Speaking of TBN

[tig1]

Originally Posted By: Artem
^I have to agree. I get a used oil analysis to see the condition of the oil after x amount of miles, not necessarily wear numbers.

So who wants to run a low starting TBN oil down to zero and see what happens?

Has anyone seen a used oil analysis go down to 0?

 

[Doug Hillary]

Hi,
tig1 - In heavy high speed diesel engines the lowest TBN I've been at is 0.1 and the highest TAN was 9.1. These were during long OCIs and constant monitoring. No adverse results were found at tear down

 

[tig1]

Originally Posted By: Doug Hillary
Hi,
tig1 - In heavy high speed diesel engines the lowest TBN I've been at is 0.1 and the highest TAN was 9.1. These were during long OCIs and constant monitoring. No adverse results were found at tear down


Doug,
Thanks for the comments. Yours is the first post with actual experience of TBN being this low. I have wondered if we are making too big of an issue of low TBN numbers.

 

[Doug Hillary]

Hi,
tig1 - I believe that the accepted minimums of 1 (D4739) or 2 (D2896/ISO 3771) (or 1/3 of the VOA TBN) should be used in "non commercial-low use" applications

 

[Gene K]

I believe Doug Hillary used to use to run condemnation limits of 1.0 TBN and 8.5 TAN with Mobil Delvac 1 in his Truck Fleet?

Thats with engines that cost $40,000 to replace and have to last a minimum of 620,000 miles before resale.

This suggest to me that many of us run overly conservative limits but as to what those limits should be I think it really requires an intimate knowledge of both the specific lubricant and engine in question.

PS Doug somehow I dug up a post from 2003 or 2004 on TBN or TAN where you were referencing some results including that particular engine.

 

[Gene K]

Originally Posted By: Doug Hillary
Hi,
tig1 - I believe that the accepted minimums of 1 (D4739) or 2 (D2896/ISO 3771) (or 1/3 of the VOA TBN) should be used in "non commercial-low use" applications


Doug Ive seen a couple of US Fleets using 1.5 TBN (D4739) in Detroit S60 with conventional oils. In your experience is this reasonable? I thought I was playing it risky at 3.0 TBN. (Starting level of 10-11 TBN).