He's saying that if the shear rate is high enough, meaning much higher than the shear rate of 1M/sec used in the standard 150C HTHS viscosity measurement spec, that an oil with a better base oil and less VII can have more dynamic viscosity (cP) under those super high shear rate conditions than a thicker grade of oil that has more VII.I’m confused, are you saying that Valvoline 0W16 is thicker than 5W30 and more like a European 5w30? And I’m also confused about the monograde statement and the group Vll base stock. Are you saying it’s mostly a PAO oil and therefore able to stay in grade?
But if the shear rate is closer to the 1M/sec shear rate, then an oil with a higher HTHS spec is going to be more viscous at that standard or lower shear rate.
I'd like to see calculations of what the shear rates are on engine components like rod and crank journal bearings, cam lobes to followers and piston rings at max piston soeed, and at what engine RPM those components surpass the standard 1M/sec shear rate used to measure oil HTHS viscosity. I doubt people cruising in normal driving conditions below 3000 RPM are pushing the shear rate much over 1M/sec.
At at a shear rate of 1M/sec used in the standard HTHS test, almost all xW-30 grade oils are going to have a higher HTHS viscosity than a xW-20 grade oil.