I have been plotting my TBN data with OCI and used the "0" data from Liquimoly's product data sheet (I'll get an analysis on virgin oil next oil change). Is this a reasonable to look at how long you can push your OCI? Blackstone is saying on my last UOA to go to 9K - I'd say looking at this graph that makes good sense. Finally, what TBN is the bottom threshold for "change it"? Thanks!