Great info. Thanks for sharing.
2 points:
1) One of my key objectives with oil would be the lowest viscosity at 40c. In that regard, while PYB is clearly a great oil, synthetic still has an advantage.
2) Related to that point, more and more manufacturers are spec'ing 0W20 or 5W20, these oils being even thinner at start up. Again synthetic wins out here due to being even thinner than dino at startup and providing more protection at the same viscosity at operating temp.
Thus, I think we should really be seeing more testing on those grades as opposed to 5W30.