Mobil 1's TBN

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Nov 16, 2002
Did Trisynthetic always have a TBN of 12 like SS? If not, does this mean M1 reformulated SS with a higher TBN to handle extended drains better? Amsoil's website still shows Mobil 1 at 8 for TBN. This is misleading as almost every analysis has it at >12.
I seem to remember this question asked before and I believe that TBN of "8" was disinformation in the great oil wars [Smile]
I remember also, that it was not correct or might have been just an old batch. But does SS have a higher TBN then TriSy? [Smile] [ March 30, 2003, 05:13 PM: Message edited by: buster ]
That doesn't prove it's misleading. They reformulated it and the data sheets are the last items to get upgraded.
True, so I guess the old batches were lower at around 8 before SS came out. [Smile]
Since it's come up, I'm going to give you a sneak peek at a future "sidebar" I'll have online in a few weeks... TBN is difficult to test. The margin for error is typically plus or minus 10%. Therefore, for all practical purposes my first two analyses showed no change in TBN. I have a LOT more TBN info coming soon. [Smile] Cheers, 3MP
Originally posted by TooSlick: So the idea that Mobil 1, 5w-30 has a TBN of 15.5 is not reasonable at all.
So you're saying then that Blackstone screwed up the TBN test not once, but twice? I am skeptical of your skepticism. [Wink] The original bottle is gone but I'll see if they're willing to do a TBN test on another virgin sample, see what happens. Cheers, 3MP
3MP, Take a look at the VOA of the M1, 0w-40 done by Oil Analyzers shows a TBN of 10.1. The M1, 0w-30 formulation (using the same Ca/Mg additive chemistry) tested by Blackstone shows a TBN of 12.5. I think that Blackstone does a good job in terms of repeatability of their measurements, but their TBN values always come in significantly higher than other labs I've seen. Send a virgin sample of Mobil 1 off to Cleveland Tech Center or AVLube and you'll see what I mean.... The only oils I've seen with TBN's in the 15-16 range are HD, extended drain, European diesel oils, ie ACEA "E5" rated oils. This very high level of alkaline detergent additives is necessary to control high temp piston deposits in Scania/Volvo/Mercedes HD diesel engine designs .... A 15 TBN oil is going to have a sulphated ash level in the range of 1.8%-2.2%. That's the last thing you'd want in a spark ignition engine. The sulphated ash level of Mobil 1 is in the 0.8%-1.1% range - this is a good reflection of the level of organo-metallic detergent additives in the formulation. What happens when you change oil is that any remaining acidic residues from old oil within the engine are neutralized fairly quickly. So you tend to get an initial TBN drop in the first 1000 miles. Once this process is completed, the TBN will decrease at a slower rate.
The TBN of Mobil 1 will depend on which ASTM method is used. If you test it using ASTM D-2986, which Blackstone Labs uses, you will see a baseline TBN in the 12.0, +/- 1.0 range. If you test it using ASTM D-4739, which Cleveland Tech Center (CTC) and AVLube use, you will get a baseline TBN in the 10.0, +/- 1.0 range. In order to properly analyze TBN depletion, you need to use the correct starting point (and the same analysis lab). I should add that Mobil Delvac 1 (their HD synthetic diesel oil) is advertised as having a TBN of 12.0. Send a sample off to CTC and the TBN will come back within +/- 1.0 point to this value. So the idea that Mobil 1, 5w-30 has a TBN of 15.5 is not reasonable at all. You can also compare the levels of calcium/magnesium (the active detergent/dispersant additives) for Delvac 1 and Mobil 1 and see that the HD diesel oil has a more robust additive chemistry ....Delvac 1 has about the same level of Calcium, but it also has about 600 ppm of Magnesium. The new Mobil 1, SS formulation has almost no magnesium, maybe 50 ppm or so.
Um, ASTM D2986 is some kind of air filtration test?? [Confused] Edit: never mind, found it, the correct number is D2896. Sorry! [Cool] Cheers, 3MP [ April 03, 2003, 09:49 AM: Message edited by: 3 Mad Ponchos ]
Originally posted by 3 Mad Ponchos: Turns out Blackstone doesn't use D2896 at all. More to come in the morning. Cheers, 3MP
3MP, Did you determine which method Blackstone used?
Sorry, yes, I do have that info but the story is a bit more complicated than I initially thought. I plan on retrieving more ASTM data tomorrow afternoon so I'll try to remember to post more later this week. Cheers, 3MP
All right, sorry for the constant delays. Blackstone currently uses ASTM 5984. This has an official reproducibility of ~2 TBN units, though Blackstone says they can keep it within ~1 unit. Blackstone's margin is backed up by the blind test Les Carnes and I conducted last month. They are trying out a new machine that uses ASTM D4739, the same one used by many other labs, though they've reported disappointing results so far. This is not terribly surprising as the reproducibility for D4739 is a rather uninspiring ~21%. Not that any TBN test is very accurate, as even D2896 can only manage ~16%. Cheers, 3MP
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