I have enough for 3 OCI's in the Outlander (15) That should make a year and a half! By then I will probasbly be itching to try something else or roll it into true extended intervals. I just think of it as Durablend "heavy". But I like the add pack most of all.
I have slight reservations about the seal conditioners.. but I don't think 3 OCI's will cause permanent harm.