I was not disputing any of what you say about a relationship between lower weight oils and oil consumption. A problem does exist.

Only pointing out 5w30 has always been the recommended oil for the s cars (to my knowledge)

Alot is about meeting fuel mileage requirements.

Sure, it'll get 35 mpg and last 120K before needing a rebuild ($$dealer$$) instead of 32mpg and lasting 220K before it is worn out.

But hey, it got 35 mpg just like said it would. For a little while anyway.

No one cares about the customer with the prematurely worn engine. Out of warranty, not their problem. Indirectly planned obsolescence.

That's just another reason I drive a 20 yr old S car as a DD. 255K and counting.