This used to be the “darling” oil for turbo Subarus of your vintage, so why not the EZ30? but back then, this was a dual-rated gas-diesel oil. Later on, Shell (Rotella) dropped the gasoline ratings, and I assumed it was no longer a darling for our boxers. Well, nothing in your UOA backs up my concern. Still, I don’t know what was “removed” to lose the gas ratings. But what do I know, I still use Castrol 0w-30 SL Euro, which works very well in my EJ25x turbo, and that is a somewhat-diesel oil without any API diesel ratings (though good ACEA ratings). It’s a bit thinner than your Rotella T6 40 and I’ve never run it much over 5k miles, but it stays thick enough throughout. I’ve dropped out of the loop recently, but goofy LakeSpeed oil geek recently ran a YouTube advising against diesel oils in gas engines, and the Rotella was his diesel sample. (I don’t think he really touched on dual-rated oils). But neither your nor my engines are direct-injected, which might play into the concerns he had. What the hell does all this mean? Dunno, maybe we are both too old-school…for better or for worse.
