Back to the topic .
As new additives have come out and when companies are willing to use them I think it's evident that old pao/ester oils can be beat by group III /pao oils w/5% ester . The other slack wax group III with ester makes for good oil but I do not see companies give them big additization due to cost in all probability .
Esters a name for many different types of it . I'm not a chemist but if making an oil I'd sure try to use some d-basic in there along with pao and slack wax or other group III . D-basic gives oils great lubricity even when used in small amounts .
It's funny , the better 5-10 synthetic oils out there come at 1/2 the price of some other high end oils .
Some of these gasoline engines with light ring tension and short piston skirts need the oil dumped fairly often anyway . One key to success is knowing if you own one of these engines then pick a suitable oil and oil change interval for it .