Yep I read that part because my dad has a CX-5 and he was asking the same thing. I'm still not convinced. If it is because of the additives then other direct injection gas engines should avoid using our high octane as well? CMIIW but the Subaru FA20 is DI but it requires premium fuel.
Mazda took great pains to convince people that their high compression gas engines don't need high-octane fuel to avoid knocking. Baka somewhere along the way it was interpreted from "not required" to "do not use".
But I'm still glad that I don't have to use expensive fuel
