What abuse? The engine has operating specs, and as-designed they park a oil spec or set of specs in the user manual. Going outside the spec in manual does not make the engine abuse the oil any more than if using oil that is spec'd in the manual. Hence, if the manual does not spec out a synth oil they it makes no diff at all if a synth is used or not.
I was using the word "abuse" in general and didn't expect it to be dissected like we are in the courtroom
as an example, with one of my cars, I can use 10W30 for 7500 miles under "normal" (not severe) driving conditions.
I have used 10W30 dino (CS) and 10W30 M1 EP in this car and both oils meet the spec. Per owner's manual, they should both be able to handle or take the "abuse" for the 7500 miles ...
However, i do 4000-4500 miles with dino and 7500 +/- miles with syn (M1 EP). Actually using syn saves me $ but that's besides the point.
Am I wasting $ by dumping Chevron Supreme dino or even M1 EP too quickly? Maybe!
If I was buying an otherwise identical car (please don't overanalyze identical) with 100K miles and records showed oil changes every 7500 miles one with dino and the other with a good syn (e.g. M1 EP), guess which car I would pick?
I Maybe changing my oil too quickly but in general, I think when push comes to shove, the syn can handle better than dino and one can do a longer oci with syn. That's all I'm saying and it's my current opinion based on my research (mainly from bistog).
YMMV