Iron PPM in Honda/Toyota Engines - why low?

[lubricatosaurus]

Anybody know why many Honda and Toyota engines have so little Fe iron ppm on UOA's?
They usually beat other makes by a factor of 2. Here is just one example:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3864940/Re:_PU_5w30,_10,700_miles,_200#Post3864940

I can't tell they are constructed all that much differently than other makes.

Is it surface hardening? More DLC coatings? This has been going on for years and I'm wondering what fundamental engine differences are in Toyota/Honda engines that other engines don't have.

 

[aquariuscsm]

I'm guessing better metallurgy,more precise machining,and higher quality internals.

 

[lubricatosaurus]

Originally Posted By: aquariuscsm
I'm guessing better metallurgy,more precise machining,and higher quality internals.

Yet I've never thought BMW and Mercedes, to name a couple, were lacking in high-tech either. I find it hard to believe Honda and Toyota are really that much better.

 

[OneEyeJack]

Quality? Less iron in the engine? For the price, a better car.

 

[OVERKILL]

No idea, but it really seems to have no impact on longevity so.....

It isn't like the GM LSx engines tossing out much higher wear metals don't last.

 

[Jetronic]

more cilinders = more area where you could have wear so a smaller engine will likely show less.

more oil in the sump = less PPM for the same amount of wear materials

load of the engine is also important: high output engines load the piston assembly more (turbocharging, high static or dynamic compression)

And direct injection vs port injection will make a difference aswell.

and most importantly: the driver... in case of the link you posted " my mother's 2004 Accord V6"

 

[lubricatosaurus]

Originally Posted By: Jetronic
more cilinders = more area where you could have wear so a smaller engine will likely show less.

more oil in the sump = less PPM for the same amount of wear materials

load of the engine is also important: high output engines load the piston assembly more (turbocharging, high static or dynamic compression)

And direct injection vs port injection will make a difference aswell.

and most importantly: the driver... in case of the link you posted " my mother's 2004 Accord V6"


The only point of yours that might be right is the last one, the driving styles tend to be softer in Toyotas and Hondas, 'cuz its what decent people drive. LOL

More cylinders, well my example was a v6 with floppy timing chains, a valve train that makes the space shuttle seem simple, iron cylinder liners everywhere, etc. If you compare 4-cylinders out there (similar surface area), Honda and Toyota often win by a margin. And the output of Honda engines and Toyota ones is high enough.

This one has me puzzled. Could be there is something different in material selection, exacting metallurgical techniques, machining specs, etc. After all these years you'd think others might have caught up.

 

[Jetronic]

VW diesels have higher metal in UOA compared to VM aswell. but it's not like those engines don't last...

different materials is possible, japanese engines usually don't respond well to gas conversions, though it's valves and valve seats that's the issue. but maybe the different materials are used in liners/rings/cams aswell

 

[SLATRON]

Originally Posted By: OVERKILL
No idea, but it really seems to have no impact on longevity so.....

It isn't like the GM LSx engines tossing out much higher wear metals don't last.


+1 exactly. Deciding that uoa fe ppm is important, why? That's the question to be answered.

 

[OVERKILL]

Originally Posted By: lubricatosaurus
After all these years you'd think others might have caught up.


Caught up to what? This implies there is a problem to be fixed, I don't believe that to be the case. Each engine (and engine family) has its own "signature" in terms of wear metals. It is anomalies in that signature that show up during trended oil analysis that indicate a potential issue, not the numbers by themselves.

I cite the 1.2 million Kilometre tear-down analysis performed by member Doug Hillary with an Fe condemnation limit of 100ppm to trigger an OCI as a reference here. Visible cross-hatching still in the liners, bearings measuring "as new".....etc.

 

[CBR.worm]

Do they use nicasil or somethings similar in the bores?

 

[lubricatosaurus]

Originally Posted By: CBR.worm
Do they use nicasil or somethings similar in the bores?

Possibly some kind of surface coating on crankshaft journals, cam lobes/followers, cylinder wall coating, something physical to account for low levels of iron shed. Sounds reasonable.

Originally Posted By: OVERKILL
Each engine (and engine family) has its own "signature" in terms of wear metals. It is anomalies in that signature that show up during trended oil analysis that indicate a potential issue, not the numbers by themselves.

It would be absurd to think of the cause of the low iron PPM being like an X-File case or something of supernatural origin. Saying its "signature" is like simply repeating the question, not an answer. I'll let others philosophize all day about whether more iron in the oil is good or not.

 

[Jetronic]

I'd like to know what the manufacturer's condemnation level is for wear metals, but they'll never divulge this for passenger car engines.

 

[Leonardo629]

Since most wear occurs during cold start, maybe Honda simply implemented a more gentle cold start process.

Honda K-series engines have cast iron sleeves, so FE level does seem low, and I don't know why.

 

[OVERKILL]

Originally Posted By: lubricatosaurus

It would be absurd to think of the cause of the low iron PPM being like an X-File case or something of supernatural origin.


Nobody said it was supernatural. The number of iron and steel parts, their metallurgy, how they interface as well as what particle size any wear experienced by those components makes (because a UOA samples only a very narrow range of particle sizes)...etc are all contributing factors.

Originally Posted By: lubricatosaurus
Saying its "signature" is like simply repeating the question, not an answer.


Signature is indeed a correct term for when evaluating normalcy relative to a particular engine family. There's some good reading on the topic of UOA's on the main page of the site BTW:

http://www.bobistheoilguy.com/used-oil-analysis/

Quote:
Secondly, it is easy to assume that by carrying out a UOA you will be able to determine how quickly the engine is wearing out. As well, if you change lubricant Brands you will be able to compare the wear metal uptake results and then make a balanced best lubricant choice to make your engine last longer.

Sadly that logic is seriously flawed.


http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/

Quote:
It is in fact true to say that when you change oil frequently the UOA will exhibit a higher Fe wear metal count. There are two reasonable explanations to this phenomenon of elevated wear metals shortly after an OCI; residual oil and tribo-chemical interaction. When you change oil, no matter how much you “drip-drip-drip” the oil into the catch basin, there is always a moderate amount left in the engine. Ryan Stark of Blackstone estimates up to 20% of the old oil remains, more or less, depending upon the unique traits of each piece of equipment. So, when you begin your new OCI, you really are not starting at zero ppm. Additionally, there is indication that wear is elevated after each OCI because of chemical reactions of fresh additive packages. This claim is supported via an SAE study done by Ford and Conoco (ref #1) that surmised this very phenomenon, and additionally refers to a former study of the same conclusion predating it.


Quote:
Instead of speaking to wear rates, I’m going to focus on condemnation limits. Detroit Diesel does indeed publish condemnation levels for the wear metal content of the UOAs (ref #4). They have no limit for Al and Cr, but they do limit Fe at 150 ppm, Cu at 30 ppm and Pb at 30 ppm. It is interesting to note that of 511 total samples, none were over the 150 ppm Fe limit. There were two samples of Cu over 30 ppm; one at 33 ppm and one at 128 ppm. There were four samples of Pb over 30 ppm. Two were only 31ppm but technically over the limit. One Pb was at 43 ppm and one at 173 ppm. There were only 6 unique samples of 511 that were over the established condemnation limits, and yet look how low the averages and rates are. Even at 16k mile OCIs, people change the oil in this engine far too often.


Quote:
UOAs are great tools, but you must know how to properly manipulate the data and interpret the results. You must know not just the averages, but also if there are any abnormalities embedded in those averages and how large the standard deviation is. With all that in mind, you can then use the UOA as a tool in either micro or macro analysis, to see how well your equipment performs with respect to itself, and to others like it.


Each engine has its own "signature"; its own "normal" wear rate. The purpose of UOA's is primarily to determine lubricant health (fitness for continued use) and to watch for any deviations from what is "normal" for that engine.

You cannot simply look at a UOA for a Toyota 4-banger and a UOA for an LS1 and assume that because the Toyota has lower Fe that it is going to last longer or that the higher Fe in the LS1 is a "problem" that needs to be "fixed". Once you've established a trend for a particular engine, you then know what is "normal" for that engine; what that engine's "signature" is. Just like you can't compare UOA's on different oils to determine wear rates, you can't cross compare engine families because the numbers are unique to each family/model.

To determine actual wear one needs to perform tear-downs and do measurements. This is what the OEM's do to determine lubricant performance.

Now Dave does touch on engines with abnormally high wear trends; that is what is "normal" for this engine, what its "signature" is, indicate much higher wear rates than other, more modern engines. His example is the venerable SBC which he classifies as "poor wearing" due its signature wear rate being much higher than engines with more modern designs. Now of course everybody and their grandfather has a story about some SBC that lived 1/2 a million miles and outlived the truck it was fitted to so how significant is this factoid of "poor wear"? I don't know. Perhaps these are primarily flat tappet engines which would by design shed more iron than a roller or OHC engine

 

[OVERKILL]

Originally Posted By: lubricatosaurus

Possibly some kind of surface coating on crankshaft journals, cam lobes/followers, cylinder wall coating, something physical to account for low levels of iron shed. Sounds reasonable.


Overhead cam engines with either cam over bucket or roller followers will shed less iron than a pushrod flat tappet engine. A roller pushrod engine is similar in this respect.

Very few engines use alternative liner/bore coatings with the main culprits being the Germans (BMW for example) with Nikasil and Alumasil instead of steel liners. The rings however are still ferrous.

Most engines produced in the last 20 years have coated piston skirts, which are designed to reduce friction and ward off scuffing.

There's no surface coating on the crankshaft journals, these don't generally appreciate any wear. The bearings are much softer material and will be sacrificed long before material is lost from the crank.

Nothing else has a surface coating, however cylinder wall finish is something that has been played around with a fair bit. Camshaft lobes are generally hardened.

 

[lubricatosaurus]

OVERKILL, you keep talking about "signature" this and that. Granted that is the assumption my question has already made. The entire concept is predicated on "signature" as a given. In this question, am asking what causes the differences. I'm asking what is the physical difference that produces low iron in Honda-Toy engines.

Edit: I just saw your engine summary posting above. Everything you said is present in about every make of engine out there, including Honda-Toy engines, nothing different there.

I appreciate your replies, but I'm hoping someone has some special insight into what Honda-Toyota is doing to get low iron ppms. It is a tough question I know. It would take someone familiar with engineering tricks they use.

 

[Clevy]

Originally Posted By: lubricatosaurus
OVERKILL, you keep talking about "signature" this and that. Granted that is the assumption my question has already made. The entire concept is predicated on "signature" as a given. In this question, am asking what causes the differences. I'm asking what is the physical difference that produces low iron in Honda-Toy engines.

Edit: I just saw your engine summary posting above. Everything you said is present in about every make of engine out there, including Honda-Toy engines, nothing different there.
I appreciate your replies, but I'm hoping someone has some special insight into what Honda-Toyota is doing to get low iron ppms. It is a tough question I know. It would take someone familiar with engineering tricks they use.


There aren't any tricks. The typical Honda owner is a conservative easy driver (boy racer exempt) so typically the engines aren't stressed hard and tend to be well maintained.
Overkill has more than answered the question. There isn't any magic involved. It's the typical demographic of the owner and the fact that the sumps are medium sized for small displacement engines.
Honda is very specific about leaving the oil in for the entire first interval which contains high levels of moly and anti-wear agents from the assembly line which might be a factor,a small one anyways.
Look at the vehicles as well. They tend to be light,which means the engine isn't working very hard and the driver demographic is also a consideration.
In the end whether an engine sheds lots of metal or not doesn't affect the engines durability or lifespan.
As overkill already made clear once wear trends are developed and the specific engines "signature" is established as long as these norms don't deviate much the engine,regardless of make tends to outlast the body it's installed in.
It's not voodoo or magic and to be honest wear metals shed in the oil doesn't means much

 

[zeng]

Originally Posted By: lubricatosaurus
I appreciate your replies, but I'm hoping someone has some special insight into what Honda-Toyota is doing to get low iron ppms. It is a tough question I know. It would take someone familiar with engineering tricks they use.



Engineering tricks carried out on their finished products , besides knowing it , consistently in terms of quality control ......... anybody can elaborate ? I would love to know too , with certainty .

Toyota used to be world No.1 , not by 'signature' I suppose.

 

[Clevy]

There aren't any tricks. This question has been answered with certainty. Look above.
It's not voodoo or magic it's a combination of demographics,metallurgy and duty cycle. Nothing more.
And low wear metals doesn't mean much. A 30 dollar used oil analysis has only a narrow scope of what it can see. It's possible there are more metals in the oil that just aren't seen with a typical used oil analysis.
Low wear metals in no way equals low wear. It's not that simple sadly.
I'm sorry if the answers given are more than you care to absorb and are looking for some kind of special answer that doesn't exist.
The reality is the vehicles that are being referred to are cheap mass market items that are in no way special and the truth is of it could be done cheaper it would be. The techniques used are used because they are cost effective,not because it means longer engine life.
An engine is the sum of it s parts. Roller cams,rockers etc contribute to less wear metals,as does light spring rates.
These aren't race engines. They aren't high stress. They are a simple commute type cheap to build for the mass market
And that's it.
Each engine has its own wear signature that is determined by the data trends. If there is an anomaly in these trends one can infer there is a problem.
That's it.