Folks on here often say in order to clean up an engine they'll run a few short OCI's of like 3k before going to a regular OCI of say 5-7k. My question is if oil is still in good shape at 5-7k (or even at 10k), what benefit are you getting from a super short OCI like 3k? Would it be even better at 1k? If the additives, TBN, TAN, etc are all in the good range at 7k then I would think it's doing the same amount of cleaning at 7k as it would at 3k, 1k, etc. No? I'm wondering if we're just catering to our internal warm fuzzies when we think our oil is cleaning way better at an OCI half of what the oil is good for, or is this actually true?