Diesel Piston Ring and Liner Wear - Compare Oils

[Pontual]

Originally Posted By: Shannow
Other bad stuff happens, like acid formation, dilution, soot loading that must be gotten rid of.

The Paradise garage sampling study showed that even taking out and replenishing a blackstone bottle's worth every 1,000 miles, the oil reaches an equilibrium.

Maybe taking half a sump out every 3,000 miles, and doing a perpetual OCI filters every 15-20 is the most technically correct way of running.

I'm still researching.


I'd suggest to save your used oil, decantle it and reuse. The settling would make the insolubles (including soot, some harmful acidic byproducts from oxidation like betumen material having water afinity, excess metalization and dissolved varnish) to separate from suspension and deposit at the bottom of the container. Since half sump would keep much fine dirt in sump.

 

[Pontual]

Originally Posted By: Pontual
Originally Posted By: Shannow
Other bad stuff happens, like acid formation, dilution, soot loading that must be gotten rid of.

The Paradise garage sampling study showed that even taking out and replenishing a blackstone bottle's worth every 1,000 miles, the oil reaches an equilibrium.

Maybe taking half a sump out every 3,000 miles, and doing a perpetual OCI filters every 15-20 is the most technically correct way of running.

I'm still researching.


I'd suggest to save your used oil, decantle it and reuse. The settling would make the insolubles (including soot, some harmful acidic byproducts and dissolved varnish) to separate from suspension and deposit at the bottom of the container. Since half sump would keep much fine dirt in sump. As in mobile2

 

[Ducked]

Originally Posted By: andyd
Why aren't we driving around on used oil?


I am.

Why aren't you?

I guess you must have a classic Morgan with a total loss oiling system?

 

[Shannow]

Ducked,
yep...it's "used oil" a LOT longer than it's "new oil".

 

[Ducked]

Originally Posted By: Shannow
Ducked,
yep...it's "used oil" a LOT longer than it's "new oil".


Wonder if there are general implications for testing relevance/validity.

I'd guess most testing uses (or at least starts) with clean oil, whereas oil in actual service is, on average, say 2000 miles old?

 

[BrocLuno]

I'd sure be more inclined to add back a quart of used oil to my fresh partial fill if it was as clean as the by-pass filters often make it

The trouble is that I can't get a by-pass filter into the engine bay of the Saab. It's just to crowded. The Bronco - no sweat

Now to find a good used Frantz assembly ...

 

[paulri]

Looking at the results again, comparing the new and used oil, the used oil had 2-3 times less wear and weight loss.

Is this a good idea of how much less wear any driver can expect, while extending an OCI? Or would the difference be much less in the real world? I realize this is just one sample, so I'm asking to see how reproducible these results would be. Earlier, some posters indicated that a real world use would provide a different ratio between mineral oil and new oil, so I'm wondering if the same would hold true for a comparison between new and used oil.

 

[Koz1]

Would a After treatment fix this. After total mixing heat treating the oil before final packaging?
You could do it with pressure to account for the actual in use forces?

 

[Ducked]

Originally Posted By: paulri
Earlier, some posters indicated that a real world use would provide a different ratio between mineral oil and new oil,


If they did, I think you could safely ignore them, since that isn't a meaningful comparison.

 

[Shannow]

Originally Posted By: Koz1
Would a After treatment fix this. After total mixing heat treating the oil before final packaging?
You could do it with pressure to account for the actual in use forces?


I've though that before, would probably nned frictional surfaces...cost and expense for not much gain maybe.

Or add a lot of different AW additives that activate differently..again, complexity and expense.

 

[paulri]

Originally Posted By: Ducked
Originally Posted By: paulri
Earlier, some posters indicated that a real world use would provide a different ratio between mineral oil and new oil,


If they did, I think you could safely ignore them, since that isn't a meaningful comparison.


Care to explain your comment?

Just to be clear, let me explain what I was talking about. Earlier posters in this thread were saying that in the real world, new oil would do much better relative to the mineral oil, than the new oil did in this test. I'm wondering if the 2-3 times less engine wear (as shown by used oil) would also be what drivers could expect in the real world, or if this also would change. Would the gap between used and new oil narrow at all, in engines in use in the real world? I suppose the only way I could tell would be to get a UOA with oils of various OCIs, but I thought I'd ask the question, anyways.

 

[Ducked]

Originally Posted By: paulri
Originally Posted By: Ducked
Originally Posted By: paulri
Earlier, some posters indicated that a real world use would provide a different ratio between mineral oil and new oil,


If they did, I think you could safely ignore them, since that isn't a meaningful comparison.


Care to explain your comment?

Just to be clear, let me explain what I was talking about. Earlier posters in this thread were saying that in the real world, new oil would do much better relative to the mineral oil, than the new oil did in this test. I'm wondering if the 2-3 times less engine wear (as shown by used oil) would also be what drivers could expect in the real world, or if this also would change. Would the gap between used and new oil narrow at all, in engines in use in the real world? I suppose the only way I could tell would be to get a UOA with oils of various OCIs, but I thought I'd ask the question, anyways.


I suppose I was being a bit picky, words-have-meaning stylee. Occupational hazard.

You wrote of a comparison between "mineral oil and new oil". That doesn't seem a meaningful comparison. Examples of meaningful comparisons might be between new and used mineral oil or new and used synthetic oil.

 

[paulri]

The reason why I used that comparison, was that this was actually part of the study. Earlier in this thread, there was a brief discussion of the study's results dealing with mineral oil, in which it did almost as good as new oil.

 

[edhackett]

Originally Posted By: Shannow
Ducked,
yep...it's "used oil" a LOT longer than it's "new oil".


I'm still leery of the applicability of tests that aren't done in actual running engines.

When it comes to the rings in an engine, excluding its first start, is the oil ever "new"? Given what you've found about residency times of oil in the rings, there is a supply of used oil present at the rings and time for the new oil entering the rings to become aged due to ample exposure to combustion byproducts and friction during that residency time.

Ed

 

[edhackett]

Originally Posted By: paulri
I don't doubt that used oil can perform very well. I recall articles linked to here, by teh SAE that said they outperform new oil up to 12,000 miles.

Its my understanding that these studies were for fleet vehicles, which would usually get a lot of freeway driving, wouldn't they?

Has anyone done a study from oil used in engines that did a lot of city, stop and go driving--comparing wear from used oil, to new oil?


SAE 2007-01-4133 tested to 15,000 miles and was a fleet of 3 Crown Victorias in Las Vegas. Although not stated, that would imply taxi service.

The oil was shown to still form low friction anti-wear layers at 15K. One must be careful of using the word "outperform" in this case. Yes, for formation of anti-wear layer vs new. No for being suitable for use in the engine. As Shannow stated earlier, there's more to it than that. By 5000 miles TAN was ~equal to TBN and the oils were showing oxidative thickening. All had oxidized out of grade and TAN>TBN by 7500 miles. By 15,000 miles one of these 5W-20 oils was an SAE 40 and the other two were SAE 50. All had TAN nearly three times TBN.

Ed

 

[paulri]

Originally Posted By: edhackett
Originally Posted By: paulri
I don't doubt that used oil can perform very well. I recall articles linked to here, by teh SAE that said they outperform new oil up to 12,000 miles.

Its my understanding that these studies were for fleet vehicles, which would usually get a lot of freeway driving, wouldn't they?

Has anyone done a study from oil used in engines that did a lot of city, stop and go driving--comparing wear from used oil, to new oil?


SAE 2007-01-4133 tested to 15,000 miles and was a fleet of 3 Crown Victorias in Las Vegas. Although not stated, that would imply taxi service.

The oil was shown to still form low friction anti-wear layers at 15K. One must be careful of using the word "outperform" in this case. Yes, for formation of anti-wear layer vs new. No for being suitable for use in the engine. As Shannow stated earlier, there's more to it than that. By 5000 miles TAN was ~equal to TBN and the oils were showing oxidative thickening. All had oxidized out of grade and TAN>TBN by 7500 miles. By 15,000 miles one of these 5W-20 oils was an SAE 40 and the other two were SAE 50. All had TAN nearly three times TBN.

Ed


Thanks. That was very informative.

 

[GMorg]

Wow, the discussion of this topic has changed a little in the last decade.

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/179319/1

 

[CT8]

Originally Posted By: Kuato
I won't pretend to have read the entirety or the math, but am I reading the chart on P215 correctly? It seem to show that cooler oil has a lower coefficient of friction, which to my unschooled brain says it's more slippery.

Plus it is nice to see research showing that older oil allows less wear. It's counterintuitive but we've speculated about it so much...

Thicker !!