thin perhaps not as good as i thought

[CATERHAM]

Originally Posted By: Trav

Take you situation. You use the 20w but the gauges tell you you really need a heavier oil so you take his advice and go as "thick as necessary" because you already went as "thin as possible" and put a 30w in it.

You just voided your warranty because you are mandated to 20w and nothing else.
So i think Caterham should add a line to the like thin as possible thick as necessary.
Maybe and toss your warranty right out the window.

I've heard you're a decent mechanic (excluding any advice on motor oil of course) but that's one of your more rediculous arguments.
If one can't maintain adequate OP on the spec' oil grade during the warranty period the first thing one should do is return the car to the dealer to investigate; something is obviously wrong and it's not likely the oil's viscosity particularly if your oil temp's are not high.

But it is another good example of the value of oil gauges.

 

[demarpaint]

Originally Posted By: Volvohead


Many are watching.

 

[KrisZ]

Running whatever oil viscosity the manufacturer recommends is not a problem with me. I trust that the manufacturers did their homework to recommend a certain viscosity for all operating conditions. After all, US car market is the most important, even though not the biggest, in the world for a lot of car manufacturers and none of them would be willing to risk their position by not doing their homework for such a basic, but extremely important factor.

Having said that, the blind following that the thin oil gets recently is troublesome. Catheram stated many times that he will "thicken up" the oil during the OCI if it is necessary.

But people don't want to install OP gauges, they want a one size fits all, so they seem to "tune out" all the variables involved and just register that 0w20 is OK.
I think that what irks me the most.

 

[CATERHAM]

Originally Posted By: Volvohead
Originally Posted By: CATERHAM
So if you can maintain the required minimum OP on a 2.6cP 200 VI 0W-20 oil in your climate and with the way you operate your vehicle then that's the heaviest grade you need to run regardless of what oil grades are listed or recommended for that engine.


Ok, I guess we'll stop with the joking around for a little bit. Let's get more serious.

You continue to present what is a position contrary to conventional engineering and industry wisdom -- a decidedly rogue opinion:

0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended

Your words -- your opinion -- your thesis.

Since you present it as an expert, contrary to the industry mainstream, the burden is now on YOU to present your underlying evidence, just like any other adverse expert with a differing opinion.

In jurisprudential terms, it's called a Daubert hearing.

Present your engineering data and other expert evidence to support your opinion that: 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended

Just because you state something as a fact, does not make it evidence of it. Self-proving statements are not evidence.

Present the engineering and scientific evidence, laboratory data, field studies and other technical proof supporting your claim that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

Presenting evidence that a 20 weight oil effectively lubricates some engines is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended. It's evidence that a 20 weight oil effectively lubricates those engines only.

Stating that those who disagree with you don't understand "operational viscosity" or some other element of your theory is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

Stating that 0w-20 is recommended in certain engines or by some manufacturers is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

Presenting a UOA from an engine or two is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended. It is evidence of a UOA in those few engines.

Demanding that others present proof to the contrary is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

Declaring others' statements "strawmen" is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

Presenting your own external gauge measurements is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended. It's evidence of pressure and temperature at the gauges.

Stating that someone didn't quote you completely isn't evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

But just so that little red herring is disposed of, we'll repeat the unnecessary surplusage surrounding your contention:

So if you can maintain the required minimum OP on a 2.6cP 200 VI 0W-20 oil in your climate and with the way you operate your vehicle then that's the heaviest grade you need to run regardless of what oil grades are listed or recommended for that engine.

Qualifying your statement with conditions and caveats is not evidence that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended. It's setting up hypothetical variables to make your thesis workable -- under those variables alone.

You're advocating this statement.
You're advocating this statement as an apparent expert on the subject.
You're advocating this statement, contrary to other experts and designers who HAVE listed and recommended different oil grades.

So now YOU need to present the actual technical evidence supporting your opinion -- that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

Let us see all the abstracts, the technical studies, the fleet tests, the lab reports supporting that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended.

All of it.

The burden is on YOU, and no one else.

If you wish to behave and speak like an expert, then you have to back it up like one.

Many are watching.

I am surprised that you actually question the concept of operational viscosity which the reading on an OP gauge is a proxy for. An engine has no idea what grade of oil is in the sump just what the actual viscosity is at any moment and it is primarily a function of oil temperature. This is nothing new and no engineer disagrees with this basic concept.

In a few days I'll be posting the UOA of the 0W-20 ( HTHSV 2.6cP, 200V) oil out of my track car. The specified oil is a 5W-50 grade, for your entertainment value.

If you click on the link in the following thread it discusses the concept of operational viscosity at length:

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2685701&page=1

 

[cp3]

Originally Posted By: Trav

BTW he was right at it again last night. Guy has an 07 Honda with 87K on it spec for 5w20. The guy has Mobil 1 5w20 in it, no problem right? Wrong!
Quote:
If you already have the M1 5W-20 in your car I wouldn't dump it, it's just heavier than necessary. But for your next oil change I'd choose a 0W-20.
For long summer road trips the advantages of the high VI Toyota and Mazda oils are minimized, any 0W-20 would likely perform as well. But I would very much prefer M1 0W-20 and even PP 5W-20 over M1 5W-20 for summer use, it's just unnecessarily heavy.


https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2804931&page=1

The guy continues with this daily yet the fan club keeps supporting him and this insanity. Notice the little proviso just in case everything goes into the weeds after he just told the guy "it's just unnecessarily heavy".


I'm sorry, I don't understand where the insanity is in this quote.

 

[JOD]

Originally Posted By: demarpaint
Originally Posted By: JOD
Originally Posted By: demarpaint

I would like to have the option to make the oil viscosity decision myself, w/o running the risk of voiding a warranty in doing so. I think that's fair enough wouldn't you agree?


In your specific instance, where the manufacturer is providing you with a lifetime warranty on the engine? No, I don't agree. I think you should use what they specify and not worry about what they do in other countries. After all, they're the ones "assuming the risk", not you. If you wish to take advantage of that, you should play by their rules. I just don't understand how you feel you're somehow being harmed or limited on this deal?

BTW, do they offer that same lifetime warranty in other countries which have "more options"? No, they don't.



My warranty is no longer offered, but in effect. If they offered it in other parts of the world I honestly couldn't tell you. I was bringing out a point about how only the US has no choice in oil selection for a large part of vehicles sold here. Wasn't it you who uses an oil that is not spec'd for your vehicle? You must have had a reason for doing so?


yes, but this wasn't a matter of "inadequate U.S. recommendations". The world-wide recommendation was an A5-rated oil, a recommendation which many owners of these cars found to be suspect. So, you can't blame CAFE for this recommendation.

I wasn't asking the question, btw, I looked: they did not offer this warranty outside of the U.S. No, I don't think that's "proof" that world-wide recommendations are "sub-optimal", but the FACT is those recommendations are limited by their own set of limitations, one of which is a lack of wide-spread world-wide distribution of 20W oils. There's a guy on the Freestyle forum using 20W50 because it's the only name-brand oil to which he has ready access.

You win, I've officially been beaten into submission. The mfg of your car is offering you a lifetime warranty on your vehicle, so they're clearly standing by the recommendation--yet you're still looking for a reason to be slighted. I'm sorry, but I simply can't understand why, except that you're looking for a reason to be slighted. You haven't actually put forth any reason as to why you want to use a thicker oil, or how there's harm being done..just that you think it's wrong that you don't have that option, and it's the government's fault.

It doesn't seem that running the optimal lubricant for your car is really your goal, but rather being slighted by the government seems to be your real goal. As such, I don't think I really have much to add to the discussion.

 

[Shannow]

Originally Posted By: buster
Originally Posted By: JOD
Originally Posted By: HerrStig
I'm still waiting for a rational explanation of why oil reccomendations for the SAME car can vary by country.


Why, when it's been explained a million times? different operating conditions, limited distribution of 20W ois, consumer perceptions, longer specified drains, government regulations (some countries had lower limits of 3.5 hths until fairly recently).

I'm still waiting for a rational explanation as to why it matters to someone operating their car in the U.S.?



+1


Toyota can bring WHOLE CARS to Australia, and there's not enough camels to drag the oil around ?

ALL of which is imported ?

 

[Volvohead]

Originally Posted By: CATERHAM

I am surprised that you actually question the concept of operational viscosity which the reading on an OP gauge is a proxy for. An engine has no idea what grade of oil is in the sump just what the actual viscosity is at any moment and it is primarily a function of oil temperature. This is nothing new and no engineer disagrees with this basic concept.

In a few days I'll be posting the UOA of the 0W-20 ( HTHSV 2.6cP, 200V) oil out of my track car. The specified oil is a 5W-50 grade, for your entertainment value.

If you click on the link in the following thread it discusses the concept of operational viscosity at length:

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2685701&page=1


We have to leave shortly for holiday. So you have some more time to present whatever you wish.

But so far, you have presented the following to evidence your thesis that 0w-20 oil is . . . the heaviest grade you need to run regardless of what oil grades are listed or recommended:

1. Surprise that your self-declared statements about operational viscosity are being questioned, and a further self-declared statement that "no engineer disagrees with" your concept of operational viscosity;

2. A promise to present in future a single UOA from your personal vehicle; and

3. A link to a BITOG thread that references a Driven Racing Oil webpage titled "Choosing the Right Viscosity", your conversation with a "track buddy", and your chat with Lake Speed, Jr.

I am a fair individual. Rest assured, I will patiently and completely read any material you might present. I will not purchase third-party abstracts, so you will have to provide those in some fashion. And if you evidence your position, I'll be the first to note it.

But the burden to evidence your opinion remains on you.

 

[Shannow]

Originally Posted By: CATERHAM
Originally Posted By: Volvohead
Originally Posted By: Shannow
An engine has lots of stuff happening, bearings (which behave like bearings behave, and have significant difference between bulk oil and bearing operating temperatures), oil squirters (minimal temperature rises, and direct oil based on plain old viscosity and density, not HTHS), chain oilers and tensioners, et al.


You're getting at the root of it, Shannow.

Anyone who thinks they can Carnac the entire internal engine operating environment better than the manufacturer's design team did, with just a couple of fluid gauges tacked to the A pillar, is running with blinders on.

It's a very complex environment indeed.

Another strawman argument.
Shannow certainly does not adhere to the "as thick an oil a possible" doctrine and he runs a 5W-30 grade which is light by Ozzy standards considering what's available down there.
He's also on record stating in no uncertain terms that an OP gauge is an effective viscometer, useful for gauging the operational viscosity of oil in an engine.


If you read back, that quote was in response to refuting the temperature rise across bearings (simple laws of physics, oil gets hotter across bearings), as bulk oil temperature rise is diluted by the other stuff that goes on in an engine.

 

[Coprolite]

Volvohead,

Where does Caterham claim that 0w20 is the only oil needed?

Just by reading his signature your whole tirade is rendered comical.

 

[OVERKILL]

Originally Posted By: JOD
Originally Posted By: il_signore97
Originally Posted By: Shannow

An engine has lots of stuff happening, bearings (which behave like bearings behave, and have significant difference between bulk oil and bearing operating temperatures), oil squirters (minimal temperature rises, and direct oil based on plain old viscosity and density, not HTHS), chain oilers and tensioners, et al.



This is something I think we all forget from time to time. Thanks for posting the reminder

An engine is not just a bunch of hydrodynamic journal bearings. While we can use an oil pressure gauge to determine back pressure as a result of proper bearing operation, the OP gauge will not tell us the size of the oil film generated between the piston rings and the cylinder walls -- an equally important part of an IC engine.


That's certainly true. It's also been demonstrated that lighter weight viscosity oils provide thicker film mid-stroke at the top of the piston, and the reality this is probably more important in terms of wear.


I've had a pile of engines apart and those that were maintained, regardless of what oil they ran, didn't have bore wear. With Ford 302's, it was quite common to still have visible cross-hatching, no ring ridge and no measurable bore or piston wear. Often these engines were run on anything from 10w30 to 20w50. Anything in the HTHS range you cited earlier would have been scoffed at as being "water" by many of the owners of these engines.

Another glance over at the diesel land, even acknowledging that their bearing situation differs greatly from a gasser, if heavier oil was to cause wear in the cylinders, we would see this on tear-downs, but we don't.

So that being the case, I'm not sure how you've come to this conclusion? It certainly isn't backed my my experience. If anything, engine DESIGN plays a far greater role here in bore wear than if somebody is running 5w20 or 20w50.

 

[JOD]

Originally Posted By: Shannow



Toyota can bring WHOLE CARS to Australia, and there's not enough camels to drag the oil around ?

ALL of which is imported ?


Shannow, stop being ridiculous. No one said that Australia can't implement widespread distribution but that they haven't---because it's true! So please stop pretending this is some sort of insult. You live there--so you obviously know this. I spend 2 weeks a year there every other year and I've never seen a 20W oil on the shelves at Sprint Auto parts. I'm sure that you can "get it", but that's not "wide-spread distribution".

 

[MarkStock]

Originally Posted By: demarpaint
The 2004 Ford article you copied and pasted isn't cutting it.


For you, no. After all, your challenge to that was to ask me if I was there when they took fully loaded Expeditions on 15k ocis on synthetic blend a total of 250,000 miles in the deserts of Arizona and Nevada. And they tested the same oil on taxis in the Minnesota winter in stop and go conditions. Their conclusion: in some cases 5w20 performed better than 5w30.

Your rebuttal to that is "You weren't there" and "a 2004 article isn't cutting it". Seriously?

I happen to have a 2004 Ford so it's good enough for me.

You have a Jeep. I can understand a little why you might not trust them. It's not a company that I would buy a vehicle from. So I can somewhat relate to your lack of trust from an emotional, although rationally you're verging on paranoia IMHO.

Originally Posted By: demarpaint
Questions for you: Your MB gives you an oil choice, which oil do you use? Why? I'm pretty sure you were capable of making the choice and you didn't need MB or the Gub'ment to make it for you.


I have answered this question in previous posts, but especially for you, I will answer it again.

I use M1 0w40 which meets MB229.5 spec. I also have the choice of using GC 0w30 and other 30 and 40 weights that meet MB229.5 spec. But Mercedes recommend Mobil, so I go with that.

Why do I make the choice I do?

Primarily because the oil meets MB229.5 spec. And I do that because I believe the Mercedes engineers know what they are doing. So not only does it keep me in warranty, but it's what I believe is best for my vehicle.

Now, and this is important: The fact that their spec allows 30 or 40 weight oil is not really a choice in the sense you think it is a choice because the 229.5 spec calls for HTHSV of 3.5 or more. Most 30 weights have HTHSV of 3.0.

So while someone with less knowledge on how oil works might think I have a viscosity choice according to SAE measurements, I don't really have that much choice because the HTHS viscosity has to be a minimum of 3.5. And there are a bunch of other things in the 229.5 spec that mean very few oils meet the spec.

Indeed, readily available oil in the US that meets the spec are just M1 0w40 and GC 0w30.

So Mercedes engineers have certainly limited my choice more than CAFE has limited yours. And I'm not capable of making a choice beyond what they recommend as I don't know more than Mercedes. Just as I suspect you don't know more than Jeep. They have tested Mercedes for decades under operating conditions they expect to see in real use and have specified a very specific set of oil requirements that work for their engines.

 

[JOD]

I didn't reach that conclusion, guys who've actually measured oil films mid-stroke, using different viscosity oils, reached that conclusion:

"Piston Ring Oil Film Thickness - The Effect of Viscosity”, S.L. Moore, SAE 850439

The chart on figure 20 available here details the results.

Your experience hardly disproves that? It simply shows that the oil film from the viscosity used was sufficient--no more, no less. If you had torn down the exact same engine using a thinner oil and had a different result, well then you'd have something. As they say, "how did the control group perform"!

BTW, I apologize to the dude who was offended by people posting source links, but since you asked and all...

 

[OVERKILL]

Originally Posted By: Clevy

Explanations like this are exactly why I bought a mechanical op gauge and an oil temp gauge. Because it makes sense.
I understand dermapaints point in wanting to have a choice and not being held hostage by a warantee agreement.
Caterham takes the time to make a statement,and qualify it with a sensible explanation.
I've got boatloads of oil that I now know is to thick and I bought 6 jugs of pp 5w-20 to cut it all so it isn't wasted money on my part.
Yes Europe specs different oil but perhaps it's due to old habits dying hard,not because thicker is ideal.
I'm no expert however I am sensible,and when an explanation makes sense there is no point in arguing.
Thank you caterham for your wonderful explanations. I have learned much from you.
Old habits die hard,and perhaps I'm still on the fence,but I'm leaning a different way now.


Operating conditions, as I mentioned earlier, are different in Europe. At 150Mph on the Autobahn, my oil temp is going to be a heck of a lot higher than yours putting around on i-whatever at 70mph.

Believe it or not, the engineers who design these engines actually test them under a variety of operating conditions and then spec them for a lubricant (or lubricants) that will provide adequate protection under those conditions. They don't just slap on oil pressure and oil temperature gauges and go to town. They do controlled testing with tear-downs to determine what works and what doesn't. Some of these tests are extreme (Ford's Ecoboost test, the Porsche Nurburgring test....etc) but their purpose is to try and break things so that they can figure out how to make it so that things don't break under that usage profile.

Power density is a key component of what defines and engine's oil temperature operating range. Higher power density engines will heat the oil further. Often a combination of increased sump capacity, oil coolers and heavier oils are used to deal with this phenomena.

And every one of these things has a drawback.
-Heavier oil causes increased drag while heating up and can cause an engine to be sluggish
-Oil coolers, if not thermostatically controlled, will cause the oil to take longer to heat and thin, prolonging the time the lubricant is excessively heavy for the application
-Increased sump size again increases the amount of time taken for the lubricant to warm up, but it also acts as a heat sink and a larger sump allows for a thinner lubricant to be used, all things considered, as it will keep overall oil temperature lower.

This is also why oils like GC, M1 0w40....etc exist. They are relatively "heavy" with their higher HTHS values, but offer exceptional cold temperature performance compared to the 5w40, 10w40 and 15w40 lubricants they displaced.

Ford's sheer-happy 5w50 is another example of an oil designed to perform in a similar manner. Heavy enough to provide adequate protection for the BOSS 302 and Shelby engines under track-use conditions, whilst still being thin enough to function properly in daily driver use.

 

[demarpaint]

Originally Posted By: JOD
Originally Posted By: demarpaint
Originally Posted By: JOD
Originally Posted By: demarpaint

I would like to have the option to make the oil viscosity decision myself, w/o running the risk of voiding a warranty in doing so. I think that's fair enough wouldn't you agree?


In your specific instance, where the manufacturer is providing you with a lifetime warranty on the engine? No, I don't agree. I think you should use what they specify and not worry about what they do in other countries. After all, they're the ones "assuming the risk", not you. If you wish to take advantage of that, you should play by their rules. I just don't understand how you feel you're somehow being harmed or limited on this deal?

BTW, do they offer that same lifetime warranty in other countries which have "more options"? No, they don't.



My warranty is no longer offered, but in effect. If they offered it in other parts of the world I honestly couldn't tell you. I was bringing out a point about how only the US has no choice in oil selection for a large part of vehicles sold here. Wasn't it you who uses an oil that is not spec'd for your vehicle? You must have had a reason for doing so?


yes, but this wasn't a matter of "inadequate U.S. recommendations". The world-wide recommendation was an A5-rated oil, a recommendation which many owners of these cars found to be suspect. So, you can't blame CAFE for this recommendation.

I wasn't asking the question, btw, I looked: they did not offer this warranty outside of the U.S. No, I don't think that's "proof" that world-wide recommendations are "sub-optimal", but the FACT is those recommendations are limited by their own set of limitations, one of which is a lack of wide-spread world-wide distribution of 20W oils. There's a guy on the Freestyle forum using 20W50 because it's the only name-brand oil to which he has ready access.

You win, I've officially been beaten into submission. The mfg of your car is offering you a lifetime warranty on your vehicle, so they're clearly standing by the recommendation--yet you're still looking for a reason to be slighted. I'm sorry, but I simply can't understand why, except that you're looking for a reason to be slighted. You haven't actually put forth any reason as to why you want to use a thicker oil, or how there's harm being done..just that you think it's wrong that you don't have that option, and it's the government's fault.

It doesn't seem that running the optimal lubricant for your car is really your goal, but rather being slighted by the government seems to be your real goal. As such, I don't think I really have much to add to the discussion.


Putting words in my mouth now. I guess that's all you've got, I guess I did win then. I didn't know this was a contest though.

 

[demarpaint]

Originally Posted By: MarkStock
Originally Posted By: demarpaint
The 2004 Ford article you copied and pasted isn't cutting it.


For you, no. After all, your challenge to that was to ask me if I was there when they took fully loaded Expeditions on 15k ocis on synthetic blend a total of 250,000 miles in the deserts of Arizona and Nevada. And they tested the same oil on taxis in the Minnesota winter in stop and go conditions. Their conclusion: in some cases 5w20 performed better than 5w30.

Your rebuttal to that is "You weren't there" and "a 2004 article isn't cutting it". Seriously?

I happen to have a 2004 Ford so it's good enough for me.

You have a Jeep. I can understand a little why you might not trust them. It's not a company that I would buy a vehicle from. So I can somewhat relate to your lack of trust from an emotional, although rationally you're verging on paranoia IMHO.

Originally Posted By: demarpaint
Questions for you: Your MB gives you an oil choice, which oil do you use? Why? I'm pretty sure you were capable of making the choice and you didn't need MB or the Gub'ment to make it for you.


I have answered this question in previous posts, but especially for you, I will answer it again.

I use M1 0w40 which meets MB229.5 spec. I also have the choice of using GC 0w30 and other 30 and 40 weights that meet MB229.5 spec. But Mercedes recommend Mobil, so I go with that.

Why do I make the choice I do?

Primarily because the oil meets MB229.5 spec. And I do that because I believe the Mercedes engineers know what they are doing. So not only does it keep me in warranty, but it's what I believe is best for my vehicle.

Now, and this is important: The fact that their spec allows 30 or 40 weight oil is not really a choice in the sense you think it is a choice because the 229.5 spec calls for HTHSV of 3.5 or more. Most 30 weights have HTHSV of 3.0.

So while someone with less knowledge on how oil works might think I have a viscosity choice according to SAE measurements, I don't really have that much choice because the HTHS viscosity has to be a minimum of 3.5. And there are a bunch of other things in the 229.5 spec that mean very few oils meet the spec.

Indeed, readily available oil in the US that meets the spec are just M1 0w40 and GC 0w30.

So Mercedes engineers have certainly limited my choice more than CAFE has limited yours. And I'm not capable of making a choice beyond what they recommend as I don't know more than Mercedes. Just as I suspect you don't know more than Jeep. They have tested Mercedes for decades under operating conditions they expect to see in real use and have specified a very specific set of oil requirements that work for their engines.


Wow you're a real auto expert, at least from what you've been reading. You believe everything you read too. Why so much difficulty changing spark plugs?

Explain to me how an article from 2004 that says all Fords will use 5W20, which is certainly not the case is valid in 2012? Maybe Ford realized 5W20 just doesn't cut it in all applications.

 

[OVERKILL]

Originally Posted By: JOD
I didn't reach that conclusion, guys who've actually measured oil films mid-stroke, using different viscosity oils, reached that conclusion:

"Piston Ring Oil Film Thickness - The Effect of Viscosity”, S.L. Moore, SAE 850439

The chart on figure 20 available here details the results.

Your experience hardly disproves that? It simply shows that the oil film from the viscosity used was sufficient--no more, no less. If you had torn down the exact same engine using a thinner oil and had a different result, well then you'd have something. As they say, "how did the control group perform"!

BTW, I apologize to the dude who was offended by people posting source links, but since you asked and all...






I assume you mean this remark:

Quote:
The assumption that lower viscosity lubricants automatically give rise to thinner oil films in
key lubricated contacts in a gasoline engine is also open to question, particularly in the case
of piston rings. Laser Induced Fluorescence measurements have found that, in a Nissan
gasoline engine, the mid-stroke top ring oil film thickness was greater for an SAE-5W/20
lubricant than it was for an SAE-15W/40 lubricant. These effects were also observed in our
laboratory for monograde lubricants. Similar effects have been observed by S.L. Moore of
BP36. Figure 20 illustrates the observations. A qualitative explanation of such an effect
could be as follows : There are two routes by which lubricant reaches the top piston ring.
Route #1 (the “conventional” route) is that oil is left on the liner by the passage of the
preceding ring. The higher the oil viscosity, the larger will be the oil film thickness left on
the liner. Route #2 involves oil being transported to the top piston ring via the ring gaps
(such flows have been observed by Nakashima et al37), and this is thought to favour lower
viscosity lubricants. The precise balance between oil transported by the two routes will
determine whether the oil film thickness under the top ring is greater for a lower viscosity
oil or not.


I see no mention of a conclusion about wear, simply that the film thickness was slightly higher (which makes sense, thinner oil is going to work its way up the piston in greater volume than thicker oil).

The person who appears to have made the wear correlation is you, and my argument here is simply that I have not observed that in application.

 

[Trav]

Quote:

I'm sorry, I don't understand where the insanity is in this quote.

The guy has an 07 Honda it is spec for 5w20 and thats what ihe is running, Mobil 1 to boot which is considered by many a top shelf oil.
They back spec the engine to 0w20 but that doesn't mean 0w20 is preferred or that 5w20 is of the menu or too heavy it simply means it can use it.

Not only did he recommend moving to 0w20 which is okay but has to toss in that Mobil 1 5w20 is too heavy in the summer.
Come on now the oil being used is spec for this engine (AFAIK Honda doesn't put 5w20 with this HTHS in the owners manual) and even a 5w30 wouldn't be too heavy in summer.
If someone suggested he use 5w30 the fan club would go bonkers If you don't see the problem here there is nothing else i can say.

 

[edhackett]

Originally Posted By: JOD

Sure they do. But no one has been able to demonstrate that the recommendations in the U.S. are not suitable, so why are we worried about what they do elsewhere? Other countries have their own limitations which factor into their oil recommendations. Why is it the concern of someone who lives here?


Their recommendations are different. Why? The main reason for being here is to learn something, isn't it?

Learn something about tribology, chemistry, physics, mechanical design, business, etc. Learn about the political and marketing forces at play with the various recommendations. Learn about issues specific to your make and model of car, and your specific use of that vehicle. Use that knowledge to think for yourself. Is the vehicle manufacturer's recommendation sound? For the vast majority of people the conclusion will be that it is.

There are exceptions, one of my personal vehicles being an example. I knew from research that the recommendation in the owner's manual was not optimal. I chose an oil and OCI counter to the manual. Two years later the manufacturer changed the recommended oil and interval to be more in line with my choices. I went a step further in choosing a class of oil that has an additive package more suited to addressing the specific issue with this engine.

Be a good sheep, follow the manual, mommy knows best.

Answers along the lines above don't serve to increase the knowledge of either the one asking or answering.

Ed