The UOA says it did pretty well in my Z but I only ran it for two changes before the slight smoking on startup got annoying and it started burning off towards the end of my last OCI with it. I'm running M1 10w40 TDT right now and it seems to be doing pretty well so far. No smoking, maintains good oil pressure, and it doesn't seem to have used a drop. We'll have to see what UOA says about it after I change it next...