postlist&Board=53&page=1
Those guys are experts. I'm just an oil geek.
Occasionally at bitog you will see replies to threads by Doug Hillary. He has worked in Oz for many of the oil majors (Castrol, Mobil, Shell, etc.).
-Dennis