UOA vs. filter- distorted wear picture

[vinu_neuro]

Recently I came across some old threads by a poster who was doing 30k+ mile intervals on his S2000 and consistently (trend) ending up with ~10ppm iron using a bypass filter. That seemed unusually low and I can't help but see that filtration efficiency (at filtering, not flow) significantly skews UOA results. So to get a realistic picture of wear for a given oil versus another, you'd have to use the same filter. This recent thread is a great example. I'm grateful that he spent the money to have particle count analyzed and shared the results, and it shows how big a difference the filter can make. Even if one used minimum three samples, one oil can be shown in significantly better/worse light through UOA's just because of the filter. Or if one constantly changes filters, there may not be any real significance in a trend.

For absolute wear (same type of filter used continuously), could an engine could be consistently wearing significantly at the same level from the very first sample at say 80k miles and stay there (the evidence would be hidden in the filter)? Or would would wear accelerate if there was a problem and show up in the trend?

Maybe this seems obvious but I rarely, if ever, have seen this discussed. Just thought it's worth noting on our board with many users that constantly chasing the next best deal on oils and filters. This is a science, but it seems like many don't approach it that way.

 

[johnachak]

Just curious. If you add the expense of a bypass filter system, the extra costs of the filters and the oil analyses, wouldn't you be better just changing the oil and filter more often?

 

[Artem]

Originally Posted By: johnachak
Just curious. If you add the expense of a bypass filter system, the extra costs of the filters and the oil analyses, wouldn't you be better just changing the oil and filter more often?


Techinically, yea but it's a matter of principle that we do UOA and run oils for extended intervals. It's a hobby for some (myself included) and i love seeing how my engine is doing.

 

[vinu_neuro]

Originally Posted By: johnachak
Just curious. If you add the expense of a bypass filter system, the extra costs of the filters and the oil analyses, wouldn't you be better just changing the oil and filter more often?

Probably. I just used that example to illustrate the point of this thread. I think oil analysis and expensive filtration, etc really only become cost effective when you're dealing with fleets, so if you do UOA's a couple times to determine the appropriate intervals, the scale at which you save money off that can be enormous. The other scenario where UOA's might pay for themselves multiple fold is trending wear and spotting abnormal wear before it escalates into something big, in expensive equipment, eg. jet engines.

Back on topic please.

 

[Artem]

OP, i've done a few particle count tests using the same oil filters / oil and the numbers would sway 1-2 points from one report to the next. Even had a shorter interval show less wear metals yet a higher particle count vs a longer interval.

Here's an example:

Amsoil SSO was used for the current report and the previous 10,300 mile run. Same Amsoil oil filter for both runs.

Now tell me, why is the particle count higher with the shorter run?

 

[JOD]

Originally Posted By: johnachak
Just curious. If you add the expense of a bypass filter system, the extra costs of the filters and the oil analyses, wouldn't you be better just changing the oil and filter more often?


If cost is your only consideration, sure. There's little question thought that the bypass/prelube system mentioned in this thread offers lower wear than any other alternative, including changing your oil every 500 miles... You're not going to achieve that level of filtration without a bypass system (at least with the currently available filters). Changing your oil more frequently isn't going come close to achieving that sort of performance. And keep in mind that PPM per mile generally goes down, not up, as the OCI is extended (until, or course, the lubricant isn't suitable for use--then it can go up quickly).

Is it "worth it"? Well, he has a really expensive engine, drives a lot, and probably values engine performance, so in case his it probably is "worth it"; wear is incredibly low and his engine is probably performing better than when it was new. For many others, it's probably not worth it.

 

[Artem]

Good post JOD. I fully agree. i hate when people post the "why spend money on UOA, just change the oil more often" reply.

 

[vinu_neuro]

Originally Posted By: Artem
OP, i've done a few particle count tests using the same oil filters / oil and the numbers would sway 1-2 points from one report to the next. Even had a shorter interval show less wear metals yet a higher particle count vs a longer interval.

Here's an example:

Amsoil SSO was used for the current report and the previous 10,300 mile run. Same Amsoil oil filter for both runs.


You missed the point. The ISO particle count that user showed differences in filtering ability of different filters. The point to take away from his results is that changing filters can greatly influence UOA results.

If you want to discuss what's going on in your engine with particle counts vs. wear metals that's a separate issue, Particle Count is the measurement of all particles that have accumulated within a system, including those metallic and non-metallic, fibers, dirt, water, bacteria and any other kind of debris.

 

[d00df00d]

Originally Posted By: vinu_neuro
Recently I came across some old threads by a poster who was doing 30k+ mile intervals on his S2000 and consistently (trend) ending up with ~10ppm iron using a bypass filter. That seemed unusually low and I can't help but see that filtration efficiency (at filtering, not flow) significantly skews UOA results. So to get a realistic picture of wear for a given oil versus another, you'd have to use the same filter. This recent thread is a great example. I'm grateful that he spent the money to have particle count analyzed and shared the results, and it shows how big a difference the filter can make. Even if one used minimum three samples, one oil can be shown in significantly better/worse light through UOA's just because of the filter. Or if one constantly changes filters, there may not be any real significance in a trend.

Well said.


Originally Posted By: vinu_neuro
For absolute wear (same type of filter used continuously), could an engine could be consistently wearing significantly at the same level from the very first sample at say 80k miles and stay there (the evidence would be hidden in the filter)?

I'm not well informed enough to answer this question as I understand it. However, could you say more about what you mean in your second parenthesis? What evidence would be "hidden in the filter?"


Originally Posted By: vinu_neuro
Or would would wear accelerate if there was a problem and show up in the trend?

If wear accelerates, the UOA may or may not show a trend; if it does show a trend, the trend may be in the wrong direction (e.g. if the particle size profile shifts toward higher sizes, the increased wear may correspond with lower numbers on a UOA).


Originally Posted By: vinu_neuro
Maybe this seems obvious but I rarely, if ever, have seen this discussed. Just thought it's worth noting on our board with many users that constantly chasing the next best deal on oils and filters. This is a science, but it seems like many don't approach it that way.

Wouldn't be the first time, and won't be the last.

 

[vinu_neuro]

Originally Posted By: d00df00d
Well said.

I'm not well informed enough to answer this question as I understand it. However, could you say more about what you mean in your second parenthesis? What evidence would be "hidden in the filter?"

If wear accelerates, the UOA may or may not show a trend; if it does show a trend, the trend may be in the wrong direction (e.g. if the particle size profile shifts toward higher sizes, the increased wear may correspond with lower numbers on a UOA).

Wouldn't be the first time, and won't be the last.


If the filter is efficient, wear particles that would show up in a UOA with an inferior filter, would be trapped by this efficient one.

I only used the particle size count that user posted to illustrate how great of a difference there can be with different filters. I only have a guess for how particle size fits into trending.

 

[Artem]

Originally Posted By: vinu_neuro


You missed the point. The ISO particle count that user showed differences in filtering ability of different filters. The point to take away from his results is that changing filters can greatly influence UOA results.

If you want to discuss what's going on in your engine with particle counts vs. wear metals that's a separate issue, Particle Count is the measurement of all particles that have accumulated within a system, including those metallic and non-metallic, fibers, dirt, water, bacteria and any other kind of debris.


Oh... Lol. Yea i somehow missed that.

Carry on.

 

[johnachak]

[/quote]
Is it "worth it"? Well, he has a really expensive engine, drives a lot, and probably values engine performance, so in case his it probably is "worth it"; wear is incredibly low and his engine is probably performing better than when it was new. For many others, it's probably not worth it. [/quote]

Cost is not the only consideration. I guess since I only put < 5000 miles a year on my expensive engine I cannot quite grasp the concept. I just change my oil 2x a year. I guess If I had a fleet of commercial vehicles it would make sense. ( I have dispatched trucking companies in my life time). I guess the key was when you said he drives many miles. My situation causes a different set of maintenance problems. By the way, I value my engine performance a lot. I track my MPG's per fill. I constantly monitor for changes in oil pressure, temperature and speed V.S. rpm.

 

[Jim Allen]

The addition of extremely efficient filtration (bypass or otherwise) does skew wear metals in a UOA if you compare the new levels to the old. You could have said the same thing in the era when engines went from bypass only to full flow filtration. The same engine that once had only bypass filtration, when converted to full flow likely showed a big drop in wear metals. You measure wear metals at the level of filtration you currently have. If you make an improvement, you have to adjust to that improvement, right? I guess the only way to measure accurate wear in any engine that has any sort of filtration at all is to sample upstream of the filter.

In a practical sense, it seems to me you can either see a wear metal trend in a UOA OR have very efficient filtration. I see UOAs as useful for trending wear ONLY if you are religious and scientific (or pedantic) about it anyway. The occasional UOA is nearly useless in that regard because it only presents a snapshot of one moment in time that may or may not represent the totality of what's happening in that engine. I see spot or occasional UOAs as very useful for determining a OCIs. For tracking engine wear.... might as well break out the tea leaves.

In my mind, bypass filtration (or any form of filtration enhancement) is best thought of as an OCI extender rather than a engine life extender. It does extend engine life to a degree but you can achieve the same engine life with short intervals. Short intervals are a colossal waste of resources, however. I see bypass filtration as a way to drastically extend the OCI while maintaining a low level of wear.

The numbers may not crunch in all situations and make the addition of a bypass system cost effective. It does if you crank on lots of miles over short periods of time or keep you vehicles for decades. For the average North American, there probably isn't a payoff, except emotionally.

 

[INDYMAC]

I think the prelube pump installation is a more valuable investment along with a block heater (if you live up north) to increase engine life expectancy than a by-pass filter system. I don't have anything to back that up though.

 

[vinu_neuro]

https://bobistheoilguy.com/forums/threads/why-iron-ppm-numbers-are-not-good-wear-indicators.142162/

 

[cchase]

I don't have anything to add, just wanted to say that this is a great thread. Gives me faith about the forum.

 

[ltslimjim]

I agree with Jim Allen's points. Seeing how well an oil holds up(in an effort to extend OCIs) in any particular application is an aspect that reflects more on the vehicle and other factors more so than the oil itself vs another oil.

How well filtration; air and oil(from stock to pre-lube/bypass setups), perform to prevent the base oils from getting used up in suspending crud for long periods of time, for instance, is indeed critical for oil life let alone engine life it no oil changes were performed(enter sludge horror stories).

This also must be measured against the type of service a vehicle undergoes(all that implies), as these variables DO change and should be taken into consideration as well.

For instance, contaminants such as silicon(Si) in the form of abrasive dirt/dust or coolant/anti-freeze(Sodium/Potassium/Si...depending on the formulation) we know will increase wear in an engine, generally, and a UOA can help spot this.

Therefore, most try to find the BEST possible filtration; including sometimes going above and beyond with pre-lube/bypass systems on top of the stock app setup at times, in order to 'safely' extend OCIs, because of the higher liability poor filtration presents with an extended OCI, an oil getting 'used up'.

A typical 3,000-5,000 mile interval may get by with basic filtration efficiency, as the reliance on 'wash out' from the oil change drain/refill is a 'fail safe' and the 'clincher'. Where as, there is obviously not the draining and refill of fresh oil when going up to 10,000 miles or longer, and thus the 'clincher'(if mechanically sound and there isn't a 'considerable' amount of insols to suspend/filter out from the start) is the filtration.

This of course is aside from the initial hurdles of anyone considering extended OCIs; that of finding out if an app falls under normal/severe/extreme service, along with knowing how your application is 'generally' considered on it's potential for extended OCIs(hard or easy on oil to begin with?).

 

[ltslimjim]

So, perhaps to gauge how your engine is truly averaging, in the 'average' sense of the word, would one perhaps be best served just have a basic air and oil filter setup(non-extended performance) ran across a few oil changes(3 or more) of similar mileage, to establish the engine's trending first?

That would be with the same oil/filter(air included) combo(entry level) to establish what that particular engine/app is doing for itself vs. the 'universal average' department(if applicable), before attempting to 'see' what improved filtration (including above and beyond) would do to a UOA's numbers regards particle counts/insol tracking/oil cleanliness at the end of an OCI(let alone additive life)?

As the other poster(cant recall whom at this late hour) that performed particle counts with various oil filters showed is true or if it holds any weight, then the Royal Purple, Mobil 1, Amsoil(oil filters), etc. all performed markedly better(though perhaps no distinct winners, just perhaps 'better' overall for that particular app. It was still worth noting since it help made the price point more reasonable, especially in extended OCI apps, to go for a top-end filter.