Take M1 for example - once upon a time I generally heard them to be something that could extend the drain interval. And of course you remember the days when manufacturers swore off synth, said it would void warranties etc. Fastforward. Now it seems to be factory fill in a variety of engines. Corvettes are a well known example for factory fills. I've even seen it as factory fill for premium commercial lawn care equipment. Since some synths like M1 are 'in' with the manufacturers - could that be part of the 'deal'. It simplifies things for consumers and reduces potential liability by having consumers simply change the oil per a schedule and not have the confusion of different schedules for oil changes based on synth or dino? I know - just a bit of the conspiracy theory but - just a thought - I could be wrong.