Given the fact that Castrol is now the supplier to BMW, is it safe to assume that Castrol Edge EP 0w20 is the new Longlife 17 FE? After all it meets MB 229.71 specs. Anyone with insight about this? I don't have a sample of the new Castrol to send to Blackstone for comparison unfortunately, my older top-off oil is the Shell made 0w20 BMW TPT oil. Yes, I know it officially "doesn't meet the specs" but my guess it's probably the same oil. Thoughts, comments???