Amsoil 10w40 with the fuel dilution was still in grade, double the TBN and a better additive package in my opinion. Granted the Amsoil was 900 miles less on the OCI, however my thought is to run the Amsoil again for the same length OCI as the HPL. I try to keep my OCI'S the same length so it can be relatively consistent following the performance in terms of staying in grade, TBN etc. The wear element is what it is but leaves a signature with respect to how well it stays in grade, remaining TBN etc.