2016 Dodge Charger 3.6L 66,000 total miles 11,000 miles on HPL 5w-30 HDEO CJ-4

[dnewton3]

I am ignoring some of the statements made like," that sludge'l getcha everytime", but I agree with the statement made tangentially by Bill7.

A shorter OCI will be seen to be more beneficial over a long (10k or more ) over all engines, oils, climates, usage patterns, etc. (all variables combined). If one could combine all the engines in the world and log all these factors. I don't think anyone can reasonably argue with that. The best case to be made for a long OCI is that it doesn't do harm vs a shorter one, not that it is superior in some way. The reverse is true for a short OCI. The bias for a superior schedule lies with the shorter OCI, across all variables. I don't think that is arguable.

I would ask that you define "more beneficial" specifically.
I'm not in agreement with your statement, but I'm willing to hear you out.

I say this because I have wear data (wear rates and wear trends) from about 35,000 UOAs in my database. I can tell you the general trend in wear rates indicates that, overall, there is benefit to running a longer OCI. The wear rates drop in pretty much every single engine series I've ever studied.

Further, the data I have also indicates that contamination (soot, oxidation, coolant, silica, fuel) are parameters which must be monitored, but they do not become obscenely invasive as long as the systems are operating properly. When some form of contamination is present in an undesirable level, then that system needs addressed.

The "superior" aspect of longer OCIs is
- it is a cost savings
- it does, most frequently, result in a lower wear rate out to 15k miles (my data stops there, so I cannot attest to what the phenomenon exhibits past that point)

I will define OCI durations:
* short = 5k miles or less
* moderate = 5-10k miles
* extended = greater than 10k miles

There are always exceptions to the rule. Some infamous engines such as the Toyota's which sludged up; the Saturn SL2s which had no drain-back relief in the piston rings. But those are isolated in grand scheme of things.

The debate comes from this concept ...
When someone says some duration of OCI is "better" or "worse" than another, it's best to ask "Relative to what?"
Some people say a 5k mile OCI is "best". OK - best at what? If one does not measure objective parameters, then only subjective opinions prevail. I prefer to look at real world data. If "short" OCIs are "best", then would super short OCIs be even better than best? Would a 4k mile OCI be "better" than a 5k mile OCI? If that's true, would 3k miles be better than 4k miles? Why not 2k miles? Is a 1k mile OCI optimum???????

As I said, I disagree with you assessment, but I'm willing to hear you out. Please put up the data which supports your side of the debate. All the data I have (thousands upon thousands of UOAs) points toward longer OCIs being generally of benefit in that they not only save money, but result in lower wear rates, all while not risking severe contamination; this data exists across nearly all engine series I've ever studied with rare exception. See this for a rudimentary example:

Used Oil Analysis: How to decide what is normal - Bob is the Oil Guy

Reviewing UOA Data Used oil analyses (UOAs) are tools. And like most tools, they can either be properly used or misused, depending upon the application, the user, the surrounding conditions, etc.= There are already many good articles and publications in existence that tell us how to interpret...

bobistheoilguy.com

If you want to speak to specific engine series, let me know what you're interested in and I can see if it's one of the many I have in my study data.

 

[KEVINK0000]

I do not have a database, and I also stand by my statement. Even a large database such as yours is not conclusive. There are millions of engines that do not appear in your database. To use it, even though its large, as a representative sample of all the engines in use, everywhere, which I was using as an example, is likely going to net out as inaccurate, because the likelihood of the neglected or indifferently, and dealer maintained (the owner has no idea what a UOA is) engines showing up there is probably small. I believe even at 35K, your database is not representative of the real world, since even having knowledge of UOA and paying to have it done by default creates it's own group, that may only represent itself, but not be a sample that can reliably be extrapolated too far. It is interesting however, and I have heard that wear numbers trend down the longer the OCI.

Sometimes common sense trumps a large data set. It has in this case in my opinion.

"The best case to be made for a long OCI is that it doesn't do harm vs a shorter one, not that it is superior in some way. The reverse is true for a short OCI. The bias for a superior schedule lies with the shorter OCI, across all variables. I don't think that is arguable."

That is the extent of what I said.

 

[RDY4WAR]

Shorter OCIs are attributed to higher wear rates due to the stripping of anti-wear films in the first few hundred miles after an oil change. Fresh detergents and other surface aggressive additives and base oils will attempt to strip the old films faster than the new oil's anti-wear additives can reestablish those films. It's common to see a higher wear rate for the first 500 miles or so before leveling off. The more often you change the oil, the more frequently you're putting the engine through that cycle. (and much more oil being wasted)

Changing the oil more frequently doesn't guarantee you won't have sludge and sealing issues. Much of the problems associated with high oil volatility (from lower quality oils) occur from the first time the oil warms up. An oil can't clean around the rings well if it's evaporating from the heat in said area. That's why ester, with high solvency and a boiling point of >600°F, is the preferred choice for cleaning ring and piston deposits.

 

[dnewton3]

I do not have a database, and I also stand by my statement. Even a large database such as yours is not conclusive. There are millions of engines that do not appear in your database. To use it, even though its large, as a representative sample of all the engines in use, everywhere, which I was using as an example, is likely going to net out as inaccurate, because the likelihood of the neglected or indifferently, and dealer maintained (the owner has no idea what a UOA is) engines showing up there is probably small. I believe even at 35K, your database is not representative of the real world, since even having knowledge of UOA and paying to have it done by default creates it's own group, that may only represent itself, but not be a sample that can reliably be extrapolated too far. It is interesting however, and I have heard that wear numbers trend down the longer the OCI.

Sometimes common sense trumps a large data set. It has in this case in my opinion.

What would be conclusive to you; sample every single car/truck engine ever made???? That's not practical; it's not even achievable.
Macro-data statistical processing/analysis is used in every walk of life, every day, all around the world. Further, that same methodology has been applied to mirco-datasets as well. Same phenomenon occurs; longer OCIs = lower wear rates, as a generalization.

Your "common sense" is perhaps common, but not sensible; it's rhetoric, mythology and emotion all wrapped up in denial. You have every right to believe what you want; no one can take that away from you. Your beliefs don't seem to be based on anything substantial in terms of proof; you've presented no data to back up your claims. My beliefs are based on education, training, experience and many tens of thousands of data points processed in methodical, articulate fashion; a system which is practiced worldwide.

Several members here have asked you to dial in the proof of your claims; to present data or studies which lend creedence to your position. All you've done in response is retort with vagueness and counter accusations. This does not help us understand your position; it only makes us doubt your credibility.

We can agree to disagree.

 

[KEVINK0000]

I definitely agree to disagree. What I am basing my claims on is indeed common sense, not rhetoric, mythology, or emotion.

I stated what I stated, and I believe that statement to be true. I understand what you are saying, but I don't think you understand what I am saying.

Think for a few minutes beyond what you have been trained to know. I know that sounds weird, but there it is.

My claim is less of a leap than yours, even though you can present figures, and I cannot.

Again, here is what I am saying:

"The best case to be made for a long OCI is that it doesn't do harm vs a shorter one, not that it is superior in some way. The reverse is true for a short OCI. The bias for a superior schedule lies with the shorter OCI, across all variables. I don't think that is arguable."

 

[53' Stude]

I definitely agree to disagree. What I am basing my claims on is indeed common sense, not rhetoric, mythology, or emotion.

I stated what I stated, and I believe that statement to be true. I understand what you are saying, but I don't think you understand what I am saying.

Think for a few minutes beyond what you have been trained to know. I know that sounds weird, but there it is.

My claim is less of a leap than yours, even though you can present figures, and I cannot.

Again, here is what I am saying:

"The best case to be made for a long OCI is that it doesn't do harm vs a shorter one, not that it is superior in some way. The reverse is true for a short OCI. The bias for a superior schedule lies with the shorter OCI, across all variables. I don't think that is arguable."

I’ll side with actual data and dnewtons knowledge. Your statement doesn’t make it truth to everyone. We all have our thoughts and opinions; and you have yours.


End of discussion, have a great day

 

[dnewton3]

... but I don't think you understand what I am saying.

I hear what you're saying; I just find untennable. I don't understand it because it defys logic based on facts and instead relies on specious assumptions and flawed narative.

In a sense of fairness, I'd like to take another stab at this to try and understand your POV. Seriously - I'm not trying to pick on you here. I'm all ears if you can help me understand your position. But to do so, I don't want to rely on rhetoric or mythology. Let's stick to parameters which can be articulated, quantified and proven. If you insist on your claim being right, and that's fine by me for you to do so, then please help me understand what you are using to measure the success of shorter OCIs?
Here are the things most of us would accept as tangible proof:
* wear-metal rates
* fiscal conservancy
Note that contamination rates don't change over an OCI, so this is a "constant" that is not affected by OCI duration. Parameters not influenced by the variable do not exhibit correlation, therefore no causation is proven. Contamination rates are moot. So we're going to put this topic aside. The only thing that would alter a contamination rate is for some physical control system to develop a flaw; a head gasket leaks more coolant; an air filter intake tube gets a crack and leaks air; fuel injector leaks into combustion chamber; etc ... These can be detected by UOAs and then subsequently fixed. And, the OCI duration cannot stop any of these ruinous problems; only repairs can fix these issues. So OCI duration does not play into contamination rates.


I'm going to separate your statement out, so that we can try to find the basis for your claim:

"The best case to be made for a long OCI is that it doesn't do harm vs a shorter one, not that it is superior in some way.

The first "superior in some way" trait is that wear-rates for the main metals (Fe, Al, Cu, Pb, Cr) all go lower as the OCI matures out to 15k miles. This is proven in results of macro and micro analysis. Not only does a longer OCI not do harm, it is truly beneficial in this manner.
Q1- do you believe lower wear-rates associated with longer OCIs to be inferior? If so, how?

Further, another "superior in some way" trait is that fewer oil changes saves money for the user.
Q2- do you believe that money savings inherrent with longer OCIs to be inferior? If so, how?

Also, longer OCIs are "superior in some manner" because less oil is consumed in a macro manner; less raw natural resources extracted from the earth, lower energy requirements for lube refinement, fewer production needs (packaging and shipping), and less recycling efforts needed at disposal time. For every OCI that is extended from 5k to 10k miles, that cuts in half the total effort needed to replace and recycle that same quantity of lube.
Q3- do you believe that less demand on oil and energy in a global format is a bad thing? If so, how?

The reverse is true for a short OCI.

What is it that is true here? A shorter OCI is to be considered superior? How so?
Q4- are the higher wear-rates present in shorter OCIs are desirable?
Q5- is spending more money than necessary for acceptable engine protection is desirable? (aka ... wasting money is somehow attractive?)
Q6- is using more natural resources and higher energy consumption in producing more lubes is a good thing?

The bias for a superior schedule lies with the shorter OCI, across all variables.

You clearly have a "bias", but I fail to understand how you see this to be true. What quantifiable measure are you relying on to make this assertion? Wear rates and fiscal ROI all point to longer OCIs being favorable. So is there some other means of measuring the value of an OCI that you are using for your "bias"? The variables are listed above; how is it you see using more oil and more money to get higher wear rates as a postive bias?

I don't think that is arguable.

Let's set aside the word "arguable" and call it debate. I believe that debate clearly shows your position as lacking substantive logic thus far. But I'm open to hear about anything you can add IF you can find credible sources of attribution.

I see two opportunities to have you prove your point:

1) you need to find proof that counters my facts of lower wear rates and money savings being desirable. The problem is, you've already admitted you don't have data to back up your claim. You said this:

... even though you can present figures, and I cannot.

If you cannot come up with data that counters mine, then what is the basis for your position? You have an opinion. OK - fine. But opinions are usurped by tangible facts.

2) you need to come up with some other means of objectively (not subjectively) assessing OCI duration not already identified above. If wear rates and financial considerations are already covered, and contamination is moot, what else can be used to judge the viability of an OCI?


I will summarize my position here ...
The following statements are generalizations which would exclude known "problem-child" engines (aka sludge engines, poorly maintained engines, etc):
- Short OCIs won't hurt an engine, but they will hurt your wallet
- Long OCIs won't hurt an engine, and can in fact reduce wear rates, and they will also help your wallet, and lessen global resource draws

Conceptually, any OCI can be too short or too long; the right way to select a lube is to identify the quantifiable parameters, define and decide condemnation limits, and then monitor the results and make decisions after all data is reviewed.


If you want folks, including me, to take you seriously, then please bring something objective (not subjective) to the discussion.

 

[Greasymechtech]

This engine needs a Frantz filter, a new roll of TP every 5k, full flow filter changed whenever the OP wants to, top off with same oil for filter changes, and never ever another oil change.

 

[53' Stude]

This engine needs a Frantz filter, a new roll of TP every 5k, full flow filter changed whenever the OP wants to, top off with same oil for filter changes, and never ever another oil change.

 

[Nesterenko]

Think for a few minutes beyond what you have been trained to know. I know that sounds weird, but there it is.

I believe it is you who should adhere to these words. You're the one that's not budging on what you were trained to know since God knows when.

 

[KEVINK0000]

DNewton: I appreciate the effort for serious discussion, so I will do my best to respond properly. Time is at a premium, and I don't want to fire off a short answer.

I will answer the question about Overkill's post also.

 

[The Critic]

On the flip side, Toyota uses a mileage counter, which takes none of these parameters into account. They will argue this is fine. The counter here is that there's been some anecdotal evidence presented by mechanics that it isn't fine, and my personal opinion on that matter is that this is, at least in part, the result of using a simple mileage counter rather than an IOLM.

I think that is a somewhat misguided interpretation of the situation. From an OEM standpoint, some level of oil consumption is acceptable and limits are clearly outlined in the owners manual. A lot of recent warranty extensions for oil consumption are driven by "customer satisfaction" issues, not so much performance issues. Toyota likely validated those service intervals based on a worse case scenario and feels they are more than adequate for the stated conditions. Their maintenance schedule clearly outlines a list of conditions where the shorter 6mo/5K interval is mandatory.

Which is far removed from this current tangent about what best serves Joe Average, the OEM interval or the Jiffy Lube one and subsequently my reply to your post.

Wayne isn't Joe Average, he's not partaking in this exercise from a position of ignorance and the individual in question, catastrophizing per the above, is soundly ignoring Wayne's knowledge and his reasoned approach, instead making conclusive claims about the condition of Wayne's equipment and accusing him of severely neglecting it because he's not following the Jiffy Lube schedule.

These are two very distinct discussions, but this last page has managed to mire them all into one giant steaming pile.

While I think Wayne has made a conscientious effort at validating his extended drains using oil analysis, this is a situation where some of us simply "agree to disagree." I recognize that UOA's are a tool that has their limitations and I am skeptical that we are getting the entire picture of lube and engine health thru the lens of this tool. Obviously the OEM's have different objectives (and requirements) in mind when setting their service interval, but in the absence of access to the resources they have, I am extremely leery of going this far beyond the OEM interval using any lube. Again, not saying 3mo/3k is the right answer, but we are discussing two extremes...

 

[OVERKILL]

I think that is a somewhat misguided interpretation of the situation. From an OEM standpoint, some level of oil consumption is acceptable and limits are clearly outlined in the owners manual. A lot of recent warranty extensions for oil consumption are driven by "customer satisfaction" issues, not so much performance issues. Toyota likely validated those service intervals based on a worse case scenario and feels they are more than adequate for the stated conditions. Their maintenance schedule clearly outlines a list of conditions where the shorter 6mo/5K interval is mandatory.

So your position is that a mileage counter is equal in its ability to dictate an appropriate interval as an IOLM? Because if so, I'm going to have to vehemently disagree.

We can list-off numerous situations here, even WITH IOLM's, where the OE interval, assumingely arrived at through the same sort of testing you are implying took place at Toyota, is wildly out of whack with reality in terms of what was appropriate. Honda's VCM engines are a prime example, GM's HF V6 is another. Toyota's sludge monsters? I think we must assume that these were also tested. These OEM's aren't infallible, the choice of a mileage counter over an IOLM is one driven by cost not the end user's best interest and it will always be inferior to a true IOLM because it has zero adaptability.

Relying on Joe Average to follow the language in the manual and determine when he's severe service and thus should be running a shorter interval is severely over-estimating his abilities. This is another advantage for the IOLM, because it tells Joe he needs to change the oil, it knows when a shorter interval is required, like when my wife's truck says it needs changing at 10,000km (6,200 miles) rather than the 14,000km (8,700 miles) it dictated previously.

While I think Wayne has made a conscientious effort at validating his extended drains using oil analysis, this is a situation where some of us simply "agree to disagree." I recognize that UOA's are a tool that has their limitations and I am skeptical that we are getting the entire picture of lube and engine health thru the lens of this tool. Obviously the OEM's have different objectives (and requirements) in mind when setting their service interval, but in the absence of access to the resources they have, I am extremely leery of going this far beyond the OEM interval using any lube. Again, not saying 3mo/3k is the right answer, but we are discussing two extremes...

As you know, I don't draw out my intervals past what the IOLM dictates, and that interval changes significantly depending on the season and how the vehicle is used. Whatever our personal positions on running intervals of this duration, we can certainly agree that Wayne isn't ignorant on this subject and that even the OE interval would fall under what the aforementioned poster called "abuse" because of how he defined it.

When Doug Hillary did his long drain testing he verified it with tear-downs. That very much "answer the question" that you feel is not being addressed here. How do we validate performance beyond what the UOA shows? and I totally get that and your lack of confidence in just relying on oil analysis.

Circling back to the 10K interval however, I do think that with an appropriate lube, conditions and application, this is totally achievable and not "unbridled abuse".

 

[The Critic]

So your position is that a mileage counter is equal in its ability to dictate an appropriate interval as an IOLM? Because if so, I'm going to have to vehemently disagree.

We can list-off numerous situations here, even WITH IOLM's, where the OE interval, assumingely arrived at through the same sort of testing you are implying took place at Toyota, is wildly out of whack with reality in terms of what was appropriate. Honda's VCM engines are a prime example, GM's HF V6 is another. Toyota's sludge monsters? I think we must assume that these were also tested. These OEM's aren't infallible, the choice of a mileage counter over an IOLM is one driven by cost not the end user's best interest and it will always be inferior to a true IOLM because it has zero adaptability.

Yes, because if the recommended interval is conservative enough for all potential conditions, then having a "dynamic" OCI is not required. Also, the examples you are citing are getting a bit old....the newest example (Honda VCM) is getting pretty old.

Relying on Joe Average to follow the language in the manual and determine when he's severe service and thus should be running a shorter interval is severely over-estimating his abilities. This is another advantage for the IOLM, because it tells Joe he needs to change the oil, it knows when a shorter interval is required, like when my wife's truck says it needs changing at 10,000km (6,200 miles) rather than the 14,000km (8,700 miles) it dictated previously.

In your example, if the OEM had specified an interval of 3,000 miles or 5,000 miles, it would have taken both situations into account. Stellantis has simply chosen to incorporate a dynamic component to the service interval which sometimes allows for it to be pushed out further, but this has its pros/cons. From what I have heard, customers prefer to have a consistent, predictable service schedule for planning purposes - and this is an example that will not go well with some customers.

Furthermore, reading the owner's manual is a user responsibility. Oil changes are not the only component of vehicle maintenance (or ownership) that has adverse consequences if the user fails to follow the manual.

As you know, I don't draw out my intervals past what the IOLM dictates, and that interval changes significantly depending on the season and how the vehicle is used. Whatever our personal positions on running intervals of this duration, we can certainly agree that Wayne isn't ignorant on this subject and that even the OE interval would fall under what the aforementioned poster called "abuse" because of how he defined it.

That is subjective - but going 27.5 months vs. OEM maximum of 12 months could be interpreted as abuse by some folks. I am a bit concerned about keeping contaminants in the crankcase for this amount of time and I have not seen any controlled studies indicating one way or another. I want to say that over 10 years ago, some Euros allowed up to 2 years between services on some full-SAPS lubes, but even this was reduced down to 1 year.

When Doug Hillary did his long drain testing he verified it with tear-downs. That very much "answer the question" that you feel is not being addressed here. How do we validate performance beyond what the UOA shows? and I totally get that and your lack of confidence in just relying on oil analysis.

For that example to be remotely applicable, Wayne would have to tear down this engine and have more than one example in this experiment.

 

[OVERKILL]

Yes, because if the recommended interval is conservative enough for all potential conditions, then having a "dynamic" OCI is not required. Also, the examples you are citing are getting a bit old....the newest example (Honda VCM) is getting pretty old.

I didn't think there was an age threshold on the validity of examples The problem is, there is clearly evidence that the recommended fixed interval may never be conservative enough and there's evidence in this discussion that this is the case with Toyota's 10K interval. The counter is obviously that Joe Blow needs to read and understand his manual and that this should cause him to run a shorter (fixed) interval but how do we know even that is short enough depending on the conditions? But the bigger issue, and the reality, is that he won't. He'll wait until the mileage counter goes off and tells him to change the oil.

In your example, if the OEM had specified an interval of 3,000 miles or 5,000 miles, it would have taken both situations into account. Stellantis has simply chosen to incorporate a dynamic component to the service interval which sometimes allows for it to be pushed out further, but this has its pros/cons. From what I have heard, customers prefer to have a consistent, predictable service schedule for planning purposes - and this is an example that will not go well with some customers.

Both of which are insanely short intervals by modern standards, which OEM's are all trying to get away from. And no, neither of this intervals takes either situations into account, they are heavily fudged estimates hoping to err on the side of being safe, it's like carpet bombing a city hoping you kill the terrorist instead of using a drone strike.

As a technical person, I greatly prefer my vehicle to actually take my driving style, ambient conditions, idle hours and other factors into account in determining when I should change my oil. And I can easily see the estimated percentage remaining on the bloody cluster, so it's not like SURPRISE DUDE YOU ARE AT ZERO! while I'm on vacation or something stupid. Furthermore, expecting Joe Blow to go "oh, I'm going to short trip a lot this month, better drop my interval down to 6,000 miles" while his BDOLM continues to mindlessly run toward 10K, that's not going to happen, and it's arguably MORE inconvenient from a planning perspective because you need to know what your driving profile is. Being able to check the IOLM is comparatively much simpler and it adapts "on the fly".

Furthermore, reading the owner's manual is a user responsibility. Oil changes are not the only component of vehicle maintenance (or ownership) that has adverse consequences if the user fails to follow the manual.

Right. And yet we know they don't read the manual. Christ, how many people come here and start threads asking what oil their vehicle takes? and this is a bloody oil forum! At least with the OLM popping up saying "CHANGE OIL!" there's a better chance that's going to actually get dealt with.

That is subjective - but going 27.5 months vs. OEM maximum of 12 months could be interpreted as abuse by some folks.

Then I guess I abuse both my vehicles And have abused every one I've ever owned since I've never changed at the 12 month mark. I'm coming up on 1 year in the Jeep right now actually, last changed June 26th, 2022. Will also be running the same D1 5W-40 fill in the Supra this summer since it only has ~30 hours on it.

I am a bit concerned about keeping contaminants in the crankcase for this amount of time and I have not seen any controlled studies indicating one way or another. I want to say that over 10 years ago, some Euros allowed up to 2 years between services on some full-SAPS lubes, but even this was reduced down to 1 year.

BMW had the 2-year max interval (from my M5 manual), since the OLM obviously couldn't take age of the lubricant into account:

For that example to be remotely applicable, Wayne would have to tear down this engine and have more than one example in this experiment.

That's what I'm driving at. That's the body of evidence you would deem sufficient in order to be comfortable with this interval in this application.

 

[The Critic]

I didn't think there was an age threshold on the validity of examples The problem is, there is clearly evidence that the recommended fixed interval may never be conservative enough and there's evidence in this discussion that this is the case with Toyota's 10K interval. The counter is obviously that Joe Blow needs to read and understand his manual and that this should cause him to run a shorter (fixed) interval but how do we know even that is short enough depending on the conditions? But the bigger issue, and the reality, is that he won't. He'll wait until the mileage counter goes off and tells him to change the oil.

I'll just add that Toyota specifies a 10K OCI for most conditions, but they (along with me), are a big proponent of regular vehicle inspections. The maintenance light always comes on at 5K intervals for the tire rotation and inspection; the oil change is supposed to take place every other visit.

I'm sure the "Average Joe" has a super-hard time with grasping this.

 

[OVERKILL]

I'll just add that Toyota specifies a 10K OCI for most conditions, but they (along with me), are a big proponent of regular vehicle inspections. The maintenance light always comes on at 5K intervals for the tire rotation and inspection; the oil change is supposed to take place every other visit.

I'm sure the "Average Joe" has a super-hard time with grasping this.

Well, according to the Car Car Nut, these 10K Toyota intervals are an epidemic because people are religiously following them

 

[The Critic]

Well, according to the Car Car Nut, these 10K Toyota intervals are an epidemic because people are religiously following them

That was kinda what I was getting at. Average owner doesn't really service their vehicle on time, anyway. So that 5K visit becomes 7K, then the next one becomes 6-7K as well. So, the intended 10K interval really ends up being closer to 14-15K. If I had to guess, that is probably the real cause of the issues.

 

[OVERKILL]

That was kinda what I was getting at. Average owner doesn't really service their vehicle on time, anyway. So that 5K visit becomes 7K, then the next one becomes 6-7K as well. So, the intended 10K interval really ends up being closer to 14-15K. If I had to guess, that is probably the real cause of the issues.

Yep, so we couple that with the fact these folks aren't reading the manual, so they have no idea what the severe service interval IS let alone whether they qualify for it or not, and well, here we are.

That's again one of the reasons I think an IOLM is a better method for determining OCI length. My wife doesn't watch the OLM at all; she has no idea how many km she has left, but it gives you a warning at 5% and that's when she typically lets me know: "hey, the truck is telling me I need to change the oil soon". Followed later by "the truck is at zero, you gotta change the oil so it stops bugging me." It's intrusive enough that someone like her, who doesn't follow the maintenance schedule and couldn't tell you two words from her manual knows that the oil needs to be changed.

Amusing anecdote: My dad's Town Car has the Ford "OLM" which I think is just a mileage counter. Think it starts off at like 15 or 20,000km? Dad tends to run it a max of about 10-15,000km on M1, but it's funny as he regularly checks how many km the vehicle says he has left and sometimes he calls me and lets me know, looking for my input on whether he should change it or not, lol. When he changes it, he religiously writes it down in his vehicle maintenance log. I think the car is 20 years old this year? hahhahah.

 

[vinu_neuro]

I am a believer in long intervals with quality oils (within reason based on oil quality and driving patterns). For one thing, it is just less wasteful.

However, I wouldn't do 10k+ mile intervals without also having a TAN measurement to actually confirm the acids are being neutralized, especially if the oxidation measurement is not as useful because of a high-ester chemistry.