Hi, I'll tel you my experience as briefly as I can without any intention to create a firestorm, just what happened to me; after using one of the flagship oils from M1 the Porsche approved 5W50 for 18 years and 300K miles It got hard to find and learning what I could I found out I needed more ZDP than what I was getting from the latest formulation, I found Amsoil ACD had enough ZDP plus it is a long drain oil. After switching, the oil consumption went down more than 50% by the second oil change and the engine started to get cleaner, it was clean, M1 kept it clean but it is getting even cleaner, it did started to leak a little but after 4~5K miles started to re-seal itself. I have no affiliation with Amsoil and my supplier doesn't charge me but PC price since we have a distribution center so no shipping. Good Luck