Just curious. Seems like there would be much less chance for both issues without the need for working the throttle so much. I'd guess the throttle in the 5AT cars is exercised about one fourth (or less) as much as in the 6MT cars.

Each time the throttle is let up, the drop in intake manifold pressure tries to pull oil past the rings and valve stem seals. Also, the little motor in the throttle body has to move the plate around.

 

wtf...and no

 

double wtf

 

Curiosity killed the cat....and I'm not aware of many problems with TB's in the Z, although I will admit mine died this past summer. Almost 100k on it at the time, quick and easy fix - $180.00. Have only heard of a couple of others though.
As far as the oil consumption question - do you stay up late at night to think of these things, lol?

 

Yes it seems that way to the casual observer.