I'm sorry, I meant TBN going down and the TAN going up.
Originally Posted By: DCRamsey
This is where I think Blackstone misses the boat. I subscribe to the theory that there is a crossover point where the trend line of the TBN going down intersects the trend line of the TBN going down. This is where the oil should be changed. I am always surprised when I read a report that suggests taking the TBN to 1. I have no dog in this fight, but why in the world would you run oil almost 10,000 mile in a brand new car, especially a turbo? It’s your car, so it’s your decision. I’ve started to believe that there is a point where extending drain intervals is a good idea taken too far. I’ve spent my share of money on UOA’s and I’ve come to the conclusion that, for me, it’s better to spend the money for the analysis on an oil change. Just a thought.