Like you, that's above my pay grade. I do know that we've had good tight engines come from both Toyota and Honda in the past. And not every direct injection engine has fuel / oil dilution issues. And I also know that making engines rotate more freely greatly helps meet CAFE mileage requirements.I see that now. My apologies.
O.K. I direct my question to Billt460.
But Piston ring design is voodoo - like loudpeaker speaker design. Possibly a handful of those with truly great knowledge.
I will readily admit that am not one of them
But how bout my thoughts on fuel wash helping ring seal?
And the tighter a piston ring seals, the more rotational resistance that is going to generate with the crankshaft. These engineers have become victims of their own creation. And it's not something they can easily backpedal on to fix. So they do what they most always do..... They tell their customers, "It's "normal". When we all know, it isn't.