evidence AGAINST short oil change intervals

SUNRG

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Many moons ago, TwoSlick posted SAE study info (IRCC) that indicated that the initial wear (engine wear immediately after an oil change) is higher than the subsequent engine wear (wear that occurs once the new oil's anti-wear additives have established themselves). Since then, I've done extensive UOA testing in my TDI to begin to see if this "higher initial wear" theory is applicable to PD TDIs.

My results so far indicate that initial wear (0-2000miles) is higher than the engine wear in subsequent oil sampling intervals (2000-4000, 4000-6000, 4000-8000 (missed 6000mile OSI in second testing)).



Note: To exclude both inherited Fe wear metal particles and naturally occurring Fe in the oil (many oil VOAs will come back with Fe of 1 or 2) I did preliminary oil sampling at 94 miles on the first OCI and 228 miles on the second OCI - and only Fe wear after these respective data points was considered.
Oil: Elf Evolution CRV 0w-30 506.01
Oil Filter: OEM MANN
Fuel: B33 (33% ASTM Virgin Soy BioDiesel - 66% common diesel from a variety of stations)
Fuel Filter(s): MANN In-Line Pre-Filter, Stanadyne FM100 5-micron and 2-micron elements
Air Filter: OEM Type A (includes pre-filtration media)


Test Sequence#1: OSI / Fe Wear Rate
(note: this sequence ended prematurely when a rock took out my oil pan)
  • mile 94 to mile 2011 / 3.12 (higher initial)
  • mile 2011 to mile 4007 / 1.00 (lower subsequent)
  • mile 4007 to mile 6008 / 2.50 (lower subsequent)


Test Sequence#2: OSI / Fe Wear Rate
(note: this oil is still in my Golf PD-TDI and will be tested again at 10,000 miles)
  • mile 228 to mile 2016 / 2.79 (higher initial)
  • mile 2016 to mile 4319 / 0.00 (lower subsequent)
  • missed mile 6000 sampling
  • mile 4319 to mile 8108 / 1.84 (lower subsequent)


Based on these and other UOA results in this vehicle, the 50,000 mile oil change will likely be my last 10,000 OCI, since this data suggests that at least through 8,000 miles, draining good oil and replacing it with new oil results in more wear than just leaving the good oil in.

Important Note: Wear trends in your vehicle may be very different. I recommend using used oil analysis to determine the optimal OCI length for your TDI.
 

Dweebus

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Interesting, but if one is using the same type of oil for changes wouldn't the anti-wear additives already be established?
 

JamesBa

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You're using this oil:
Oil: Elf Evolution CRV 0w-30 506.01

Is this synthetic oil? If not, would the results of synthetic be any different?
 

SUNRG

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Dweebus wrote:
Interesting, but if one is using the same type of oil for changes wouldn't the anti-wear additives already be established?
I don't understand the oil chemistry details. Maybe one of the oil gurus could chime in with details. I just wanted to see if this higher initial wear theory / phenomena does occur in TDIs. It appears as though, at least with my TDI, using ELF 506.01 and ASTM B33 Biodiesel, that initial wear rates are higher than subsequent wear rates, and to answer...

mydeathbynapalm's question:
So you're going to what interval between changes???
I am switching to a 507.00 oil at my next oil change, I will repeat this experiment again (Test Sequence #3), and I'm thinking I will keep the oil in until a subsequent wear rate becomes the same or goes above the initial wear rate.

if it works it would be a completely new way of determining when to change your oil. even though it's somewhat unheard of (and possibly impractical) it makes sense - i mean why would you drain oil that's keeping wear down to 2.0 wear rate (for example) when you know changing the oil will result in a 3.5 wear rate?

i only say it may be impractical because you have to pull at least three samples during a single oil change interval to test this in your TDI.
 

Diesel Addict

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My guess is that the reason you're seeing higher wear initially is that after an oil change it takes a bit longer for the engine to build up the oil pressure and until then the engine is running dry, causing more wear.
 

mydeathbynapalm

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I guess that's the 'money' question...heh

FWIW... My friend almost lost a head due to a worn lifter...caught it in time. For 150000 miles he used Mobil 1 0w40 at 10000 OCI until, from what I could gather, the last 30000+ miles of that he was doing shorter (7500 and then 5000) OCI. Our trusted tech was looking at the evidence and said the oil wasn't holding it's own so to speak over those OCIs. Said tech uses Shell Rotella 5w40 and changes at 5k OCI I think... We're all modded out...though they more so than I at the moment...

Lots of heat introduced with these mods breaks the oil down faster...so less protection...needing shorter OCI? We all have ALH engines...

Not sure where I was going with that...I plan on an external oil cooler in the near future as more power mods are to be added as well. Maybe once all is said and done with my mods (for a time being) I'll do some samples to see what's going on.
 

cujet

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Nah, the higher wear metals are dislodged by the clean oil.

However I do agree that wear metals drop to near zero when oil changes are avoided altogether:) Just Kidding!

Interestingly enough, most engine failures occur due to overheating or other mechanical problems and are not due to oil related failures.

Quite often, a properly maintained vehicle will last an incredibly long time. That means changing all the fluids and repairing things before they break.

By the way, the wear metals we see are in such tiny amounts that the engine should last nearly forever.

Long life engines such as the typical 300K Chevy V8 engines typically have wear metals in the 100's of PPM throughout the life of the engine.

Chris
 

Tin Man

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cujet said:
Nah, the higher wear metals are dislodged by the clean oil.

However I do agree that wear metals drop to near zero when oil changes are avoided altogether:) Just Kidding!

Interestingly enough, most engine failures occur due to overheating or other mechanical problems and are not due to oil related failures.

Quite often, a properly maintained vehicle will last an incredibly long time. That means changing all the fluids and repairing things before they break.

By the way, the wear metals we see are in such tiny amounts that the engine should last nearly forever.

Long life engines such as the typical 300K Chevy V8 engines typically have wear metals in the 100's of PPM throughout the life of the engine.

Chris
Is it possible that increasing wear metals in oil as it is used over the drain interval and sits in the crankcase is just a normal accumulation that otherwise means the oil is the SAME in its lubricating properties over that interval or longer??? Just wondering.
 

SUNRG

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Diesel Addict said:
My guess is that the reason you're seeing higher wear initially is that after an oil change it takes a bit longer for the engine to build up the oil pressure and until then the engine is running dry, causing more wear.
it's impossible for your explanation to be true in my case because the very first sample was taken after 94 miles of driving in sequence #1 and 228 miles in sequence #2. what i'm referring to as the initial intervals are 94 to 2011 miles in sequence #1 and 228 to 2016 miles in sequence #2.

i did this to prevent inherited wear metals and naturally occurring Fe in the new oil from squewing the results - but it also eliminates your "dry start" theory as an explanation of the results. IMHO the early baseline oil analysis testing is what makes this study valuable.

cheers!
 

Tin Man

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SUNRG said:
it's impossible for your explanation to be true in my case because the very first sample was taken after 94 miles of driving in sequence #1 and 228 miles in sequence #2. what i'm referring to as the initial intervals are 94 to 2011 miles in sequence #1 and 228 to 2016 miles in sequence #2.

i did this to prevent inherited wear metals and naturally occurring Fe in the new oil from squewing the results - but it also eliminates your "dry start" theory as an explanation of the results. IMHO the early baseline oil analysis testing is what makes this study valuable.

cheers!
Unless you can specifically label the "old metal" wear indicators and differentiate them from the "new metal" wear indicators between oil changes, I don't know how you can come to the above conclusions. How can you say that the initial wear indicators are not just still stirred up from the oil change itself or the temporary disruption of additive protection?

It seems that the wear indicators are just "ballpark" numbers that only imply abnormal wear if they become very distorted or "going off the normal curve." The minute differences from 1,000 miles to the next can be explained by simple pooling of material with no additional extra wear. The oil can be full of wear indicators at higher levels near the end of its fill interval yet still be just as good, theoretically, as it was at the beginning. Other testing would need to show how well it holds up to really know, no?

TM
 

SUNRG

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let me explain the procedure better and hopefully this will clear up how this data can be viewed as supporting the "higher initial wear" theory. i should have done this from the start...
  1. oil and filter are changed
  2. car is driven 94 miles (using testing sequence #1 for this explanation) then a baseline oil sample is extracted and sent to the lab. the baseline analysis Fe content equaled 2 ppm. this Fe content is the sum of:
    1. Fe that is naturally occuring in Elf Evolution CRV 506.01. [VOA on this oil from the same lab indicated that the naturally occuring Fe in this oil equals 1ppm]
    2. Fe that was inherited from the previous oil. i both drain oil from the drain plug and extract oil using a vaccuum extractor for the most complete used oil removal that's reasonably possible.
    3. Fe caused by the first dry start after the oil has been changed
  3. car is driven to 2011 miles since the oil change (1917 miles since the baseline oil sampling), oil is sampled and sent to the lab, total oil Fe content is now 8ppm.
  4. to determine how much Fe wear occured during the first 1917 mile oil sample interval, 8ppm (Fe at 2011 miles) is subtracted from 2ppm (Fe at 94 miles) equalling 6ppm of wear during the initial 94 to 1917 mile oil sample interval.
  5. to determine the Fe wear rate for this first / initial oil sample interval (Fe ppm generated per 1000 miles), 6ppm is divided by 1.917 equalling an Fe wear rate of 3.129ppm / 1000 miles.
  6. then, the TDI is driven to 4007 miles since the oil change (1996 miles since the 2011 mile oil sampling), oil is sampled and sent to the lab, total oil Fe content is now 10ppm.
  7. to determine how much Fe wear occured during this 2011 to 4007 mile oil sample interval, 10ppm (Fe at 4007 miles) is subtracted from 8ppm (Fe at 2011 miles) equalling 2ppm of wear during the 2011 to 4007 mile subsequent oil sample interval.
  8. to determine the Fe wear rate during the 2011-4007 mile OSI, 2 ppm is divided by 1.996 equalling an Fe wear rate of 1.002ppm / 1000 miles.
this process is repeated for all subsequent oil sampling intervals so we can determine how much wear occurs and when it occurs. understanding when engine wear occurs is the essential goal of this process.

hope this clarifies things.

cheers!
 

Tin Man

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Thanks. Interesting to see when the iron ppm actually starts to go up in rate.
 

SUNRG

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Gothmolly said:
I had 115 ppm of Fe on 9500 miles of 505.01 VW oil. Maybe there's something in the Elf that works differently?
is this in your 2002 TDI? 115 ppm Fe in 9500 miles is high - but not unheard of.

what i recommend to people who have a TDI that to their knowledge is running perfectly BUT have an oil analysis come back with high Fe are:
  1. do a short "cleansing" OCI after your high Fe lab analysis. 5000 miles max.
  2. use Motul Engine Clean when changing your oil after this short OCI.
  3. both drain the old oil and Motul Engine Clean via the drain plug AND extract oil from the oil filter housing and oil cooler using an oil extractor (Pela 6000, Tempo Oil Boy, etc.)
  4. install a magnetic drain plug (ECS tuning - my #1 choice, MetalNerd - also an excellent option)
  5. install a new MANN/OEM oil filter. they are top quality and are designed to be used during up to 31,000 miles oil change intervals
  6. pour in a 507.00 spec oil. (currently only Elf Solaris LLX 5w-30 507.00 is available in the US, but Motul's 507.00 should be here shortly). 507.00 oils are tested to ensure an absolutely amazing level of anti-wear engine protection, the same outstanding level as 506.01 oils but at a 30% lower cost.
if after taking all of these measures, then driving for 10,000 miles and having the 507.00 lab analyzed, Fe is still elevated, some mechanical condition is contributing to this. it could be as simple as a performance mod(s) increasing engine power, stress and wear.

hope this helps!

cheers!
 

Turbosprezarka

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This is definitely interesting data. I still don't know if I actually believe though that fresh oil takes a few thousand miles to "situate" the anti-wear components of the oil. Or in other words that it takes a few thousand miles to break in the oil.

It seems to me that it is more that the oil is mixing with any contaminants/residue left over from last oil change that is still in the engine, absorbing it all for a few thousand, while wear remains constant until the oil eventually has too much absorbed in it and wear increases due to excessive contamination which eventually prohibits adequate lubrication. Or some other factor along these lines not associated with actual initial greater engine wear.

This test is good, it shows changes in the amount of wear metals at different OCI, but it doesn't determine the cause or the source of change in amount of wear metals. So the title "Evidence Against Short OCI" isn't really evidence against - yet.

What exactly does the SAE data say? Or other data put out by reputable organizations? I am green to such data. My theory could be wrong too, but does anyone agree that higher initial engine wear on oil sounds a little "off"?
 

AlaskaRanger

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You have created an interesting set of data. I am absolutely green with respect to the practice of oil analyses, so bear with me as I'd rather ask this here than create yet another thread:

1. What can those with experience in such analyses tell me about the associated error bars?

2. Has anyone here ever gone through the expense of sending multiple samples to multiple labs to satisfy your own curiosity regarding lab consistency, precision and, most of all, accuracy?

and

I was looking for and happy to find that you could provide the data for the virgin oil-component of Fe (1ppm). Now -

3. Does anyone know what introduced-ash from diesel combustion can contribute in the way of metals - Fe and others? How consistent might that be over time (a) from the same refinery (their own feedstock can vary from shipment to shipment) and (b) from different fuel sources?

I can envision situations in which a tester who does not control these factors can come to faulty conclusions regarding OCI.
 

TornadoRed

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SUNRG said:
[*]to determine how much Fe wear occured during the first 1917 mile oil sample interval, 8ppm (Fe at 2011 miles) is subtracted from 2ppm (Fe at 94 miles) equalling 6ppm of wear during the initial 94 to 1917 mile oil sample interval.... 6ppm is divided by 1.917 equalling an Fe wear rate of 3.129ppm / 1000 miles....

[*]to determine how much Fe wear occured during this 2011 to 4007 mile oil sample interval, 10ppm (Fe at 4007 miles) is subtracted from 8ppm (Fe at 2011 miles) equalling 2ppm of wear during the 2011 to 4007 mile subsequent oil sample interval.
[*]to determine the Fe wear rate during the 2011-4007 mile OSI, 2 ppm is divided by 1.996 equalling an Fe wear rate of 1.002ppm / 1000 miles.[/LIST]this process is repeated for all subsequent oil sampling intervals
My first contribution to this thread, and since I've ordered some Elf Evolution for my next oil change, I'll be watching closely as your tests continue into the 10k to 20k mile interval. I may do some UOA testing of my own.

I have to question the accuracy of the lab results, however, when you're trying to draw conclusions based on just a couple ppm difference between samples. Can the lab really state with certitude that the Fe at 94 miles was 2 ppm, and not 4 or 5 ppm? Or 8 ppm at 2011 miles, and not 6 or 10 ppm? Or 10 ppm at 4007 miles, and not 8 or 12 ppm?

My point is, these numbers are so small, that the margin of error could be nearly as great as the measured values. And if this is the case, then your thesis as stated in the top post:
My results so far indicate that initial wear (0-2000miles) is higher than the engine wear in subsequent oil sampling intervals...
will require a lot more data.

Two final points: (1) if your thesis is correct, do we know whether this phenomenon happens only with Elf Evolution? Or does it also happen with other motor oils, in other applications? And (2) even if it's correct, it doesn't seem like it will affect any decision-making; we really don't care what happens in the first 2k miles after an oil change, but what happens between 10k and 20k miles.
 

SUNRG

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TornadoRed said:
I have to question the accuracy of the lab results, however, when you're trying to draw conclusions based on just a couple ppm difference between samples. Can the lab really state with certitude that the Fe at 94 miles was 2 ppm, and not 4 or 5 ppm? Or 8 ppm at 2011 miles, and not 6 or 10 ppm? Or 10 ppm at 4007 miles, and not 8 or 12 ppm?
This is absolutely true. If experiment were performed once the data would be virtually meaningless. If the test sequence is repeated with similar results, we can begin to establish correlations...

My point is, these numbers are so small, that the margin of error could be nearly as great as the measured values. And if this is the case, then your thesis as stated in the top post: will require a lot more data.
Aabsolutely. This data correlates higher initial wear in two testing sequences. I understand that correlations are not proof and that the strength of a correlation is directly related to sample size. My current sample size is 2 (not strong) but before this we had no data. Now we have a little data and it does seemingly support the higher initial wear theory.

By the way, this is not my theory. I'm just beginning to test to see if it this theory / phenomena is applicable to PD TDIs.

Two final points: (1) if your thesis is correct, do we know whether this phenomenon happens only with Elf Evolution? Or does it also happen with other motor oils, in other applications?
The only way to determine if this theory is applicable to other oils is to test them. If many oils are tested, all with similar results, then possibly you could logically extend the theory to include other oils of the similar types to those that were tested.

And (2) even if it's correct, it doesn't seem like it will affect any decision-making; we really don't care what happens in the first 2k miles after an oil change, but what happens between 10k and 20k miles.
I personally am interested in how much wear occurs and specifically when it occurs during an OCI. To get the info you want you could test at 10k then again at 20k and compare. That would give you meaningful performance data for your vehicle and the oil being tested.

Cheers!
 

Tin Man

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Assuming there is data linking higher particle content to earlier engine failure. It is an intuitive conclusion, but one that would have had to be explicitly proven.

It may not be the particles themselves that are causing the wear. They may be a result of premature wear.

TM
 

Tin Man

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Has there been any new data of late?

Any more support for the theory of short/early oil change interval increase wear?

TM
 

wjdell

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Were in this initial data is the inherited count, seems it was excluded in this. Later SunRG does a initial count at 50 miles, IIRC, and shows that 6 ppm was inherited. A lowering of the numbers by ratio is depceptive. If I show 6 ppm inheritied over 1 k its 6 over 2k its 3 over 3k its 2 and so on when you want to show additive regeneration and you expect your data to be worth anything you must subtract the inherited first. No one has done two successful 20k OCI's. GMark has done the best with Delvac in a 20k OCI but the following went down hill slightly. SunRG did a 18k and at 16k it was impressive but by 18k the numbers had flipped. As in in the first 16k he had a count of 2 pmm and between 16k and 18k he had a count of almost 12 ppm. Thats about as much waer between 16 and 18k as he had in the first 14k.

http://forums.tdiclub.com/showthread.php?t=153676&highlight=507+12
 

DwightC

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SPIBUG said:
What size are the Fe particles?
What it is the clearance between the piston ring and the cylinder wall?
Regarding Fe particle size: The Oil Analysis Lab that we use (Mobil Laboratories) tells me that their spectrometer can only detect particles smaller than 15 micron. Therefore, the Fe you see on your test reports are for very small particles, that is, <15 micron. The bigger ones, >15 micron, don't even get counted so to speak due to spectometer limitations. Obviously, if you have lots of small particles, then it's logical to assume you have lots of large particles, too. THerefore, tracking the smaller particles (in ppm) is still a good "screening" method. For example if you get a jump from 10 ppm of Fe to 100 ppm, then you should resample the oil, do analysis lab test again and maybe do a particle counting to find out just what size particles are being created.

FWIW....The general theory of oil analysis describes the severity of oil condition as based on three main attributes:
particle size,
particle concentration and
particle type.

SIZE:
Most normal wear particles are less than 15 micron and commonly only 1-5 micron in size. Severe particles however, are often greater than 15 micron up to 100+ micron in size. Im talking about engines, here, not hydraulic systems.

CONCENTRATION:
To find out your particle concentration, I would typically use a particle count test. Most labs can do this. They categorize the number of particles in a 100 ml sample by particles in ranges of sizes, for example 1-5 micron, 2-10 micron, etc...(There is an ASTM for this, I can't recall the number right now...)

TYPE:
Lastly, for determining particle type, you need to visually inspect the particles under a microscope, (my lab scope is 100x, 500x or 800x) and determine their shape, magnetic characteristics and other particle attributes.

IIRC, (If I recall correctly), 1 micron (one millionth of a meter) equals 0.000039". Or they way I remember it, a 40 micron particle = 0.0015"

So piston ring clearances and cylinder wall clearances are a few thousandths (0.002 -0.010") as I recall - don't quote me on those numbers, tho. Aso, Ive heard that many standard oil filters are rated at about 40 microns. The really good filters are rated even lower. My point is that there is a relationship in designing oil filters and engine clearances. And Ive heard that 40 micron is a threshold value for oil filter suppliers or design. Personally, I want a lot lower micron value for my oil filter. I use Mobil 1 filters, but I cannot recall their rating....Ive used them for so many years now with good results. My point is this: Your oil filter should be filtering out 40+ micron particles. What passes thru your filter should be less than 40 microns and therefore, oil analysis is still good for testing engine oil but is limited to <15 microns due to spectrometer limitations.

One last thought. Repeatability in parts per million (ppm) is very difficult whenever you get really low ppm values, like 1, 2 or even 5 ppm. I guess I wouldn't pay a whole lot of attention to values that low until there is a standard deviation change or they get to 20, 50 or more ppm....At 100 ppm, Id be biting my nails if it were my car ....

FWIW, I do deal with oil issues daily at my work place and I hope that my basic explanation provides some common sense to analyzing your wear debris values shown in your lab reports.:)
 

DwightC

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FWIW, it is somewhat well known in the technical areas that I swim in, that after an oil change the wear debris values (fe and other elements) will typically return to their previous, pre-oil change values.

I really cannot explain this condition, but I know that it is expected and have seen it happen, many, many times.

I support a longer ODI (oil drain interval), not a shorter one because a shorter drain interval IMHO is a waste of time and money. On the other hand, changing oil a little too early is still better than changing it too late.

What Im practicing is using the VW recommended oil type (502/505) and an ODI of 10k. I'll check it every 20k miles with UOA (used oil analysis), just for fun...
 

SUNRG

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regarding more data to support the higher initial wear - i am no longer UOA testing in a way that would directly support this. my current fill of ELF Solaris LSX 50501 was baseline tested 28 miles after being installed and will not be tested again until there are roughly 6028 miles on the oil.

this thread pertains solely to a discussion of data that either supports or refutes whether or not engine wear is higher during the miles from 0-2000 than during the 2000-4000, 4000-6000.

wj brings up two additonal seperate topics:
  1. determining the upper mileage limit where an oil performs and protects optimally (i.e. - my extended OCI runs with 50601 and 50700 oils)
  2. determining the maximum OCI length that can be successively repeated while returning optimal performance and protection (i.e. - GMARK's attempt to run D1 for numerous, successive extended OCIs).
testing to determine if wear is higher initially after and oil change can be done by anyone willing to do a baseline UOA to discount inherited wear metals followed by 2k, 4k and 6k UOAs. and yes WJ, inherited wear metals were discounted in both examples referenced in post #1.

the only way to determine where the limits of the oils in both 1 & 2 above are is to push the oils past the points where they provide optimal performance and protection. ie - you have to be willing to subject your TDI to a OSI window of increased wear, but you can limit this by increasing the frequency of sampling as the oil approaches the projected maximum extended OCI mileage.

i hope this helps!
 

wjdell

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Ya what he said, and pertaining to post 25 that is why you should do a occassional DRF which is a particle count. Look at my UOA's and you will see I have and this will set off a alarm if you are gettting wear particles larger than 15 micron that might need further investigation. But you also can understand that if you are throwing large particles you will not have real low UOA's. A DRF was 29.00 and is all that is neccessary to see if you should perform more extensive test.
 

DwightC

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SUNRG said:
this thread pertains solely to a discussion of data that either supports or refutes whether or not engine wear is higher during the miles from 0-2000 than during the 2000-4000, 4000-6000.
And it is a very good thread. I took the time to provide some background on UOA and the factors influencing engine wear. Hopefully, I didn't derail the intent...

Im wondering if there is a complex (who knows, maybe a simple) explanation of engine wear during the interval between oil changes.

I think you all have provided some excellent insight....me for one, wants ta hear more! :)
 

SUNRG

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dwight - all the stuff you contributed is great. i really don't mind tangential stuff, i just don't want to confuse people. wj - brought up the two extended OCI topics and seemed to relate increased wear at the end of and OCI to this thread - increased wear at the start of an OCI. i just want folks to understand that they're three distinct topics - then we can enjoy discussing them all. thanks!
 
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