2010 FX4 | MS5K 5W-20 SN | 5.4L | 10,020mi

[Artem]

I'd call it a day after 10k on this oil and your driving style. 1.4 TBN leaves some buffer room, in the event your driving conditions change.

IMO, going longer wouldn't do you (or your engine any good). You'd just be doing it to prove that it can be done. We all know that you could possibly go longer without any issues but why push it? I think you'd pushed it long enough.

 

[dnewton3]

Why push it? Because there is clearly life left.

If he had run a UOA at 5k miles, some folks would say to "be safe" and OCI at 3k miles, because it's "cheap insurance".
If he had run a UOA at 7.5k miles, some folks would say to OCI at 5k miles, because he's got "safety margin" at the shorter OCI.
When he runs 10k miles on the OCI, and there is life left, why should he ignore the data he paid for? Because "why push it?", right?

And I call into question how you prescribe this statement:
Originally Posted By: Artem
going longer wouldn't do you (or your engine any good)

SAE study data, and UOA macro data, shows that wear rates continue to DROP out towards 15k miles. How is that "not good" for an engine? Extending the OCI out is good for his wallet, and his engine.

Extending the OCI should NOT be done blindly; but he's not blind. This isn't a sinle UOA; this is one in a long series that shows the engine is in fine health. There is excellent contanmination control, and very low wear rates. The TBN has dropped, as do all lubes, but the TAN is very much in control and not at a condemnation point. I never encourage extended OCIs on a whim, but this isn't whimsical; it's methodical. Short of yanking the engine out and doing a full-blown teardown, just what more could you possibly want?

Other than your gut feeling, just what is it that points towards a manadatory OCI at 10k miles? Please be specific and describe in detail the tell-tale signs you see that show imminent demise of the engine. If he had posted these UOA results, all in series, but never put an OCI mileage on them, just what would be your first clue that this fluid has been over-run? In fact, if he had posted the results, and not put the mileage or lube brand in there, just what would you point to? Don't forget; this Mobil dino lube is doing EVERYTHING that the expensive PU was doing, for far less cost!

Originally Posted By: Artem
You'd just be doing it to prove that it can be done.

Yes - that's exactly right. That's why Henry pushed the low-cost high-volume model T; it's why Bell called out to Watson; it's why Neil walked on the moon. Sure, those are extreme examples and 2010_FX4's little garage experiment isn't world changing; I get that. But your comment seems to be predicated on mediocrity and waste being desirable.

Why do UOAs at all, if all one is going to do it pick an arbitrary OCI from ones posterior? Why pay for knowledge and then ignore it? Why let the data talk, and then not listen to it?

He's not so much "pushing" the fluid as much as most other folks are wasting it. He's using a dedicated, thoughtful, consistent, analytical approach where most folks simply wing it ...

 

[Jim Allen]

Originally Posted By: dnewton3

Extending the OCI should NOT be done blindly; but he's not blind. This isn't a sinle UOA; this is one in a long series that shows the engine is in fine health. There is excellent contanmination control, and very low wear rates. The TBN has dropped, as do all lubes, but the TAN is very much in control and not at a condemnation point. I never encourage extended OCIs on a whim, but this isn't whimsical; it's methodical. Short of yanking the engine out and doing a full-blown teardown, just what more could you possibly want?



Great post, especially what I quoted above.

I would add; Since when isn't "great" good enough?

 

[Artem]

Originally Posted By: dnewton3
Why push it? Because there is clearly life left.

what would be your first clue that this fluid has been over-run?


I never once said that the oil has been over-run @ this point after 10k miles. I simply stated that with a TBN reaching 1.0 on Blackstone's scale, that it is nearing the end of it's useful life. Sure he could stretch it 500 miles, maybe a thousand but THAT would be pushing it, IN MY OPINION. The OP is more then welcome to do whatever he wants at the end of the day, I'm simply stating MY OPINION.

He even said so himself that he thinks the oil is just about done soon...

Originally Posted By: 2010_FX4
The question comes at this point--do I push a bit further or call it a day? I have not yet decided, but a 1.4 TBN is likely right at the limit and my driving pattern has changed somewhat, so the oil has more sump time, Decisions, decisions...


My recent UOA of Valvoline NextGen showed a TBN of 1.7 after 5k miles. The previous run with the same oil showed a TBN of 2.7 after 5k miles. Taking these fluctuations into account, the OPs next run could have a TBN below 1 or it could jump up a bit. Since he's now taking longer to accumulate the miles (just as I am) then I'd imagine the TBN isn't going to hold up as well as his previous 1-2 month OCI runs.

 

[dnewton3]

The TBN is 1.4, but the TAN is only 3.0. In fact, the TAN over the last three OCIs is staying low, even as the mileage is increasing! There is no exact linearity to TBN or TAN; they have wide variance and can be expected to shift with general (but not specific) sympathy of the OCI duration.

While Blackstone has a limit of 1.0 for TBN, they recommend an upper limit of 8-10 for TAN. He is no where near that condemnation limit for TAN; never has been. So both the TBN and TAN are fine.

Further, low TBN by itself is not a reason to condemn; this is already fully discussed in this thread. So is the TAN topic. These are cautionary markers that can lead to a decision to OCI, when combined with other issues. WEAR RATES and WEAR TOTALs are what matter most, along with low contamination. There is NOTHING here in this UOA to indicate that wear is bad (in fact, as expected, it's getting "better") and contamination is well in control.

TBN and TAN must be taken into context with the totality of the circumstances, not used a some end-all-be-all line in the sand. If TBN were .4 and TAN were 12.4, then I'd say he'd crossed a line. But neither value has been anywhere close to real problem areas. And neither is effecting wear at all! TBN tends to stabilize low; TAN takes a long time to escalate. It's response curve will go parabolic further out, but he's no where close yet.

This has already been discussed, but it bears repeating. There are some that would say that when TBN and TAN crossover, one should OCI. But clearly that has happened two times here and once nearly (within one-tenth), and yet wear rates continue to improve, as predicted by macro-data analysis. Acid build up does not pull off "chunks" of metal, it eats away at metals in a micro-view. Acids act on metals in a manner that very small particles (perhaps 2um all the way down to sub-micron) are emitted; these would easily show up in a UOA. Horrid desctructive phycial catastrophes work from the top down; they shed huge particles that often are too large to be seen in a UOA. But chemistry reactions are seen from the bottom up; they are often easily seen in a UOA. Since the wear metals are WELL in control here, and rates continue to drop, there is ZERO reason to think that TBN/TAN relationship here is anything but acceptable. Acid may have crossed over base, but it's clearly evident that has not happend to a level where the engine cares. And it's likely a fairly distant issue, as the variance in the last three UOAs show that TBN/TAN can fluctuate moderately, and yet wear continues downward!

Your "opinion" was that going longer would not do him or his engine any good. The facts (being his personal UOA data streams, SAE studies, and macro-market UOA analysis) all point to a conclusion otherwise. His engine and wallet can benefit from a longer OCI. You are most certainly entitled to your opinion, as is everyone here. But I'm asking that we lay emotion aside, and stick to facts. Taking all relevant data into account (his UOAs, SAE studies, macro-UOA data), and looking at the overall picture and not singular points, I'll ask this again: Why condem at 10k miles?


The concept to glean is one the relationship of inputs and outputs.

TBN and TAN are inputs to decions; they are not finite condemnation points. They are markers to indicate caution, and nothing more. As long as one is taking a full-view approach to UOA analysis (and 2010_FX4 is by far better than most BITOGers), using all tools and data from personal and mass-market experience, these criteria are not a reason to OCI; they are a reason to monitor more closely as one preceeds forward. In this UOA series, the TBN/TAN are not indicating anything other than continued monitoring is required; an OCI is NOT indicated.

 

[ron17571]

I would rather just spend ten bucks more and get the synthetic oil.
I average two oil changes a year. So your thinking would save me?
Twenty bucks or maybe a little more.
I did get that i change my oil to early,I could go longer. I think about all the cold starts in the winter and driving in Phoenix in the summer and want fresh oil.The best i can get.
Twenty bucks is almost nothing. I'm not sure what your trying to prove.Or why. If your car is an oil burner/leaker.I would go with cheaper oil.

 

[CarbonSteel]

Originally Posted By: ron17571
I would rather just spend ten bucks more and get the synthetic oil.
I average two oil changes a year. So your thinking would save me?
Twenty bucks or maybe a little more.
I did get that i change my oil to early,I could go longer. I think about all the cold starts in the winter and driving in Phoenix in the summer and want fresh oil.The best i can get.
Twenty bucks is almost nothing. I'm not sure what your trying to prove.Or why. If your car is an oil burner/leaker.I would go with cheaper oil.

Read my other posts and you will figure it out. The synopsis is that most people do not use their oil long enough--be it conventional or synthetic.