So when a oil manufacturer does TBN tests, who does those? How are we to compare one oil to another if TBN numbers are off so much from test to test? Old method, new method, WTF is that all about? I thought TBN was TBN was TBN.

For instance, if I wanted to compare the TBN of my favorite oil (we all know what that is) to another oil that is not my favorite that begins with the letter A, how do I know that they used the same testing procedures? Should I just get a VOA?

 

Good post Rusty.
The reference in a seperate thread really created some curiosity on my part.
Like you, I had thought TBN was TBN. Maybe we will learn something here....

 

Roger that, Brian. Remember the UOA I had Blackstone do on my Chevron 10w30? The TBN came back 1.0. I wonder how that compares to the TBN scale that the oil companies use for their VOA's. If the Chevron 10w30 VOA TBN was an 8.0, with the "old" method, I wonder what that would be with the "new" method?

 

I'll attempt .

When new oil is checked ASTM D 2896 is used . Used oil is usually checked using ASTM 4739 although some labs check used oil with the 2896 in which always shows about 1.5-2.0 lower than 4739 . Why do some labs check used oil with 2896 I don't know .

If your speaking of Blackstone , well they invented their own way a short time back so I read . I don't like that way but it is repeatable and as long as you stay with their service you can reasonably compare samples other than their way will show a bit lower than 4739 .

Exxon/Mobil and a few others have their own test labs . Some companies use ANA .

Now here is my deal and might be written choppy, take it FWIW as I'm no expert but

TBN costs 2 bucks extra at the two labs I use . I get it for kicks but TBN is really only for new oil and typical analysis AND for Diesel engines and used oil .I was an oil hobbiest long before the internet and sales pitches and a gas motor does not care if it has alkiline reserve capacity at zero as long as the motor is started and ran near everyday . " geeze I'm a no typer but will keep trying ". Now that does not mean you can run an oil forever it's just that all these oils available today for the gas motors will still have TBN reserve after the oil should have been drained because of miles accumulated. Some will tell you a visual look at oil means nothing , I beg to differ if a guy has some mechanical background or just been an oil changer a couple dozen years

We live in a different world today where we have quick lubes that run the cars in and out . No old time mechanics to go over the motor when it's serviced like the old days . No common sense when coolant level is down , oil looks thick and milky yet many on the net are proponents on costly analysis to safegard and check for internal coolant leaks when in fact if the coolant level is constanly down a simple coolant system pressure check will tell much .

Analysis certainly adds to the cost of ownership and I buy 10 buck kits from ANA since I just do it for fun and my own personal use . They are about as good of a lab as any ----- Conoco Phillips uses them

 

Chris,
Thanks for the info.
I have been using Oil Analysis Labs in Spokane since I started getting UOA.
I'll reference my data sheet from them, or contact them, and see if I can determine which ASTM method they use.
Also, I want to check into 4739 and 2896 and see if I can learn more about them.
My last UOA showed my Chevron 10W30 with TBN of 5.8 after ~5,000 miles.
So now I wonder was it 5.8, or somewhere around 4? Either way, both are OK, but it would be nice to know.
Really, none of this matters a whole lot in a practical sense: I buy Chevron or Havoline oil and a Motorcraft filter and change every 4800-5000 miles.
But, it is interesting to me.