Originally Posted By: dlundblad
Originally Posted By: Kuato
I got great UOA results at 5000 miles with VWB, Amsoil and ST Syn, all 5w30. Avoid M1 in this engine.
Drop the Lucas it is not helping anything, only thickening your oil without increasing additives. You are better off moving to a solid 40 grade oil, which the 4.0 loves; an example on here with stellar UOAs isRotella 5w40.
I recall reading you had great luck with ST syn in the past. Do you remember who blended the ST you ran?
It was Warren, I think...it was purchased in the Charlottesville VA area around 2008-2009. IIRC it could have gone a little further than 5k miles, but don't recall the TBN remaining. I no longer have the UOAs.