Daniel Yu is a bit more than a chemist. He was the guy in charge of product development for Castrol Far East.
Before that, he worked for Cummins, and developed the tests they use to measure oils against their specs.
Before that he worked for (then) Ethyl Corp.
That was after he got his PhD from MIT.
And it took him several months at AMSOIL to really understand that it was possible to extend drain intervals without getting sludge!
>>>Not sure why though it would take him long to understand extended drains are possible??
Heck, there are a lot of folks on this board who can't seem to understand that-- and I've found an awful lot of them over the past 25 years.
It really isn't abnormal within the oil industry. Wasn't too many years ago when a Sun Oil rep told a friend "When the world is ready for synthetics, we'll have one." Think they finally came out with a semi-synthetic. The head of Valvoline commented a few years back that extended drains were not feasible with synthetics, because the same additive package was used as in the non-synthetic.
And Arnie's grandpa only used oil from a yellow can.