And that is why VR-1 is such a good choice. It has the additional ZDDP that some of our engines require as well as the latest synthetic additives that make today's oils so much better than oils of old.

Again, all modern oils have a significant amount of synthetic additives. They are obviously not straight crude. So, how much addition synthetics is the right amount? 10%? 25%? 50%? 100%?

Is there any real advantage to a syn blend or a full syn over conventional oils that have their own volume of synthetics? And given our decades and decades of success with the old oils, what would that advantage really be?

And I don't know about you, but I haven't experienced 'sludging' much the last few decades. Except maybe the Chrysler 2.7. And I go through a lot of cars and trucks every year.