Originally Posted by drewvdw
To those that said there's only 1 T6 oil, you're wrong. There's the 5/40 and the 15/40...yeah, I accidentally ran 15/40 for a bit...and I have a busted motor, but I don't know how much that contributed, if at all.
I run diesel grade Rotella/Delo400/Delvac 15w40 in all four Subarus in the driveway with absolutely zero issues. It actually stopped oil consumption on my mother's 95 Legacy, and keeps my HLA motors nice and quiet. I highly doubt the 15w40 caused your busted motor.
Using 15w40 diesel grade oil was the best switch I made, and now will always be my choice.
And these guys are worried about diesel grade 5w40...