Well auskip hasn't reported any oil consumption and he's supposedo be running M1.
I know my car, and I'm sure almost all the others burning oil, burns Subaru/Idemitsu 0w20. My car also burns Castrol Syntec/Edge 5w30.
At this point, I have to rule out weights/brands, and me and a couple others seem to burn whatever oil is in there.
If it weren't a "total loss" oiling system, I'd be running Amsoil, no question about it.