Sorry for the slow response but I’ve been distracted by non-car issues. I still use the recommended 0W-20 though it has been dealership serviced so who knows what they have put in it. What I can confirm is that I have not noticed any engine running issues and I have had no error codes. But to complicate matters the engine mounts are now so stiff that every vibration from the engine is clearly felt and you can feel as the engine warms up and becomes smoother. How much this has to do with the oil is impossible to separate from the engine mounting (The lower engine mount is the Airtec billet* one and the other two are Powerflex Black).
* I strongly recommend the Airtec (or the Whiteline which is very similar) as it’s appreciably better at maintaining grip than even the Powerflex Black. The negative, if you view it as such, is significantly increased transmitted vibration.
