What really makes an oil a good oil?

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I see that many people are currently worried about additive levels being lowered (supposedly) in CK-4 oils, but what does that really mean for us in the real world? Are the additives the only thing we should really be worried about or is the base stock much more important for a reduction in wear. We all get caught up in comparing zinc, phosphate, boron, and moly numbers, but unless we are chemists, what the [censored] do we actually know?

What really makes an oil a good oil concerning diesels?
 
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One of the best questions I ever saw posted in here.
Agree, everyone caught up in the limited scope of what an oil is tested for and why lately I have been of the mindset of whatever the API rating the manufacturer calls for is the best bet.

I personally, right or wrong, think film strength should be as important or more important. Im a little bit of a believer it RATS oil tests. (you can google rats test) trying not to hijack your questions because they are very valid.
Anyway, I cant answer your question and look forward to others, though I most likely will disagree if it goes much beyond whatever API grade the manufacturer call for ... :eek:) as I dont see tests backing up statements.
 
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Originally Posted By: alarmguy
I personally, right or wrong, think film strength should be as important or more important. Im a little bit of a believer it RATS oil tests. (you can google rats test) trying not to hijack your questions because they are very valid.

The problem is that even if you are correct about film strength being important, Rat's test is unable to distinguish between any of the oils tested. When his results are presented properly in accordance with the ASTM procedure, all oils test the same. So it is impossible to state that any one oil tests better or worse than any of the others.
 
Originally Posted By: kschachn
Originally Posted By: alarmguy
I personally, right or wrong, think film strength should be as important or more important. Im a little bit of a believer it RATS oil tests. (you can google rats test) trying not to hijack your questions because they are very valid.

The problem is that even if you are correct about film strength being important, Rat's test is unable to distinguish between any of the oils tested. When his results are presented properly in accordance with the ASTM procedure, all oils test the same. So it is impossible to state that any one oil tests better or worse than any of the others.


I expect this has been the case for many years now but the marketing hype will continue.
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me too, but I also believe in bypass filtration to get all of that fine particulate matter out of the oil (RAT doesn't), as it acts like lapping compound, IMHO.
 
Originally Posted By: Invasivore
I see that many people are currently worried about additive levels being lowered (supposedly) in CK-4 oils, but what does that really mean for us in the real world? Are the additives the only thing we should really be worried about or is the base stock much more important for a reduction in wear. We all get caught up in comparing zinc, phosphate, boron, and moly numbers, but unless we are chemists, what the [censored] do we actually know?

What really makes an oil a good oil concerning diesels?


I think your point is valid. I think MolaKule may be the only poster who meets the criteria. Even then, scientists don't all agree on the best approaches to additive packages. Compare the Ca/Mg approaches of Mobil Delvac vs Delo 400 SDE. You'll see that they both meet the standards but, in very different ways. Unless they can provide you (or you're willing to conduct) a well designed research project, recommendations are based on personal preference or anecdotal data. That's fine. People should pay for what they believe is best or, provides the best value for the money.

So, what makes an oil a good oil concerning diesels? Ask if it meets the current standards and if your vehicle manufacturer approves it and then do your homework and decide what you have confidence in. Call it and educated [censored] shoot ;-)
 
I went for the oil with runs on the board. Shell Rimula/Rotella in my case based on Special $ price at the the time helped (50% off) and old truckies and engine rebuilders I know swore by it.

Caltex/Chevron Delo. Mobil Delvac. all oils with >millions of miles on the board. Just choose the spec that suits your app. Oil test and monitor if you like, depending on your situation. Or just change at factory spec and sleep well at night.
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Do that and the engine will be the last good thing left after all else fails around it!
 
Originally Posted By: ozdrrider
I went for the oil with runs on the board. Shell Rimula/Rotella in my case based on Special $ price at the the time helped (50% off) and old truckies and engine rebuilders I know swore by it.

When I worked in the mines in outback Australia. We used Shell Rimula in everything.

One of the old diesel fitters gave up his old trade and became camp cook for the mines. His food was terrible, and we all reckoned he couldn't get his head around using vegetable oil for cooking and still used Shell Rimula. I don't know his real name, everybody called him Oil-Can-Harry.
 
Engines are particular. I have real good luck with Delo 400 in small block Fords. Even with over 200,000 on the clock, they start quiet and run well. Pass SMOG testing w/o a hitch. Not so on Rotella T-6 ... And they rattle like crazy on Mobil1 ...

Chebies, not so much. Small block Mopars are easy on oil, so it does not make a lot of difference.

My Saab requires synthetic because of a design issue. The CAT is adjacent to the pan at the oil pump pick-up location. Let it idle in traffic much and it'll coke up the pick-up and starve the engine for oil. So it gets synthetic.

Point being "best oil" is application dependent. Listen the the engine, it'll tell you want it wants. Haunt the web sites for your particular car/truck and learn from other why something works better in one application.

Got a AA Fuel Digger (?), I'll bet you will be running Redline just for the ability to absorb ridiculous amounts of un-burned fuel and keep the parts lubed'ish.

Running an air cooled bike in the desert, I'll bet Motul 300V will be your go-to oil
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They all seem to me to have weakness and strengths. It's hard to say what the best is. I look at the base oil used first although that doesn't matter to those who know what they're talking about.
 
Again I ask what M1 - was it a 40 or 50? HDEO? You know HDEO competition is the closest group of oils there is - but T6 is 12% NOACK, yawn on HTHS, and that's poor for "synthetic' so when you question others for being "synthetic " you treat T6 (to use your words) like a nectar. The Delo & Delvac you use is better than T6 in any parameter that matters ... they are all doing coking tests - sos on that
 
The last M1 I tried was 10W-30 from Costco. Went in the Beemer and then the Saab when the Beemer was sold and the Saab replaced it. Came out of the Saab in a week at less than 500 miles because of start-up noise. Went into the Bronco as it was nearly new oil. Bronco hated it. Actually heard light rod knocks on cold start. That was the last try for me. Came out of the Bronco and was recycled ...

T6 is not magic oil. But it's OK for a lot of applications. I'd take JD 50+ over T6 any day if I could get it easily and as cheaply ... The reason I mention T6 a fair amount it it seems it will fit the application and lots of others here are OK with it. Sort of like the anti-M1 oil. It's on the Allison list, so I know it's good enough. It's not like I'm advocating Golden Spectro or something ...

Have new (to me) truck with about 88K on a 351W. When it's time for a change. I'll give M1 another try. I think I still have two jugs. Motor is tight enough it should not matter. But I'll predict that by 150K, it will start to be noisy on cold start on M1if I use it that long ...

The Delo applications for me have been moving into the 15W-30 SD that I now have plenty of. But I'll use up my stash of other stuff like BMW brand 5W-30 LL (I got it free) and some Castrol RS I got at the same time. Both are "true" EU synthetics. I have some QSAD 10W-30 to use up too. Since the 1970 C-20 is sold, I dunno what that's going into ...

Fall is here and it's time to change many vehicles. I'll have to figure out my plan of attack. I'm sure my remaining M1 will go into something before Christmas ... The goal is to get down to 2 oils for most stuff. Something lighter and a xxW-40 for where it's needed ... I'll store 6~10 gallons of each at a whack. I need the current qt(s) shelf space for other stuff like 2-stroke oil ...
 
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Originally Posted By: kschachn
Originally Posted By: alarmguy
I personally, right or wrong, think film strength should be as important or more important. Im a little bit of a believer it RATS oil tests. (you can google rats test) trying not to hijack your questions because they are very valid.

The problem is that even if you are correct about film strength being important, Rat's test is unable to distinguish between any of the oils tested. When his results are presented properly in accordance with the ASTM procedure, all oils test the same. So it is impossible to state that any one oil tests better or worse than any of the others.


Exactly, I agree. All oil tests the same and honestly, except for the massive marketing departments of some of these giant oil companies.

"all oils test the same". Those are excellent words and I will be using them in these forums in the future *LOL*

Ok, then as you know, we go outside the box in these forums and we or some of us chime in on why this oil or that oil is better because of its add pack, this one is more quiet, this one more noisy, this one more moly, this one less, etc etc.
What I am saying is, to me, within that context, RATS tests are more valid then speculation about an oil being better because of an additive package.
I would prefer an actual physical test on something, whether it is relevant or not, over someones words on why something is better without a physical test. Simply because words are just that, words.

Dont mis understand me, Im not pushing an agenda, I have always said, pick any oil within the recommended type and grade at any price and any brand and you are good to go. Its up to the engine manufacturer to properly build and design an engine.

We do, as I do have preferences. I agree again with some other post in here, choose an oil in the grade recommended and you will find some that the engine is more quiet, etc, etc. That makes more sense, then choosing an oil with a certain additive package based only on marketing.
Personally I like quiet and believe it or not, 90% or more of the time I use plain old conventional oils. I never had an engine failure in my life, never had an engine burn oil in my life. I simply change at the recommended OCI or before, normally before.

Again to the OP. This was one of the most refreshing threads in here, one that actually makes us think and discuss.
 
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Rat can't even describe what the "film" is...

In actual lubrication, there's such a thing as "minimum oil film thickness", which is hydrodynamic/EHD, is calculable in the rigid definition, or in the elastic regime.

RAT discounts all regular tribology for engine oils, and then calculates is "film strength" based on an assumed applied pressure over the estimated wear scar area...i.e. the oil has failed at "keeping them separated", which makes it at best an additive test, which is why these tests are typically used for gears and roller bearings.

Then he goes on about the meaningless of NOACK, as his smoke test is better.

HTHS viscosity doesn't show in his additive test, so it's immediately discounted as real too.

There are truckloads of "physical tests" in the API suite...and they are all very very expensive.

So if RAT were ale to demonstrate that HIS physical test was at least as good as the (expensive) Sequence IVA warmup wear test, then he'd be rich, and the test would be his test rig, not an (expensive) old Nissan engine.

He claims it's not the one armed bandit, then goes all one armed bandit fair ground on his conclusions.
 
I am not buying the RAT blog either. He claims to be a mechanical engineer,et al, and says he is writing as a layman so the audience can understand it. The entire flow of his thinking is not scientific. He also personally attacks his critics constantly, saying only he knows the truth. No true engineer, coming from scientific point of view, would ever do that. The data and test methods either prove or fail to prove.
I wonder how many times he uses "I" in that blog?
 
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Originally Posted By: alarmguy
Ok, then as you know, we go outside the box in these forums and we or some of us chime in on why this oil or that oil is better because of its add pack, this one is more quiet, this one more noisy, this one more moly, this one less, etc etc.
What I am saying is, to me, within that context, RATS tests are more valid then speculation about an oil being better because of an additive package.

I would prefer an actual physical test on something, whether it is relevant or not, over someones words on why something is better without a physical test. Simply because words are just that, words.

But that's just it, none of his results are able to indicate a statistically valid difference between any of the oils he tested. The ranking he provides is complete fantasy. What he should have reported is that the test is unable to distinguish any differences between any of the oils he tested and as a result they cannot be ranked.

There are valid tests to show whether an oil is suitable for a particular use. But his test and (his results) is not one of them. People keep wanting and trying to ascribe some relevancy to this website and that ranking but there is absolutely none to be obtained.
 
Unless the physical testing is done in a repeatable, scientific, peer reviewed manner, it probably doesn't mean anything.
Let's say I want to comparison test the face hardness of two hammer models. I put my finger on an anvil, and strike said finger with both hammers. That is a physical test. Does it prove anything?
Now, what I should do is go out and private purchase, say 25 of each hammer, from various vendors across the U.S. Then, I could test the Rockwell on each head, average the results, send the test data to another hammer tester
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This tester goes out, buys the same models, tests the same way, same laboratory conditions, complies his data, and sends both sets to the a third tester, same thing. The third tester sends all sets back to you. You compile all data, write your paper, and send it to 5 more qualified hammer testers for peer review. They all say it is good. Then you publish your data in a scientific journal. Your conclusion would read something like" based on a random sample, the data do support the average Rockwell hardness of X hammer face is ___. The Data do support the average Rockwell hardness of Y hammer face is ____."
This is way over simplified, but that is the gist.
 
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None of that is necessary in this case however. You don't need to publish your results and have them reviewed by your peers for validity, that is the point of an ASTM standard test.

But it's worse than his presentation of the data. The test is not intended for nor is it applicable to motor oils. Second, he admits to not using the actual ASTM test equipment, so right there that invalidates any results. But the real nail in the coffin is that he does not analyze and present the results in accordance with the requirements of the ASTM procedure. If he did, then the error bars on the results show that there is no difference between any of the oils in regards to his results.

Originally Posted By: bigj_16
Unless the physical testing is done in a repeatable, scientific, peer reviewed manner, it probably doesn't mean anything.
Let's say I want to comparison test the face hardness of two hammer models. I put my finger on an anvil, and strike said finger with both hammers. That is a physical test. Does it prove anything?
Now, what I should do is go out and private purchase, say 25 of each hammer, from various vendors across the U.S. Then, I could test the Rockwell on each head, average the results, send the test data to another hammer tester
smile.gif
This tester goes out, buys the same models, tests the same way, same laboratory conditions, complies his data, and sends both sets to the a third tester, same thing. The third tester sends all sets back to you. You compile all data, write your paper, and send it to 5 more qualified hammer testers for peer review. They all say it is good. Then you publish your data in a scientific journal. Your conclusion would read something like" based on a random sample, the data do support the average Rockwell hardness of X hammer face is ___. The Data do support the average Rockwell hardness of Y hammer face is ____."
This is way over simplified, but that is the gist.
 
Originally Posted By: kschachn
None of that is necessary in this case however. You don't need to publish your results and have them reviewed by your peers for validity, that is the point of an ASTM standard test.

But it's worse than his presentation of the data. The test is not intended for nor is it applicable to motor oils. Second, he admits to not using the actual ASTM test equipment, so right there that invalidates any results. But the real nail in the coffin is that he does not analyze and present the results in accordance with the requirements of the ASTM procedure. If he did, then the error bars on the results show that there is no difference between any of the oils in regards to his results.

Originally Posted By: bigj_16
Unless the physical testing is done in a repeatable, scientific, peer reviewed manner, it probably doesn't mean anything.
Let's say I want to comparison test the face hardness of two hammer models. I put my finger on an anvil, and strike said finger with both hammers. That is a physical test. Does it prove anything?
Now, what I should do is go out and private purchase, say 25 of each hammer, from various vendors across the U.S. Then, I could test the Rockwell on each head, average the results, send the test data to another hammer tester
smile.gif
This tester goes out, buys the same models, tests the same way, same laboratory conditions, complies his data, and sends both sets to the a third tester, same thing. The third tester sends all sets back to you. You compile all data, write your paper, and send it to 5 more qualified hammer testers for peer review. They all say it is good. Then you publish your data in a scientific journal. Your conclusion would read something like" based on a random sample, the data do support the average Rockwell hardness of X hammer face is ___. The Data do support the average Rockwell hardness of Y hammer face is ____."
This is way over simplified, but that is the gist.

That is kind of my point also. He is not using any ASTM procedure(or anything else), therefore he needs to validate his testing.
 
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