old oil better than new oil

Status
Not open for further replies.
Here's an idea to collect more data that I'd like to "throw" out there.
What if someone took a vehicle with a known history of UOA's (so data can be tracked). They run a quality dino for 3000 miles, and get another UOA. But the 3000 mile oil is drained and SAVED in a clean, sealed container. Then another run of dino for 3000 miles is done, more or less just as a "rinse", but a UOA is obtained from it just for comparison's sake (theoretically it should be close to the previous UOA results, and if it is, I'd asume the engine is pretty much in the same mechanical state). Then the 3000 mile SAVED oil from the beginning is put back in the engine, and run for 3000 MORE miles before another UOA is obtained. For even better accuracy/more data, a UOA could be done on the used oil prior to re-introducing it in the engine to ensure it wasn't contaminated during drain/storage. Then one could compare the 1st UOA of the test with the last, subtracting the wear metal levels in the first from the last to get real wear levels for the last run on the used oil. Then compare those "corrected" numbers to the original UOA to determine if wear went up or down.

I would be happy to do it in my '97 Maxima with 110,000 miles, but it would take a long time. I've just started an AutoRX cleaning, and have only put about 1500 miles on the car since the beginning of January.

I am of the change oil often camp, but am open to the idea of longer OCI's. I'm not saying either side is wrong, but I just can't understand how used oil can lubricate better. I would need a real world test like I described to start thinking otherwise.

If I was to assume that used oil gives less wear than new, I could only conclude that the additives in the new oil would account for the problem. Because oil doesn't wear out (according to AutoRX Frank and some others), but additives get depleted, I could see this as the cause.

Maybe I'm way off base. I'll leave this heavy thinking to the experts. In the meantime, I'll change my dino at 3000 mile intervals (severe service).

Dave
 
Re use of UOA: I think that the limitations of the method rules out UOA, except for establishing a trend on the same engine, and looking for failures of the coolant barriers etc. If accurate wear trends are required, the whole of the components need to be examined, including the filters and the sump, and measurements of wear metals established by the radio-nuclide methods as used by the oil and engine makers, on test bed regimes. Or by physical measurement and examination. All else seems to be quess work. Now, coming to the point, I'd stick my neck out and say OCI intervals for the service conditions, recommended by the engine maker, are the only firm basis on which to proceed in a rational manner. Evidence does not exist in the public domain for short OCI's, either positive or negative.
 
Dave H: as nortones2 pretty much said, typical UOA's are good for many things, but being accurate measures of engine wear is not one of them. They tell the concentration of metals that end up in the oil sample AND are within a certain size range. So the particles that are caught in the oil filter are left out and the particles in the oil sample that are too large are left out (upper limit if often 5 to 7 microns according to the link below).
Other than that, your test proposal sounds good and is refreshingly simple and reasonably effective. I think that your approach is do-able by us, but a better method of measuring wear is required. And it still won't account for the large particles that are caught by the oil filter but maybe someone has a method of accounting for those particles. The article below discusses what sounds like a good method of measuring ferritic wear metals (which I think is the most important wear metal). I'm sure someone else here can find a good method of measuring the other wear metals (copper, lead, etc.) http://www.predictusa.com/Lit/oilandwear.pdf#search='size range detectable UOA'
 
First of all, I do not buy the "cleaning" spike argument. If the spike were due to "cleaning" you would not get a spike with successive OCI's. You would only get the spike with the first 3k oci. Successive OCI's should not create a cleaning spike over and over. However, when you look at a large sample of UOA data, there is a clear trend that shorter OCI's have higher wear per mile. I am not doing a very good job explaining my logic, but I do not think the data supports a "cleaning" effect.

I like Dave H's experiment idea. It would definately not be conclusive, but would be interesting. As far as the particle size problem, I don't think it is an issue. Wear particles are small. Even if some are bigger than 7 micron, the amount of wear particles is probably proportional to the particles measured in a standard oil analysis.

I have a truck that I use for commuting. (I carpool). It is a 25 mi, mostly freeway commute, so the driving conditions are pretty constant. I drive about 900 miles a month. It currently has M7500 oil in it that I will run out to 7500 miles and sample. The problem is that it has about 160k miles on it and it burns a quart of oil every 2-3k miles. What would be good intervals for Dave's experiment. I believe in long intervals, so I would have no problem putting 3k or even 4k oil back in. I just wonder how the make-up oil would affect the experiment.
 
Winston,
If you are correct in the assertion that short OCI produce more wear per mile, over time, then no experiment needs to be done. The question is answered. Short OCIs appear to produce more wear than moderate OCIs. The exception would be if long OCIs actually hide wear because it is trapped in the filter for example. In this case, the UOA is not describing wear. Instead, it would be describing an equilbrium state with some other factor (like filter-age for example).

So, another approach would be to run 3000 miles on an oil, collecting samples every 1K, change the filter, and then run another 3000 miles again collecting samples every 1K. If the filter change causes a spike in wear metals, then we can blame better filtering for the absense of expected wear metals late in an OCI. If that is the case, then one may want to consider short OCIs with less frequent filter changes.

As for Dave's experiment, I am not sure what you will be measuring. At the second oil change, you drain oil with 3000 miles on it and replace it with oil with 3000 miles on. Is the effort really to examine the effect of physically draining and replacing the oil as opposed to putting different oil in the car? In theory, the oil that you drain at the second change is identical to the oil that you use to replace it. I am assuming that first change was not just after some sort of very-long OCI or other oil abuse.

Dave, can you explain exactly what question you will be asking?
 
It is the third oil change that will reveal the interesting data.


1. Change oil/filter. Drive 3k miles. Get UOA. Save oil.
2. Put in fresh oil/filter. Drive 3k miles. Get UOA.
3. Put in oil saved from step one with a fresh filter. Drive 3k miles. Get UOA.

The third UOA is the interesting one. 3k miles on "old" oil.

BTW I have an Excel spreadsheet with the data from 69 Ford "Modular" engine oil samples. I got it from another BITOGer. I had some fun playing with the data to determine trends. PM me and I will email the data to you. You research types might be able to find something interesting.
 
quote:
Originally posted by Winston:
1. Change oil/filter. Drive 3k miles. Get UOA. Save oil.
2. Put in fresh oil/filter. Drive 3k miles. Get UOA.
3. Put in oil saved from step one with a fresh filter. Drive 3k miles. Get UOA.
Click to expand...
One would have to insure the protocol here was sufficient to prevent contamination of the oil from Step 1. A UOA shortly after it's installation in Step 3 may be in order.
 
Ok, how is step three different from just changing the filter. You are replacing 3K oil with 3K oil and a filter. The only real difference is that the current design requires that you confound the data with oil storage. It appears to me that the only thing that is happening in step three is that you are replacing the filter and using "used and stored oil" as opposed to just "used." As far as I can tell, step three is not an oil change, it is really a filter change since the oils are theoretically identical.
 
The only thing that I see step 2 providing is that a UOA on the 2nd fill may show if any mechanical/dirt ingestion issues have sprung up since the beginning of the test. Sort of like a mid-test check to rule out anything that might throw off the results. You'd require that the 1st two UOAs to show nearly equal silicon/fuel dilution/UOA-detectable wear metals. Once that is cleared up the used 1st fill can be put back in the engine to go another 3k. The real comparison would be between a sample of the 1st fill that went 3k miles and a sample of this same fill that went 6k miles. But in my opinion as I said in my previous post, the comparison of wear cannot be done with a simple UOA.

But there are several ways to skin this cat. Each has their pros/cons.

Another method is to simply do two 3k runs one 6k run. Do tests that can actually quantify the true wear. Sum the wear values for the two 3k runs and compare to the one 6k run. But this method doesn't have the "mid-test check" that the Dave's does.
 
Umm.. Don't know what I was thinking. (obviously not thinking well). What I was thinking was... Oh nevermind. You are right. It is the same as a filter change. (with storage thrown in to possibly contaminate the oil)
 
I still think you can assign this a "seating" process designation by attempting to confound when the upramp occurs. It may not result in the desired effect ..but the failure would still yield data. If you did 1k UOAs after a short (one or two heat cycle) flush (to assure that any "action" of the new oil was too brief to impact too much - only to radically reduce residuals) ..and observed if and when any upramp occured. We'll take the article assertion that the upramp occurs between 2-3k. Let's say the result show this tendancy. You then do another short flush ...followed by a 1k OCI (which would not require UOA to be done other then FWIW). If the upramp event occurs between 1-2k in the next 3k OCI ..then it is a process that was interupted and would suggest that the action/upramp is a result of the oil's impact on existing metals/films in the engine. If it occurs at the same 2-3k mark ...then it would suggest that it is a process that is due to agents in the oil that are designed to sacrifice themselves in applying their own films.


That is, lets define the action as a neutralization ..as though a caustic/acid was in solution. If so, then we should see no change in the upramp of wear metals ..since the agent(s) will be present in the same quantities and still need to reach some reactive equalibrium. If, OTOH, this is a process like an ion exchange in a water softener ..then wouldn't we probably see the "attack" occur earlier (maybe later) in the subsequent OCI/UOA survey
dunno.gif



Anyone else see any validity to this view???
confused.gif
 
I think that we are spinning our wheels at this point. I have re-read the thread. I now have a short manifesto and would appreciate any evidence that it is wrong. Please, come kick my dogma.

I am of the oppinion that brand new oil is not yet at its best. I have a hunch that the spike in wear metals that is seen early in an OCI is related to TBN. Both the metals in question and TBN track together very well, but in opposite directions. Could be coincidental since they are both a function of time/miles.

For a modern oil, I think making sure that Si is low is much more important than OCI, base oil, or oil brand. I grant that there is a "too long". I think that the more important factors for too long is related to total soot, TBN, and accumulated Si or other contaminants.

Short OCIs, in general, likely produce more wear than moderate OCIs. The total amount of wear is likely measurable but irrelevant. In fact, lack of lubrication is rarely the reason our cars are "worn out"

So, what evidence is out there that I am wrong. Prove me wrong and I get to learn something today.
 
This same discussion has taken place at various times over the years on this board. I recall in an earlier discussion someone suggested that the higher wear numbers in a short OCI was due to the filter.The theory was that a new filter allows more contaminants through until it reaches a point where some of the pores are blocked and the filter becomes more efficient. The more efficient filter traps more debris which results in lower wear metals showing up farther into the OCI. I have no idea if this is possible, don't pretend to know. I also can't recall who originated this theory in order to give them credit. I just recall it and thought it might merit discussion.
 
quote:
I am of the oppinion that brand new oil is not yet at its best. I have a hunch that the spike in wear metals that is seen early in an OCI is related to TBN. Both the metals in question and TBN track together very well, but in opposite directions. Could be coincidental since they are both a function of time/miles.
Click to expand...
Well, whether or not anyone can disprove your assertion ..have you figured a modality for effecting the event to add weight to it? That is, if your suggested cause was true (which I find a comparable to my "base/acid" metaphor), would not you see this event at the same point regardless of how many short OCIs preceded the "test event". That is, flush/500/1000/1000/1000/1000/ and still get the upramp between 2-3k???

So far ..everyone appears to have opinions with various supporting theories ..but no one appears to really have a way to, if nothing else, disprove their, or anyone elses, suggestive causes (at least within our means).

FF: You can support or discount the filter being a factor by reusing the old one with the flushing action. It should purge residuals. If the event occurs at the same mileage ..then the filter isn't a factor. You back that up with the identical test(s) with new filters. Same data? Throw out the filter. Major alteration? Filter. Minor, but distinct change, contributing/mitigating factor.
 
Gary I wasn't referring to the proposed test idea. The idea as I recall it was an attempt to explain higher wear metals in short OCI's as opposed to lower rates in longer ones.The author seemed to believe that the level of wear particles remains relatively constant through out the life cyle of the oil but shows up more early in the cycle because more gets through the filter.Again I have no idea if this theory holds water.I just recall the theory.
 
quote:
Originally posted by Winston:
BTW I have an Excel spreadsheet with the data from 69 Ford "Modular" engine oil samples. I got it from another BITOGer.
Click to expand...
Too bad that data didn't include other variables so that one could do some complex modeling. The current data is of limited use, as even data transformations won't significantly reduce the heteroscedasticity of the residuals.
 
I think that all of the data needed to address the question likely exists. Over a large number of UOA, one should be able to observe if there "spike" in copper and iron for those people that do 1500-2000 mile OCIs. If there is, then the "new oil is just cleaning" hypothesis is likely incorrect. On the other hand, if the very short OCI crowd does not see the same spike in Fe and Cu, then the "clean effect" hypothesis is much stronger. A commercial group that does UOA probably already has a good handle on this question and they just aren't sharing. On the other hand, I would have expected some short OCI BITOGer to have the data and already thrown it into the discussion.

I think that the proplem may be that this group of oil changers may be the least likely to do a UOA. I suggest this because I think that part of the very short OCI "logic" is that they want to change the oil BEFORE it gets dirty. Why even do a UOA if the you are already convinced that the oil is still clean.

If one were to use an inexpensive oil and do three 1000-1500 mile OCIs and at each OCI the Fe and Cu fell, then I would definately begin to buy-in to the idea that the initial spike in wear metals is a cleaning effect. I would also suggest that such an experiment be done without disturbing the air filter/vacumn lines ect. Any introduction of abrasive Si would destroy the experiment. However, as discussed earlier in the thread, one would expect that an AutoRx treatment would effect this spike and the earlier conclusion is that is does not.

For the moment, I think that oil likely at its best when it has a couple of thousand miles on it. If that is the case, then very short OCI may produce more wear than moderate OCI. However, I acknowledge that in the life of a car, it really doesn't matter.
 
GMorg,
I see what you are saying about my proposed test, and agree you could run sample 2 to 6000 miles, with UOA at 3000 and 6000. This could give relevant data. I was trying to limit variables, but actually created the problem of drainage/storage (which was why I proposed a UOA again before the "old" oil from OCI 1 was re-installed). Some of the variables I was looking at was keeping filter changes constant, and NOT using make-up oil (as most likely would be necessary if running same dino to 6000 miles on a lot of vehicles). I think make-up oil and filters can be variables that we don't normally account for. We could do it your way, but I would propose filter changes and strictly limiting or recording make-up oil. And I understand that the third 3000 mile run (used oil) may require make-up oil depending on vehicle. That seems to be a variable with some vehicles. My vehicle uses no measurable (by dipstick) oil in 3000 miles, so would be a perfect candidate. However, it would take over a year for me to finish my AutoRX and then drive 9000 more miles. Anyone else have a vehicle that doesn't use measurable oil but puts on mileage quick? Not to mention willing to do the test?

As for the dirty filter theory, I can definitely see its plausibility. Dirty filters usually filter better (at the cost of flow) if not damaged. I don't know of a way to test how much, so I think new filters with every test will keep this "variable" in check.

Hopefully this helped clear things a little.

And the debate goes on....

Dave
 
Status
Not open for further replies.

Similar threads

A
Oil with best anti-wear for Chevy 3.6 timing chain protection?
2
Replies
36
Views
3K
JTK
Yuk
Are new oils always better?
Replies
10
Views
1K
Propflux01
C
Does engine oil need to break-in after an OCI?
Replies
18
Views
1K
Urshurak776
TiGeo
Should I push HPL longer than 4K OCIs with track use?
2
Replies
38
Views
2K
SammyChevelleTypeS3
G
Is this oil too old? Recs for a 2019 Subaru Outback, 2022 Lexus RX450h . . .
2
Replies
27
Views
4K
silversport
Back
Top