What's a TBN test from Blackstone?

[jmacmaster]

I'm pretty new to this site. I just ordered a test kit from Blackstone Labs. I read the "Gas/Diesel Sampling Procedures" subpage on their website. It says: "Do you want a TBN? This is a test used to measure the amount of active additive left in the oil. It may be useful if you are interested in extending your oil usage. The test costs an extra $10." Can you guys elaborate on these statements? It sounds like they're saying that if I want to go a long time between oil changes a TBN will help me decide if I can get away with it. But isn't that something that the $20 test will tell me? That is, whether I ran the oil too long and its no longer effective -- or I could have run the oil longer and it would still have been effective?

 

[blupupher]

Did you read the page on TBN? Basicaly, the TBN lets you know how much acid fighting power is left in the oil. The basic test will tell you how well the oil has worked, not how much longer it could be used for.

 

[The Critic]

Correct. TBN shows the amount of detergency remaining in the oil, and can reflect on any stress that has been caused to the oil by dirt, chemical ingestion, fuel dilution, anti-freeze, etc. Mike