'17 Toyota Highlander V6 3.5L 2GR-FKS - SuperTech Advanced Full Synth 0W-20 10,368 miles

Hey all,

This is the first oil report I've done and it's on my 2017 Highlander XLE 3.5L V6 that has just over 70,000 miles. I used SuperTech Advanced Full Synthetic 0W-20 for 10,368 miles which was in use for 9 months. The ST bottle claims 20,000 mile protection, but I've no interest in going over Toyota's recommendation of 10,000 miles or 12 months. This is our daily driver/kid hauler and sees approximately 70% city driving, some mountains/hills, and a wide range of ambient temps. The engine oil filter I use is the Toyota 04152-YZZA1 and the engine air filter is Toyota 17801-YZZ11. I was particularly interested to see how this report would come out since this is the 2GR-FKS engine that has the ever-so-annoying start/stop technology. I've always been concerned it adds unnecessary wear & tear. Everything looked good to me on the report and I see no reason to change anything. What do you folks think?

View attachment 92082
Soobs Great Report!
Oil stayed in Grade, Plenty of TBN left You could probably run a 15k mile OCI
I look forward to your next report!
 
Well maybe this article dnewton3 posted in another thread will change your anecdotal tune. Credible source says frequent oil changes actually increase wear. Your methods are actually slightly harmful.
That's outrageous! No possible way in hell you are going to damage a motor by changing the oil too much. That article is nonsense.
 
That's outrageous! No possible way in hell you are going to damage a motor by changing the oil too much. That article is nonsense.
Let's be careful with the details here.

What is totally, completely true to say is that shorter OCIs see higher wear rates. There are (literally) tens of thousands of UOAs in my database that prove this beyond any doubt. But that does not mean those rates are harmful or will end up in "damage" to the engine. The article is not "nonsense". The "nonsene" comes from people who misunderstand and/or misquote the fundemental concepts of the article.

The following is accurate and true:
Shorter OCIs have higher wear rates. Longer OCIs have lower wear rates. The longer you run the lube, the lower the wear rate will be. (Limited to 15k miles because that's where most of my data stops).
 
That's outrageous! No possible way in hell you are going to damage a motor by changing the oil too much. That article is nonsense.

The way a tribologist explained it to me in layman's terms is thus; Oil is caustic. The aggressive additives come with a price. It becomes less caustic as those additives deplete until the pendelum swings and as the acids build it starts becoming more caustic again.

That said it's going to be lot better to drastically over service than under service. An engine with 100 mi OCI with 25K Oil is going to last a lot longer than using Store Brand X Blend as a lifetime fill.

When this site first started their seemed to be more willingness to match the lubricant to the desired interval. An idea that the best 15,000 mi oil didn't necessarily make the best 3,000 mi oil. I've noticed some support for that. Very vanilla oils often appear to me to show lower metal numbers than the more highly regarded oils when intervals are short.
 
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Let's be careful with the details here.

What is totally, completely true to say is that shorter OCIs see higher wear rates. There are (literally) tens of thousands of UOAs in my database that prove this beyond any doubt. But that does not mean those rates are harmful or will end up in "damage" to the engine. The article is not "nonsense". The "nonsene" comes from people who misunderstand and/or misquote the fundemental concepts of the article.

The following is accurate and true:
Shorter OCIs have higher wear rates. Longer OCIs have lower wear rates. The longer you run the lube, the lower the wear rate will be. (Limited to 15k miles because that's where most of my data stops).
Apologies for using misleading adjectives. I was using them in a relative sense and didn't mean to spread the wrong message.
 
The following is accurate and true:
Shorter OCIs have higher wear rates. Longer OCIs have lower wear rates. The longer you run the lube, the lower the wear rate will be. (Limited to 15k miles because that's where most of my data stops).

I don't believe it. Unless your data shows engines disassembled and parts measured to show the wear. And only after each engine was run at the exact same temp's, rpm's and exact matching variables. There is no proof whatsoever to substantiate that article. Oil samples are a small indicator of engine wear using only lubricating properties as a base for comparison.
 
Unless you took apart the motor before you traded it in then you have no clue as to it's condition. And you make my point. You traded it in. So any OCI's are a moot point because the miles were low when you unloaded it.

I'm not here to change anyones mind as to "how many miles". We all have a routine we stick to. Mine is 3,000 OCI on my 4 wheeled vehicles (5K max if going cross country), 1K on my Super Tenere with shared transmission/engine oil and 10 hours on my dirt bikes.


Well I'm not a tree hugger or some freak environmentalist. I recycle my oil or dispose of it properly at a hazmat center. I choose to take pride in keeping my vehicles in the best shape as possible.
Definitely not a tree hugger. They aren't absurdly wasteful especially with the availability of great engine oils at hand.
 
The way a tribologist explained it to me in layman's terms is thus; Oil is caustic. The aggressive additives come with a price. It becomes less caustic as those additives deplete until the pendelum swings and as the acids build it starts becoming more caustic again.

That said it's going to be lot better to drastically over service than under service. An engine with 100 mi OCI with 25K Oil is going to last a lot longer than using Store Brand X Blend as a lifetime fill.

When this site first started their seemed to be more willingness to match the lubricant to the desired interval. An idea that the best 15,000 mi oil didn't necessarily make the best 3,000 mi oil. I've noticed some support for that. Very vanilla oils often appear to me to show lower metal numbers than the more highly regarded oils when intervals are short.
Also, the metals shed, because of the very narrow range sampled via spectrography, are limited in value. Sure, if you see a huge uptick it may warrant further investigation, but different formulas will have different "signatures" and certain base oil and additive chemistries may chelate material, which shows up as "wear metals" in a UOA, even though no actual increase in physical wear took place. In fact physical wear could be lower. Esters are a prime example of something that will increase metals in a UOA, but not wear.

Also, if we go to the extremes:
An oil that's capable of holding more in suspension than another may show higher levels than the one that can't. Varnish, sludge, these products are also full of whatever else was in the oil and an oil with a weak-sauce additive package that is saturated to the point of laying down deposits may show "better" than one that is more robust. This can also flesh out with a change in lubricants to one that has more aggressive chemistry and has better solubility as well as a more robust detergent/dispersant package when used in an engine that already has deposits from previous OCI's with a lubricant or lubricants that were not capable of those tasks. As those deposits are dissolved, this may artificially inflate the figures seen via a UOA.

A UOA can tell you if you have sufficient TBN remaining, but it doesn't tell you if you've reached the holding capacity of the additive package, and Blackstone doesn't provide oxidation, so there's also a lot of flying blind that can happen, which can be dangerous if the engine in question is particularly hard on oil, like the Honda example that @The Critic shared in another thread.
 
Also, the metals shed, because of the very narrow range sampled via spectrography, are limited in value. Sure, if you see a huge uptick it may warrant further investigation, but different formulas will have different "signatures" and certain base oil and additive chemistries may chelate material, which shows up as "wear metals" in a UOA, even though no actual increase in physical wear took place. In fact physical wear could be lower. Esters are a prime example of something that will increase metals in a UOA, but not wear.

Also, if we go to the extremes:
An oil that's capable of holding more in suspension than another may show higher levels than the one that can't. Varnish, sludge, these products are also full of whatever else was in the oil and an oil with a weak-sauce additive package that is saturated to the point of laying down deposits may show "better" than one that is more robust. This can also flesh out with a change in lubricants to one that has more aggressive chemistry and has better solubility as well as a more robust detergent/dispersant package when used in an engine that already has deposits from previous OCI's with a lubricant or lubricants that were not capable of those tasks. As those deposits are dissolved, this may artificially inflate the figures seen via a UOA.

A UOA can tell you if you have sufficient TBN remaining, but it doesn't tell you if you've reached the holding capacity of the additive package, and Blackstone doesn't provide oxidation, so there's also a lot of flying blind that can happen, which can be dangerous if the engine in question is particularly hard on oil, like the Honda example that @The Critic shared in another thread.

I think TBN is on it's way out. Many engine manufacturers no longer have a TBN condemnation limit. Instead they are looking at Oxidation, Nitration and Sulfation.
 
I don't believe it. Unless your data shows engines disassembled and parts measured to show the wear. And only after each engine was run at the exact same temp's, rpm's and exact matching variables. There is no proof whatsoever to substantiate that article. Oil samples are a small indicator of engine wear using only lubricating properties as a base for comparison.
Well, don’t fret over it too much, that article posted clearly states in the last sentence that more testing is needed and this is only one test. Plus the fleet they tested consternation of three vehicles. And to make things even less relevant they claim that they see wear rates dropping as early as 3,000 miles...which leads one to ask, when exactly is this wear occurring? At 500 miles? 100? 50? No one changes their oil that early anyway. So, technically, I guess you could say that even if you are changing your oil at 3,000 mile interval, you are reaping the “benefits” from this wear “study”, consisting of three vehicle and zero information shared of the capabilities of this tri nuclear coating strength that’s now attached to one tested surface. Or how the vehicles were driven, what surfaces tested, what mileage wear is actually occurring and most importantly, why further testing has yet to be done from a study performed over fifteen years ago...on engines vastly different than today.
 
I don't believe it. Unless your data shows engines disassembled and parts measured to show the wear. And only after each engine was run at the exact same temp's, rpm's and exact matching variables. There is no proof whatsoever to substantiate that article. Oil samples are a small indicator of engine wear using only lubricating properties as a base for comparison.
That's absurdly unrealistic.

Should we "tear-down" an engine every 3k, 5k or 10k miles to do a "wear" measurement?
Or, perhaps you only think it would be valid after 250k miles?
How is Joe Average supposed to do this in his DD? How's he supposed to learn how his lube choices are doing on his meager budget? Is he supposed to give up his car twice a year for a "tear-down" of his engine to see if everythings OK?
Either way, you'll either introduce massive intrustion (frought with potential for error and contamination), or, you'll only find out how well your lube selection did at the end of a very long lifecycle; far too late if you made the "wrong" choice.
In short, no one has the time/money to do engine tear-downs as a means of measuring wear.
Nice try; completely useless knee-jerk reaction to substantiate your disbelief.

UOAs do have limitations; that's true. But they also have great benefits. As long as you understand both, the UOA can be a very useful tool. Entire industries use spectral analysis as a means of a PRACTICAL, TIMELY, INEXPENSIVE means of tracking wear. That fact that you have no faith in it will not dissuade the rest of us from using it. Your disbelief only reveals your lack of understanding of the topic.

Oh, and there's this ... it's incredibly apparent that you didn't actually buy the SAE article and read it; you may or may not have even read the entire summary. If you had paid for the whole study and read it all, you'd know that in the Ford/Conoco study they actually did take valvetrain components, run them in a controlled test, and do a detailed component analysis mesauring component material loss (shedding of wear metals). So, yet again, you reveal your lack of understanding of the topic; you have no idea what you're talking about. If you want to be credible in debating an SAE study, it really helps if you actually read it first.

So the reality is that the SAE study you find so unbelieveable actually used two different, credible means of measuring wear; component analysis and spectral analysis. Those two completely different methods showed excellent correlation in concluding the same truth; wear rates drop as the OCI matures.

You can igore the facts and data all you want. That doesn't make them any less true.
There's a sign that hung in my office before I retired that read:
"I can explain it to you, but I can't understand it for you."
 
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Let's be careful with the details here.

What is totally, completely true to say is that shorter OCIs see higher wear rates. There are (literally) tens of thousands of UOAs in my database that prove this beyond any doubt. But that does not mean those rates are harmful or will end up in "damage" to the engine. The article is not "nonsense". The "nonsene" comes from people who misunderstand and/or misquote the fundemental concepts of the article.

The following is accurate and true:
Shorter OCIs have higher wear rates. Longer OCIs have lower wear rates. The longer you run the lube, the lower the wear rate will be. (Limited to 15k miles because that's where most of my data stops).

Let’s also not forget the effect of residual oil. If one were to perform a UOA 100 miles into an interval there would be considerable wear metals owing to the the contaminated nature of the oil that wasn’t removed during the change (10-20%?). All other reasons aside, this would contribute to higher “wear” rates in a short OCI.
 
Also, the metals shed, because of the very narrow range sampled via spectrography, are limited in value. Sure, if you see a huge uptick it may warrant further investigation, but different formulas will have different "signatures" and certain base oil and additive chemistries may chelate material, which shows up as "wear metals" in a UOA, even though no actual increase in physical wear took place. In fact physical wear could be lower. Esters are a prime example of something that will increase metals in a UOA, but not wear.

Also, if we go to the extremes:
An oil that's capable of holding more in suspension than another may show higher levels than the one that can't. Varnish, sludge, these products are also full of whatever else was in the oil and an oil with a weak-sauce additive package that is saturated to the point of laying down deposits may show "better" than one that is more robust. This can also flesh out with a change in lubricants to one that has more aggressive chemistry and has better solubility as well as a more robust detergent/dispersant package when used in an engine that already has deposits from previous OCI's with a lubricant or lubricants that were not capable of those tasks. As those deposits are dissolved, this may artificially inflate the figures seen via a UOA.

A UOA can tell you if you have sufficient TBN remaining, but it doesn't tell you if you've reached the holding capacity of the additive package, and Blackstone doesn't provide oxidation, so there's also a lot of flying blind that can happen, which can be dangerous if the engine in question is particularly hard on oil, like the Honda example that @The Critic shared in another thread.

First, let's limit our conversation to healthy engines. Equipment that is badly ailing and/or abused with no regular maintenance will not really help this discussion; I exclude those from my comments below.

Metals shed in a UOA are a representation, just as any sample is. If the sample is well taken, the representation is valid. I think those of us who undertand spectral analysis do agree that any particle above 5um isn't likely to be seen, and those that are are somewhat on a sliding scale because smaller particles vaporize with greater consistency than do larger ones. However, that "sample" is still valid. There is inference that can be taken from the wear metals; low values indicate a lower overall total rate, and vice-versa. Furher, as has been discussed elsewhere on this site many times, there are filtration studies that show excellent correlation between particulate loading and wear metals. Low wear metals in a UOA are echo'd in PC tests, meaning that (though the PC cannot see content), there's likely a lower percentage of large metals also in the sample. This is proven beyond any reasonable argument. It would be unrealistic to claim that a low wear metal count in a UOA is somehow hiding massive particles beyond the 5um limit in a normal, healthy engine. That's does not correlate in any manner with the PC studies regarding filtration efficiency. I will admit there certainly are particles of metals above the 5um limit, but that does not mean they are numerous or an indication of pending doom. We take samples of anything in the expectation that the sample gives us a relative view of the overall population. UOAs cannot see the entire metal count in a sump, but they can imply a relative rate of high or low metals overall. UOAs see content, whereas PCs see quantity; they can compliment each other and have shown good correlation between desirable and undesirable conditions of lubes realitive to the equipment they are in. It's true to say UOAs are "limited" in what they can see, but we have the ability to take samples and make an informed inference of the overall wear condition. But I disagree with you when you state they are "limited in value".

I agree completely with you in regard to the topic of esters and chelation. That's been seen quite easily in the GM 6.6L Dmax engines. They shed Cu like a dog sheds a fur in spring, when you introduce an ester-laden lube; that's because the oil cooler is a copper-plate design. However, you didn't also mention that the reaction of the metal to the ester will actualy subside over time as the metal normalizes to that chemistry. That normalization often takes many thousand of miles; often more than one or two OCIs. Which brings me to another point ... changing lube brands every OCI only compounds the issue. When we see folks trying Amsoil, then RP, then RL, and then continue down the oil-de-jour path every OCI, the engine metals never really get a chance to acclimate to the lube before the next is introduced.
But ... I would argue this ... how's that the fault of the UOA? How is that the fault of spectral analysis????
What that shows is a lack of understanding on the part of Joe Average regarding how his choices and actions can skew a test result. If you don't understand the benefits and limitations of a tool you are using, you're likley to misuse the tool, or misinterpret the results the tool provides. That is NOT a indictment of the tool; it's a clear display of ignorance upon the user. A UOA is only as good as the person using it, and frankly we have a lot of amateur hacks on this site grossly misutilizing and misinterpreting UOAs. But that's not the fault of spectral analysis now, is it?

To continue, I understand your comment regarding holding capacity of a lube, but that somewhat looks at the end of an equation and ignores the process unfolding. Just as engines shed metals at some rate, they also experience contamination at some rate. Sludge and silica don't just show up en-mass on day one; they accumlate over time. And the host oil starts out "fresh" with it's given load of anti-oxidants, anti-agglomerates, detergents, etc. Essentially, any oil starts out with 100% of it's ability, and then degrades. Yet the sump contamination starts out (near) zero, and escalates. So as long as the capacity of any one oil to deal with contamiation isn't overwhelmed, it's not really a a big deal to worry about how it fares relative to another lube. Let me show this as analogy; I think it helps to take things into another topic as an example.
- say you have two elderly adults living together in a small home. They produce dirty dishes, dirty laundry, and dirty floors at a rate which is easily attenuated by a maid coming in once a week to clean. The maid provides a service at a rate (once a week) that is sufficient for the job.
- now imagine if four grandkids come over for a week during summer; the rate of dirty dishes, laundry and floors becoming contaminated quicker will rise for sure. It may not be sufficient to have the maid come only once a week.
You have one of two choices, you can either increase the number of maids who come once a week, or you can have the maid come twice a week. Either of these would suffice for the higher "dirt rate". But OTOH, those higher cleaning rates are not necessary for the "normal" lifestyle of the adults living alone.
My point? If the rate of sump contamination is sufficiently controlled by lube X, it's not really necessary to use lube Y which may have "more" additives. If your OCI is a fixed value, and lube X has plenty of cleaning ability, then using lube Y (which has more potential) won't make a tangible difference in cleanliness; essentially that potential goes wasted. I'll make up values from thin air just to illustrate the example:
* if your engine experiences 10g of contamination every 10k miles, the rate of contamination is 1g/1k miles
* if the lube you chose has a cleaning agent capable of hold 15g of dirt, and you only run a 7k mile OCI, then you've got 8g of capacity that goes unused
* if you choose a different lube that has even more holding capacity (say the ability to hold 20g of dirt), and still only run a 7k mile OCI, then the unused capacity is now 13g.
Congratulations! If you spend more money for the "better" cleaning oil, but didn't use that capacity, you just wasted money.
Now, if you decided to lengthen the OCI out to 17k miles, the resulting 17g of dirt would overwhelm oil X, and therefor oil Y would be a good decision.
My point is that the topic of holding capacity of a lube is no different than that of an oil filter. If your product has sufficient capacity for the job, adding more capacity doesn't help; it simply goes wasted. You have to understand that "capacity" of any product has to be viewed in terms of the "rate" of exposure, relative to the total capacity of the product.
So while I do agree that some oils will hold contamination in greater quantity, that ONLY comes into play if the duration of the exposure exceeds the capacity of any one product and favors another.

Finally, it's true that BS does not directly measure oxidation, soot, etc. But what they provide is an "insolubles" count. That count is a visual reference of the relative opacity of the diluted sample. When we see values of .1 or .2 in a BS report, that indicates that the total insolubes (soot, sludge, oxidation) are very low; versus if the reading is .5 or .6 which would indicate a heavily soiled sample. I do agree that other means of measuring soot and oxidation individually are probably more accurate, but the insoluble count BS provides does have merit; it's not useless. Just like all the other topics of spectral analysis, the "insolubles" have to be understood in context.
 
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Let’s also not forget the effect of residual oil. If one were to perform a UOA 100 miles into an interval there would be considerable wear metals owing to the the contaminated nature of the oil that wasn’t removed during the change (10-20%?). All other reasons aside, this would contribute to higher “wear” rates in a short OCI.
Residual oil is certainly a topic of discussion. That likley has some effect in the calculation of wear rate in OCIs. However, the SAE study we speak of also was able to correlate the higher wear rates of shorter OCIs using component analysis (electron bombardment weight loss, IIRC); that method does not rely on a UOA, so the "residual" effect isn't nearly as germane to the topic at first glace.

I would agree that in UOA sampling, the effect of residual oil is a thing. Unfortunately we have little ability to discern how much that has an effect as a percentage of the overall reading. But given the separate method of wear measurement I mentioned above, I will say it's not nearly as large as some folks think. Is it present? Yes. Is it large enough to skew the result heavily? Probably not. It may be on a scale of perhaps 10%-15% of the total rate. This variation would be represented in the standard deviation of normality of samples.

So, if you OCI regularly at 3k miles, your Fe wear rate might be 3.0ppm/1k miles. Of that, perhaps .3ppm might be residual?
But if you OCI at 10k miles, your overall wear rate might come down to 1.2ppm/1k miles. Of that, the residual effect lessens by percentage; .12 per thouand miles. The longer you run the OCI, the less the residual has effect in the calculation. But it's not a majority factor by any means.

The SAE study showed that the initial load of fresh oil detergents strips away the TCB layers, so you end up with a condition where the metal-on-metal issue is more in play at start up. Until the hydrodynamic barrier is builtwill up with oil pressure, the "clean" metal parts have more direct contact. As the OCI matures, the TCB layers become thicker and more beneficial; they become a sacrificial barrier during start-up and low-rpm (low oil pressure) periods until the hydrodynamic oil barrier is in place with greater pressure. Additionally, there is actually a friction reduction that comes with the TCB; it's not just wear reduction. The portion of the study that focused on the valvetrain actually showed the TCB reduces running friction AND wear!

I would agree that residual oil may slightly affect the wear rate calculations, but it's not the majority of the contribution of data. We'll probably never know exactly how much the residual effect is, but it would be fair to estimate it below 20%. The electron bombardment method isn't subject to residual numerical influence, and that test method shows the TCB to be the main player in the wear rate results. And regadless of that residual effect, as long as it's inclusive in the samples, relative one sample to another, it's effect gets muted.

I encourage people to buy the study (2007-01-4133) and read it. It's factinating. You cannot just read the summary abstract and think you understand the whole topic.
 
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Soobs,

Thanks for posting your UOA! It’s a great report.

What oil did you use in the Highlander immediately before this run of ST?
And what oil went back into the crankcase?



And Soobs, don’t follow this advice, please. A 3k OCI on this engine is absurd.
I wouldn’t consider a 5k OCI, either.
Hey dkryan!

The previous oil was the same ST Advanced 0W-20 and the oil I used for this change was also the same. Also, this vehicle has only seen OE filters. In regards to the OCI the manual states 5,000 OCIs for “repeated trips less than 5 miles in temps below 32F or extensive idling and/or low speed driving for a long distance such as police, taxi, or door-to-door delivery.” Neither of those really apply to our driving. I think worst case for this kid hauler would be 7,500 OCIs and that does seem to line up with the average OCI Blackstone sees for this engine. Tbh with wear metals low, viscosity holding up, TBN good, and no contaminants I’m not concerned with a 10k OCI. I haven’t decided what I’ll do next, but will cross that bridge later.
 
UOA can not show varnish which can cause other problems like ring sticking or VVT problems
70% city driving is severe service according to Toyota and should follow the severe service of 5000 miles or 6 months
 
First, let's limit our conversation to healthy engines. Equipment that is badly ailing and/or abused with no regular maintenance will not really help this discussion; I exclude those from my comments below.
Even "regularly" maintained engines can show considerable varnish accumulation if the lube used wasn't up to the task or that particular engine is extremely hard on oil. We've seen that with the Honda 3.5L VCM engine for example.
It's true to say UOAs are "limited" in what they can see, but we have the ability to take samples and make an informed inference of the overall wear condition. But I disagree with you when you state they are "limited in value".
Please note I wasn't saying the UOA's were limited in value, rather, the wear metals are. There is a tendency on here for folks to run say a Pennzoil lube, see 12ppm of Fe, then run Supertech, see 8ppm of Fe and conclude that the Supertech has a superior wear rate, which isn't the purpose of the tool and those values are well within the noise limits of spectrography, in fact most comparisons that result on here between UOA's do. And that brings us into the topic of chelation, more aggressive chemistries and the like.
I agree completely with you in regard to the topic of esters and chelation. That's been seen quite easily in the GM 6.6L Dmax engines. They shed Cu like a dog sheds a fur in spring, when you introduce an ester-laden lube; that's because the oil cooler is a copper-plate design. However, you didn't also mention that the reaction of the metal to the ester will actualy subside over time as the metal normalizes to that chemistry. That normalization often takes many thousand of miles; often more than one or two OCIs. Which brings me to another point ... changing lube brands every OCI only compounds the issue. When we see folks trying Amsoil, then RP, then RL, and then continue down the oil-de-jour path every OCI, the engine metals never really get a chance to acclimate to the lube before the next is introduced.
But ... I would argue this ... how's that the fault of the UOA? How is that the fault of spectral analysis????
What that shows is a lack of understanding on the part of Joe Average regarding how his choices and actions can skew a test result. If you don't understand the benefits and limitations of a tool you are using, you're likley to misuse the tool, or misinterpret the results the tool provides. That is NOT a indictment of the tool; it's a clear display of ignorance upon the user. A UOA is only as good as the person using it, and frankly we have a lot of amateur hacks on this site grossly misutilizing and misinterpreting UOAs. But that's not the fault of spectral analysis now, is it?
Agreed, and that's part of what I was getting at with the comment on limited value as well. These two points run congruent.
To continue, I understand you comment regarding holding capacity of a lube, but that somewhat looks at the end of an equation and ignores the process unfolding. Just as engines shed metals at some rate, they also experience contamination at some rate. Sludge and silica don't just show up en-mass on day one; they accumlate over time. And the host oil starts out "fresh" with it's given load of anti-oxidants, anti-agglomerates, detergents, etc. Essentially, any oil starts out with 100% of it's ability, and then degrades. Yet the sump contamination starts out (near) zero, and escalates. So as long as the capacity of any one oil to deal with contamiation isn't overwhelmed, it's not really a a big deal to worry about how it fares relative to another lube. Let me show this as analogy; I think it helps to take things into another topic as an example.
- say you have two elderly adults living together in a small home. They produce dirty dishes, dirty laundry, and dirty floors at a rate which is easily attenuated by a maid coming in once a week to clean. The maid provides a service at a rate (once a week) that is sufficient for the job.
- now imagine if four grandkids come over for a week during summer; the rate of dirty dishes, laundry and floors becoming contaminated quicker will rise for sure. It may not be sufficient to have the maid come only once a week.
You have one of two choices, you can either increase the number of maids who come once a week, or you can have the maid come twice a week. Either of these would suffice for the higher "dirt rate". But OTOH, those higher cleaning rates are not necessary for the "normal" lifestyle of the adults living alone.
My point? If the rate of sump contamination is sufficiently controlled by lube X, it's not really necessary to use lube Y which may have "more" additives. If your OCI is a fixed value, and lube X has plenty of cleaning ability, then using lube Y (which has more potential) won't make a tangible difference in cleanliness; essentially that potential goes wasted. I'll make up values from thin air just to illustrate the example:
* if your engine experiences 10g of contamination every 10k miles, the rate of contamination is 1g/1k miles
* if the lube you chose has a cleaning agent capable of hold 15g of dirt, and you only run a 7k mile OCI, then you've got 8g of capacity that goes unused
* if you choose a different lube that has even more holding capacity (say the ability to hold 20g of dirt), and still only run a 7k mile OCI, then the unused capacity is now 13g.
Congratulations! If you spend more money for the "better" cleaning oil, but didn't use that capacity, you just wasted money.
My point is that holding capacity of a lube is no different than that of an oil filter. If your product has sufficient capacity for the job, adding more capacity simply goes wasted. You have to understand that "capacity" of any product has to be viewed in terms of the "rate" of exposure, relative to the total capacity of the product.
So while I do agree that some oils will hold contamination in greater quantity, that ONLY comes into play if the duration of the exposure exceeds the capacity of any one product and favors another.
All true, but we have a broad spectrum of engines out there, some of which are considerably harder on oil than others. The sludge-prone Toyota 4-cylinder for example with the inadequate piston oil drain holes, ring land varnish build-up would lead to massive oil consumption, same with the Saturn 1.9L engine. From what I recall, a more robust lubricant changed frequently could avoid this issue, but there's nothing from the OEM indicating that this was necessary. Yes, these are both manifestations of the same mechanical defect, but it highlights that certain engine or engine families can be hyper sensitive to varnish. Others of course can be extremely tolerant like the BMW I6's.

I specifically mentioned the example posted recently by @The Critic because this was an engine run on "reasonable" extended drain intervals (~15K miles apparently, according to the owner) with a premium extended drain lubricant, that experienced massive varnish build-up. @Trav also has a tremendous amount of experience with this particular engine and the OEM lubricant spec is simply wholly inadequate for how hard that particular engine is on oil. I would love to see some UOA's from this engine to see if we get even a hint of what is going on there in the report.
Finally, it's true that BS does not directly measure oxidation, soot, etc. But what they provide is an "insolubles" count. That count is a visual reference of the relative opacity of the diluted sample. When we see values of .1 or .2 in a BS report, that indicates that the total insolubes (soot, sludge, oxidation) are very low; versus if the reading is .5 or .6 which would indicate a heavily soiled sample. I do agree that other means of measuring soot and oxidation individually are probably more accurate, but the insoluble count BS provides does have merit; it's not useless. Just like all the other topics of spectral analysis, the "insolubles" have to be understood in context.
Yes, Blackstone provided limited data, not only on this front, but on fuel dilution as we've previously discussed. Unfortunately, most of the UOA's we have posted here are from Blackstone and are the ones that Joe Average isn't interpreting properly.
 
UOA can not show varnish which can cause other problems like ring sticking or VVT problems
70% city driving is severe service according to Toyota and should follow the severe service of 5000 miles or 6 months
I understand UOAs aren’t a complete picture; however I want to clarify what the manual actually states regarding operating conditions. For my year/make/model the manual doesn’t use the term “severe service.” The addn’l maintenance and reduced interval fluid changes fall under special operating conditions which are defined as:

1. Repeated trips of less than five miles in temps below 32F.

And/or

2. Extensive idling and/or low speed driving for a long distance such as police, taxi, or door-to-door delivery use.


While a good chunk of this vehicle’s daily commute is in a city the majority of it is neither of those defined conditions.
 
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Because most of those intervals are inadequate unless you want to sell it before 150K.
Suburban driving is Severe Service. I believe the car makers are using a very small window of vehicle use when they come up with these long oci"s. It's about marketing and pleasing the epaulet.
 
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