Bypass Oil Filtration for Engine Longevity

[nullack]

Gday folks,

So I've been going through the archives and I would like to better understand the argument about how its claimed bypass filters prolong the life of the oil not the engine itself.

The premise of this argument is that crud not filtered by the oil filter is so small that it takes a long time for it to even reach a 5 micron size. Therefore if you drain your oil say every 5000klms then you wont have any crud large enough in micron size to do damage that the oil filter wont pickup.

This argument appears to me to be likely flawed because I dont see in practice how we can ensure that crud not filtered by the oil filter is smaller than one micron. I understand most filters wont do anything of consequence under around 30 microns. Theres a large gap between 29 microns and sub micron sizes.

I would be interested in any proper technical studies and the like to answer the question of if a bypass filter adds to engine life definitely.

Thanks folks.

 

[SteveSRT8]

The facts are that no regular oil filter can ever be really effective because it would plug up too quickly.

A bypass filter is an excellent way to keep an engine nearly forever. Some brands [censored] near put out oil cleaner than new!

I have used them for over 25 years on vehicles of ALL types.

 

[SWHeat]

Awaiting SteveS to chime in and state that bypass filters are a waste of time and that any engine will outlast the chassis, transmission, electrical system, etc. with proper OCI's.

Awaiting dnewton3 to give an in-depth cost analysis on why a bypass filter would only be good for extending OCI's and not for extending engine longevity.

Come on guys.

Oh, BTW, they are both probably right. But, I still like the idea of having the cleanest engine possible to hopefully get the bestest out of my engine for the longest, just because.

 

[Steve S]

The Bypass will give a cleaner oil but the oil that the engine sees is still the oil that is filtered through the full flow filter . The wear benefit is not as it would seem. Remember this first there were no filters then they put bypass filters on the engines these bypass filters were not the "sub micronic" type filters we think of . Then when full flow filters were designed in the the oil system engine life increased dramatically. The best would be a submicronic full flow filter then there may be an increase in engine life. Just because is a great reason I use it often but as far as a bypass filter on a passenger car what ever floats your boat I would guess. What benefit is having the cleanest engine when just clean enough will let your engine outlast the rest of the car

Made a good living looking at the insides of engines.

 

[nullack]

Generally in my country its the engine that goes first. Anyway, thats offtopic to the thread.

This thread is about the specific question of if a bypass filter extends modern engine life. It was suggested it does not and the argument as to why seems flawed to me so Im interested in understanding it further.

I understand that the sae did a study which suggested most engine wear is caused by crud 5 - 25 micron in size or similar. I also believe with common rail piezoeletric diesel engines some tolerances are closer than 5 microns too.

 

[nullack]

Im ready to conclude the "we dont need bypass oil filters because particulate sizes are under 1 micron or filtered by the full flow filter" argument as nonsense. This is disproven by used oil analysis data under the ISO cleanliness codes that looks at particulates at 4, 6 and 14 microns in size. Partcilautes in those sizes are there.

 

[Gary Allan]

It's an implied inverted argument that a bypass filter extends engine life. The economics of having it do so are not sensible for the potential additional mileage. The most practical use of them is to control particle accumulations so that condemnation levels are further apart in mileage. Since this presents challenges for most gasoline engines and, more importantly, the chassis that they reside in, they're not usually sensible from a cost:benefit standpoint. The junkyard will get a very clean engine.

I think that this economic road block may morph a bit in the coming years. I don't think that we'll be able to throw cars away like we do now.

 

[nullack]

Gary surely a lower particulate count in the oil means less wear when the engine is running that oil? Im not interested in the costs of the kit or ongoing filter costs - simply the question of increased engine life.

edit : not wanting to get off topic but my current vehicle is 23 years old. I intend to purchase a new one and keep it for decades.

 

[Jim Allen]

Originally Posted By: nullack
Gary surely a lower particulate count in the oil means less wear when the engine is running that oil? Im not interested in the costs of the kit or ongoing filter costs - simply the question of increased engine life.

edit : not wanting to get off topic but my current vehicle is 23 years old. I intend to purchase a new one and keep it for decades.


Won't speak for Gary but IMO, there are so many good full flow filters on the market now, that you can improve filtration radically over what your 23 year old car (or truck) had available. Your new car should last even longer without the added expense of a bypass system. Oils are better now too, and engines "soil the oil" much less than they used to as well. I agree with Gary that, yes, you are potentially extending the life of the engine but not in a way that you will likely ever be able to benefit from or amortize the costs of.

I am also driving a 23 year old vehicle (truck) that I bought nearly new. I put bypass filtration on it... but it's a diesel. Bypass filtration is more economically feasible on diesels because of the soot. I should be able to extend the OCI and save money, while extending the life of the engine (only 140K miles so far).

 

[dnewton3]

I'll chime in here; been a while since I've touted, so to speak.

I firmly believe that bypass filtration is benefitial; it helps extend your OCI, and that's can be a huge fiscal savings tool if you can keep your (joyfully) grimey hands off the wrenches.

However, there's a lot of sensible logic, and analitcal data that suggest bypass filtration does little to add "life" to a piece of equipment. Now that I've opened the can of worms, let me explain where my thoughts come from.

Many years ago (let's say 20+ for the sake of the argument), cars and their engines didn't really last that long. It was very easy to add life to the engine with a bypass filter, as the full flow filter wasn't that great at the time. Further, the engine build quality was nowhere as good as it is in the last ten years, and continues to get even better.

But now, build quality of the engine, and the materials selected, and the design, along with better full flow filtration, can easily make an engine last 250k miles if just OCI'd properly.

Consider that the damaging particles a UOA can see are all 5um and smaller; that's the approximate limit of spectral analysis in a UOA. Yet, we also know that most engine damage occurs in the 5-15um particle size range, most frequantly at start up. Now, while it's possible that particles can start off this large (they break off in a landslide, and throw chunks into the stream), this it NOT the most prolific of chances. It is MUCH more common to have a large quantity of smaller pieces floating around, than to have several big ones. UOAs cannot tell us the size of the particles, only the composition; we can assume they are smaller than 5um, because that's all it can see. But particle count analysis can tell us both the size and frequency, but NOT the composition. A conundrum, we have.

As far as soot and wear metals, it's far more likely that they start out small; for soot, it's even typical to be sub-micron in size upon birth. So, until those little particles co-join (agglomerate) and grow, there is little damage that they do. They have to get 5um or larger to do any real damage, and by then, you are loosing sight of them in the UOA. Anything that becomes too large with immediacy is likely going to end up in the full-flow filter asap; the risk is low that it would continue on. The real danger is those 5-15um particles on their constant journey.

Here's where pragmatic logic occurs. The "best" way to keep an engine (or any other lubed piece of equipment) healthy is to keep the lube system clean below the critical level that the equipment needs for a long healthy life. For an engine, that's typically below 5um. So, we can achieve this one of two ways.
1) super filter the lube with bypass filtration
2) change oil often, before the particles become to large.

Either will achieve the task. You either clean the oil, or replace the oil. It's just that simple.

There's a member here (ottomatic) that had a 6.9L IDI Ford Diesel that had 450k miles one it before it was stolen. He OCI'd every 4k miles with dino HDEO 30w. 450K miles!?!?! Gee - just how much longer would that engine have lasted with bypass filteration??????? Who really knows. You don't. I don't. My point is that he OCI'd often enough to keep the contaminants down below the critical level. In fact, in theory, you could never use a filter at all, and if you changed oil often, you'd still see very little wear. I wouldn't advise to do that; they cost of a bad incident could negate the savings very quickly.

There are other benefits that people would claim regarding bypass filtation, such as:
1) increased system capacity resulting in lower contamination percentages
2) increased system capacity resulting in cooler oil

Let's consider these claims; I would agree that both are true. But neither is UNIQUE to bypass filtration. I can add a larger pan and get more oil, resulting in cooler oil and a lower PPM concentration. I could add an oil cooler that would do the same. I could add an additional full-flow filter system and do the same. In fact, ANYTHING that adds capacity, adds these benefits. So how is that unique to bypass filtration? It's NOT!

Here are two examples of how frequent oil changes can result in longevity. Neither used fancy filters or oil; just fequent oil changes.
http://www.knfilters.com/news/news.aspx?ID=157
http://www.autoblog.com/2008/02/01/wisconsin-mans-91-silverado-set-to-hit-1-million-miles/
Both these guys just changed oil every 3k miles or so. So, you see, it is possible to get extreme life from a vehicle, without having extreme filtration.

The ONLY thing, repeat, the ONLY thing, that bypass filtration does in a unique manner is clean the oil "better" for "longer". That's it. Period. It does not make the equipment last longer.

So, if you change your lube often enough, you can negate all but one benefit; you cannot save money by changing oil frequently. That is where bypass filtration has a UNIQUE advantage; it prolongs the lifespan of the oil.

Bypass filtration is a fiscal savings tool for your wallet, not a fountain of youth for the engine.

Equipment lifespan is effected by proper maintenance routines, much more than super-duper products.

My belief is that bypass filtration does not add life to your engine; it extends the life of your lubricant.

 

[Jim Allen]

Well said Mr. Newton! I think you are generally right. If a detailed study were done I think they might find a bypass system marginally increases the life of an engine, all other things being equal, but do the cost vs reward number crunch.

I should amend my comments above to say that I wish to EXTEND the OCI without DETRACTING from the life of my engine.

 

[Gary Allan]

There's again, an implied inverted argument. It could simply be stated that a bypass filter makes it more economically feasible to extend engine life through cleaner oil.

450kmiles = 150 ocis
450kmiles = 25 w/bypass filtration
250kmiles = 25 w/0gypass filtration

Life added due to bypass filtration = 200kmiles @ 1/6 the cost of alternatives.

(the figures are merely pulled out of my behind)

So, there's a semantic truth that relies on the same assertion being true. What is surely true, as dnewton3 thoroughly explains, is that any gains with the 3k OCI example, if bypass filtration was run in tandem, would probably not be able to be measured due to the "shaving of the onion" improvement that could be attained.

 

[Steve S]

Gary, the cost of the bypass filter and the elements and the extra oil has to be added in . The biggest factor would be how many miles is is put on the vehicle, and the sump size. An over the road semi truck with 12 gallons of oil and driven 12,000 miles per month would benefit from the best filters etc. Where as a car driven 6,000 miles per year would probably never see a pay back in any way. But then again things change.

 

[dnewton3]

Exactly Steve.

I'm a big fan of synthetic fluids and bypass filtration, when used in an enviroment that make sense.

Short OCIs and/or short ownership do not lend themselves to the use of superior products. If one uses these, they should be used to their full extent to get the ROI.

Gary has a valid point, with the inverted argument. But I tend to look at this topic, as I said, as to what is unique with bypass filtration. Can bypass systems claim long equipment life being solely in it's court; is this exclusive to bypass filtration? No - therefore it is a shared benefit that can be acheived via other means (frequent OCIs). The only UNIQUE trait is that it can do it cheaper.

Hence, from my (not so subtle) viewpoint, it's a savings tool and not a longevity tool.

 

[Gary Allan]

Quote:
Gary, the cost of the bypass filter and the elements and the extra oil has to be added in .


Sure. So?

Quote:
The biggest factor would be how many miles is is put on the vehicle


Sure. So? Did my comparison indicate otherwise?

Quote:
and the sump size.


On what? Would a 3 gallon diesel not extend his OCI's longer too?

Quote:
An over the road semi truck with 12 gallons of oil and driven 12,000 miles per month would benefit from the best filters etc.


How about something with 3 or 4 gallons doing 12k/month? Are you saying the the concept isn't scaleable?

Quote:
Where as a car driven 6,000 miles per year would probably never see a pay back in any way.


A car doing 6k/year suffers more from inactivity than it does usage. However, something like that could manage a longer term payback with a tp filter.

My example was just to offer the inverted view that Dave gave us. In his assertion he stated that a 450k engine received 3k OCIs. This was the basis ..or at least suggest that this was the reason for it. The inverted view ..the congruency or "other shoe" is that this engines life would have been shorter without 3k OCI's. So, let's speculate how long it would last with bypass filtration extended OCI's ..without bypass filtration.

See where I'm going here? If you're going to view short OCI's as the reason for longevity ..then bypass capable lengths of drain intervals without the filtration has to mean a shorter live. As one giveth ..one taketh away ..so to speak.

So, with the offered givens, I'd say that there are two paths to getting long life out of an engine. One is frequent oil changes ..the other is bypass filtration.

There are conditions implied there than make either sensible. First, to accumulate 450k ..even on a 30 year old chassis, you're doing enough mileage to extend drains. Since a 30 year old chassis is not likely, cutting it to 15 years old (thoroughly believable) ..you're at 30k/year. That's 10 OCI's @ 3k.

If you understand what I'm saying, I'm not disputing anything.

 

[deeter16317]

One thought/application comes to mind...

The newer generation diesels (with EGR and DPFs) tend to be "hard" on oil, even with with only moderate OCIs (some as low as 5k as I have seen posted). This is one application that the actual life of the engine would probably be extended with a bypass, preventing the soot load from getting too great too quickly.

Not to mention those with highly modified diesels that create more soot load than a typical oil/filter could handle.

There are definitely applications that a short OCI would be impractical...a boat comes to mind.

 

[nullack]

Hi guys.

Firstly can we please stop diluting the thread topic by introducing other issues like economics. The thread is about by pass oil filters for engine longevity. If you want to discuss costs can you please do it in another thread thanks.

dnetwon3 thanks for your post

Originally Posted By: dnewton3
there's a lot of sensible logic, and analitcal data that suggest bypass filtration does little to add "life" to a piece of equipment.


Im interested in a genuine and objective look at the question in this thread. If you have analytical data would you please share it with me so I can better understand it.

Originally Posted By: dnewton3
Consider that the damaging particles a UOA can see are all 5um and smaller....It is MUCH more common to have a large quantity of smaller pieces floating around, than to have several big ones. UOAs cannot tell us the size of the particles, only the composition; we can assume they are smaller than 5um, because that's all it can see. But particle count analysis can tell us both the size and frequency, but NOT the composition


I understand the ISO particulate count groups UOA results into 4, 6 and 14 micron sizes. Also, we know that the SAE did a study where they showed most wear occurring around 5 - 25 microns or so from memory I dont have the paper offhand. Damaging particles are not all 5microns and less as you claim. Particulate counts can be grouped into different sizes contrary to your claim. It would be irrational to worry about sub micron particulates that we know doesn't cause most wear - we should only be concerned with identifying the size of particulates that do cause most wear and be focused on measuring those sizes.

I think also since the SAE study was done, that journal bearing clearances and dynamic demands have seen the start point of concern go down to 3 microns. I saw this on a tribology paper recommending 3 microns and above as being of concern I will try to dig up the reference for that.

Originally Posted By: dnewton3
2) change oil often, before the particles become to large.


This is a false assumption. Test data proves that when we look at ISO particulate counts for lubricant cleanliness we see 4 and 6 and 14 micron particulate. Including UOA with a 5000klm oil drain interval. It is untrue to claim that regular oil changes will stop damaging particulates from forming as we all know full flow filters dont have the filtration efficiency to deal with it properly.

Lets try to explore some facts:

1. We know certain size particulates cause wear.
2. Studies have shown that the sizes we are most concerned about are probably from 3 microns to 25 microns or so because of the limitations of full flow oil filters.
3. It is possible, and it is indeed done, to measure oil for lubricant cleanliness under an ISO standardised 4. 6, and 14 micron composition.
4. Studies have shown that even short OCI UAOs do have 4. 6 and 14 micron particulate contamination. The idea that regular changes will prevent this has been proven to be utterly false.
5. The only way to reduce the wear caused by these size of particulates is to implement a system designed to deal with it.

The rest of your post about engine life in other situations is off topic to the thread. It isnt about dino oil vs synthetics or other subjects.

 

[nullack]

Originally Posted By: Gary Allan
First, to accumulate 450k ..even on a 30 year old chassis, you're doing enough mileage to extend drains. Since a 30 year old chassis is not likely, cutting it to 15 years old (thoroughly believable) ..you're at 30k/year. That's 10 OCI's @ 3k.


I dont want to get offtopic again for this thread but to quickly address these points youve made. In my country quite a few trucks get around with 30 year old chassis. My pickup truck has 785 000 klms on it, a friend did over two million in his, others have clocked it over one million. Diesel engine rebuilds arent cheap......

 

[Gary Allan]

Here we have financial incentives to ..hmmm..how do I say this .."down cycle" our front line offerings to the secondary market in a rapid manner. We also seem to manage to make extended owning less favorable to buying new. Naturally, I'm talking most passenger cars and lighter duty trucks.

..but speaking diesel ..it's been in wide use in your nation for a long time (in the light category) ..while ours it has not. One can have a 25 year old diesel ...or a 300k diesel from the late 70's ..and probably have enough company (units in still in the field) to still have parts made for it ..and professionals to do the work.

For us to have viable diesel, you either have to go so heavy duty that the cost difference neutralizes the advantages for "economy" ..or you have to wait until Detroit comes up with a throw away diesel (slated for next year from GM).

Your core economy probably isn't wrapped so tightly around the automobile.

 

[dnewton3]

I do understand that particle analysis shows interesting data that seems to point to the conclusion that bypass filtration is best for longevity.

I need to re-read my posts, but I thought I had made the point that anything less than 5um is a moot point; they don't cause damage. I believe I said the danger zone is 5-15um. There are two causes of large particles; one is a particle that simply starts large, while the other is one where it grows. Particles that are large at inception will likely be caught soon by the full flow filter. Particles that start small will stay small for quite some time, before they grow. What I was trying to point out is that it's not filtration that controls particles that are small; it is the oil. The dispersants and detergents keep those small particles, well, small. Only after the additive package is overwhelmed, do the small particles become big.

Further, there is interesting logic to review concerning bypass filtration. Most people would agree that bypass systems only see 5-10% of the total circulatory flow. Let's just use 10% because it's easy to use for calculation. Bypass fitlers can reasonably catch particles 2-3um in size. I don't care about anything smaller than that, so the debate below that is moot. So, the absolute efficiency of the bypass fitler is very good. Unfortunately, the bypass fitler only gets to "filter" 10% of the total system flow. That allows us to conclude that any particle that is (for example, say) 8um, will go around the entire engine pathway 9 out of 10 times before being caught by the bypass filter. A bypass filter is great at what it does, but it only get's to do it's job 10% of the total time. 90% of the time, particles never head towards the bypass fitler. So, what do we conclude? Most of the damaging particles see a long and full life in the full flow system. Whatever your stand is on bypass filtration, you cannot avert the percentage of occurence (the mere presence of contamination in the system as a whole). 90% of the time, bypass fitlers do nothing for you. If you argue that the filter helps often because it catches a lot of stuff, by right, that means there's a lot of stuff floating around that it never catches. If you argue that there is very little stuff as an overall occurence, then by right, that means the bypass filter is only effective a very small amount of the time. Folks, 10% is 10%, no matter how you look at it.

The larger the particle size becomes, the less frequency of occurence there is in the system. Also, after a particle becomes large enough, the full flow fitler has an ever greater chance of catching the particle.

So, anything less than 5um is pretty much meaningless because it is the oil that controls it, and anything larger than 15um is likely caught soon after inception by the full flow filter. That leaves a moderately narrow window for the bypass fitler to work upon. The bypass fitler only stops 10% of the system occurence per unit circulated, and is only SOLEY in control above 5um.

Given a 10 quart system, with a full flow and bypass filter. Anything below 5um is being controlled by the oil. UOAs show that wear can be kept low if the oil is changed before 10k miles. 90% of the time, the oil never goes into the bypass filter at all, so 90% of the particulate never gets stopped. That means that only 1 quart of oil is "cleansed" for every 10 that go around. And that 1 quart of oil was likely being well controlled by the additive package anyway, because if you change your oil often enough, it's clear that low damage rates occur. So your bypass filter actually has a very, very small effective window. The bypass is filtering only 1 quart of oil, and that 1 quart of oil was likely already being kept in control by the oil. So, what effect did the bypass filter really have? Very, very little. It's only AFTER the oil becomes overwhelmed, does the bypass filter really become uniquely effective, doing what the oil no longer can. Most everything is already going right around the bypass, and if large enough, is being caught at the full flow filter. So, in essence, perhaps only a few ounces of oil are TRULY being effected out of 10 quarts for every unit of circulatory measure. That is a very small effect, folks.

And you cannot refute the pure anecdotal evidence of the two Chevy trucks that went one-million miles with just short OCIs. That does point to the conclusions that there are two distinct paths to the same end. You either filter out contaminants with super filtration, or you flush them out with an OCI.

As for data to support my conclusion, all you have to do is start tracking UOAs, comparing and contrasting the results. I've got over 130 diesel UOAs in my study. What I see is that up until a certain point (a bit different for each family of diesel engine), the wear rates are nearly the same, comparing full flow to bypass filtration. Only after the oil become overwhelmed, does the disparity become obvious. The wear metals, the insolubles, they all show this to the same conclusion. Just because there is particulate matter in the system, does not automatically mean it's actually doing damage. The damage comes only from the over-abundance of particulate that is not being controlled. That threshold level is much higher that people would think.

Equipment longevity comes from clean lube systems. That clean system can be achieved by either filtering or flushing.

I understand that you want to keep this to the topic of filtation and not economy, but the reality is that bypass filtration is an economic tool. It is a means to an end; equipment longevity. It is, however, not an exclusive means to that end. If not exclusive, then what is the singular benefit it offers? Cost reduction via fewer OCIs.