A little free education

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With a furious debate on a single bench test (legitimate or not) sparking all kinds of posts about ranking oils I thought I'd provide a little insight into industry specifications.

Read Here about the most recent ASTM committee meeting on Lubricant Test Methods - Steve does an excellent job here discussing the major changes that are currently underway replacing old sequence engine tests that are used for ASTM, ACEA and other credentials, as well as talks about the challenges of the new tests that are being developed an how they apply to your new engines.

You may not know this, but the OEM's wanted GF-6 rolled out already, this is because the technology making up the 2017 model year cars needs engine oil to address new issues. It's kind of a big deal if you have a new car and are using GF-5 based oils with some manufacturers. Unfortunately the testing and certification process for new technologies is taking longer than it should. This is why you are seeing OEM's push even more for their own specifications vs the one-size-fits-all approach of the API.

This information from Lubrizol is a good look at the new Dexos1 specification and what these tests are actually evaluating. You can see from the description (and if you compare it to the GF-5 current standard) that this program is focusing on alot more than making GM money in registrations and royalty fees - although that is happening too.

You can download the 2016 ACEA Oil Sequences here and again - looking at the testing requirements and the list of OEM's involved (BMW Group,DAF Trucks NV,Daimler AG,Fiat SpA,Ford of Europe GmbH,General Motors Europe AG,Hyundai Motor Europe GmbH,IVECO SpA,Jaguar Land Rover,PSA Peugeot Citroen,Renault SA,Toyota Motor Europe SA,Volkswagen AG,AB Volvo,Volvo Car Corporation) you can see that OEMs are again highly engaged in trying to make sure that the engines they design can be maintained with quality oils. This requires a lot of testing which is expensive, but can clearly demonstrate that an oil operates in the conditions that the engines were designed for. Also if you want to see Videos about how these tests are run, they are available.

On top of this there are also the extensive list of OEM credentials - which aren't designed to make one oil (say the one that meets them all) better than another. There is no all encompassing list of oils or method to rank and get the "Holy Grail" of engine oil technology. We aren't able to definitively say which oil is best because the market is always changing and no two vehicles are exactly alike. In fact if you read the Motor Oil University on the main page, we included a section all about that: Motor Oil 106

If you have questions about any of the above specifications, or others, I am happy to help out. I'm not always on the board, but when I am I will try to respond in this thread. There are also several others that are very knowledgeable about these specifications and would be able to chime in.
 
The video link above wasn't working so here they are:






Both videos talk about what it takes to run a REAL engine test.
 
Thank you very much! Really appreciate this contribution
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Solarent - thanks for the info.

Looking at the wear tests in the 2016 ACEA Oil Sequences you lined to above, on page 8 of 16 for Gasoline and Light Duty Diesel Engines (A3/B3, A3/B4 & A5/B5 categories) using test method CEC L–099-08, it shows they only test for and have wear limits for cam, tappet and cylinder wear. Noting found at all for bearing or any other engine components wear.

I couldn't find any details ('net searching) on how they run the engine tests and for how long with each test oil, or how they measure the wear (down to microns), so I was wondering if you have any inside info on that?

Also I found it interesting that the wear limits to pass the wear test is 20-24 times less for the cylinders than for the cams and tappets. Maybe because they know cams and tappets are harder to prevent wear in than cylinders? I have a feeling that if those wear limits were much lower that a lot of oils tested might not pass - your thoughts?
 
Here is the Summary of the L-099-08 test protocol:
Originally Posted By: CECL-99-08(S)

Hardware: A Mercedes-Benz four cylinder in-line light duty diesel engine is used for this test. The internal Mercedes Benz coding for this engine is OM646 DE 22 LA and it is installed in various passenger cars and light duty trucks. The engine is a 2.2 litre common rail diesel engine rated at 110 kW with approximately 6.5 litres volume of engine oil. It is fitted with a chain driven Lanchester vibration balancer and chain driven camshafts equipped with variable Cam Phaser.

Test: The breaking-in of the engine includes an engine performance check and an oil consumption run with a reference oil. The main part of the test is a 300 h alternating phase on the respective candidate oil.
A high portion of the test is running under full load conditions or in a fuel consumption controlled mode close to full load operation.
Controlled oil top ups are allowed during the test up to 250 h of the running time. Frequent oil samples are taken in order to monitor the oil performance throughout the test. Visual ratings as well as pre- and post test measurements of all relevant engine parts are carried out for the evaluation of the engine
condition at end of test
.

CEC Target parameter: Cam wear; outlet cam wear is the only parameter to have received formal
approval from CEC, inlet cam wear is statistically monitored and might become an approved parameter in future.

Auxiliary parameter: Cylinder wear, Bore polishing, Piston cleanliness, Engine sludge, Ring sticking,Tappet wear, Bearing wear, Piston ring wear, Timing chain wear
CEC Testing


For your question about cylinder wear vs Cam/Tappet wear, that's really a question for MB because it's their engine, however in general the limits on cam wear are typically higher than tests for cylinder wear. This is a trend across most specifications.

There are a couple of things to keep in mind regarding these tests - often the protocols are designed to look at specific section of the engine (not the engine as a whole) - for example the new GF-6 test on chain wear ignores a lot of other engine parts because the dirty up cycles and soot issues need to be simulated in a testing environment, so the parameters like how long an oil is run, at what engine speed and load is all designed to look at the specific issue of chain wear. Other tests look at the other areas - like weighted bearing loss, ring weight loss etc.

Also when it comes to most specifications controlling deposits, sludge and varnish (especially in the piston skirt, around the rings and on the piston) is as important or arguably more important than scuffing wear - this is talking about gasoline engines only. More of the tests that are used to evaluate an oil are focused on that because the issues you will have with an engine full of deposits is more common and arguably worse than one suffering from normal wear - most engine oils do a fine job of protecting against wear under normal conditions.
I should be careful with that last comment because people are probably going to quote me on that, I'm talking more about what is looked at from a specification point of view - wear is still really important, but deposits, sludge and varnish are equally important and all these things are not happening in a vacuum. An oil that excels in the CEC L-099-08 may perform terribly in an equally important, valid engine test which is part of the specification. Even OEM specifications are typically based on multiple engine tests. No single test can be used to declare one oil good and the rest rubbish.
 
Originally Posted By: ZeeOSix
Also I found it interesting that the wear limits to pass the wear test is 20-24 times less for the cylinders than for the cams and tappets.


Different geometry, different operating conditions, different points on the stribeck curve, different kinematics, and different operational effects as wear progresses.

If bearings are in hydrodynamic (HTHS limits see to that), then they don't need EP.
 
Solarent - thanks for the added details on the CEC L–099-08 test methods.

Originally Posted By: Solarent
For your question about cylinder wear vs Cam/Tappet wear, that's really a question for MB because it's their engine, however in general the limits on cam wear are typically higher than tests for cylinder wear. This is a trend across most specifications.


I didn't get the impression the ACEA Oil Sequence tests were for a specific engine, but rather a baseline spec to certify & register the oil to a test standard for EU like oils here are certified (by API or ???).

It does say: "The Oil Sequences define the minimum quality level of a product for self certification to EELQMS and presentation to ACEA members. Individual member companies may indicate performance parameters other than those covered by the tests shown or more stringent limits."

So sounds like automakers could tighten up the test pass/fail limits if they deemed necessary. How would those oils be marked to distinguish that they passed more stringent tests than the baseline ACEA sequence?

Originally Posted By: Shannow
Originally Posted By: ZeeOSix
Also I found it interesting that the wear limits to pass the wear test is 20-24 times less for the cylinders than for the cams and tappets.


Different geometry, different operating conditions, different points on the stribeck curve, different kinematics, and different operational effects as wear progresses.

If bearings are in hydrodynamic (HTHS limits see to that), then they don't need EP.


Agreed, and because of their different geometry and kinematics it seems that cams/lifers/tappets would require better lubrication EP/AW performance than other engine components. If not, I'd think the set wear limits in an engine test like this would have lower pass/fall limits. If those limits were cut in half, would the same oils pass? Who decides on those ACEA test sequence baseline wear limits, and based on what criteria?

It would be interesting to see the actual wear measurement results of a variety of different oils tested to see how they stacked up against each other. Bet that info is most likely "proprietary".

And yes, journal bearings in hydrodynamic lubrication should ideally never wear, but was wondering if maybe they test for bearing wear by running a high number of simulated cold start cycles or maybe extreme oil temperatures to check for break down that would lead to bearing MOFT failure.
 
Originally Posted By: ZeeOSix
I didn't get the impression the ACEA Oil Sequence tests were for a specific engine, but rather a baseline spec to certify & register the oil to a test standard for EU like oils here are certified (by API or ???).

It does say: "The Oil Sequences define the minimum quality level of a product for self certification to EELQMS and presentation to ACEA members. Individual member companies may indicate performance parameters other than those covered by the tests shown or more stringent limits."


It's the same as the API et al.

Multiple OEMs submit a particular engine based test that is then tested for repeatability by the various members, who then decide to accept it as a standard...when the engine is well out of date, they then try to find a modern(er) engine based test that gives comparable results to the now obsolete gear.

If you look at (google) the recently released diesel API specs, you can find loads of minutes of meetings of working groups evaluating test protocols for repeatability (and indeed ranking), before deciding that they are a part of the accepted test suite.

Some OEMs don't get their issue of choice into the standard, so have their own test.

As to Performance against standard, a fairly "well connected" poster has indicated that for the Sequence IVA (cam wear during simulated warm-up...i.e. NOT at Rat temperatures), the company acceptance criteria is 40% of the allowable limit...and yes, in that specific test, some of the oil companies have advertised comparative performance.
 
A really good example of what Shannow is talking about is the LSPI tests for Dexos1 and GF-6. Both Ford and GM have developed LSPI test methods, but including both in the standard was a non-starter. So GM put their test into the Dexos1 certification and the Ford test is being finalized for GF-6.

Interestingly if a product claims both Dexos1 and GF-6 it will have to pass both tests.
 
Originally Posted By: ZeeOSix
was wondering if maybe they test for bearing wear by running a high number of simulated cold start cycles or maybe extreme oil temperatures to check for break down that would lead to bearing MOFT failure.


This is why there is so much confusion about the way oils are tested - for those not in the industry, it probably makes sense to simulate cold start cycles or to push the oil to extreme temperatures. And while some of this "torture testing" is done for certain types of lubricants, in engine testing it's more complex than that. I could simulate cold starts using the CCS or MRV in an attempt to correlate those results with start-up wear, but in reality that has very little to do with real-world problems in the industry.

Whenever a new API category is proposed, the automakers issues a "Needs Statement" which outlines what their concerns are based on i) issues they are currently having with warranties etc and ii) developing technology and how the current engine tests relate (or don't relate) to these new technologies. It's this Needs Statement that forms the basis of developing new engine tests.
 
Originally Posted By: Solarent

There are a couple of things to keep in mind regarding these tests - often the protocols are designed to look at specific section of the engine (not the engine as a whole) - for example the new GF-6 test on chain wear ignores a lot of other engine parts because the dirty up cycles and soot issues need to be simulated in a testing environment, so the parameters like how long an oil is run, at what engine speed and load is all designed to look at the specific issue of chain wear. Other tests look at the other areas - like weighted bearing loss, ring weight loss etc.

Also when it comes to most specifications controlling deposits, sludge and varnish (especially in the piston skirt, around the rings and on the piston) is as important or arguably more important than scuffing wear - this is talking about gasoline engines only. More of the tests that are used to evaluate an oil are focused on that because the issues you will have with an engine full of deposits is more common and arguably worse than one suffering from normal wear - most engine oils do a fine job of protecting against wear under normal conditions.

I should be careful with that last comment because people are probably going to quote me on that, I'm talking more about what is looked at from a specification point of view - wear is still really important, but deposits, sludge and varnish are equally important and all these things are not happening in a vacuum. An oil that excels in the CEC L-099-08 may perform terribly in an equally important, valid engine test which is part of the specification. Even OEM specifications are typically based on multiple engine tests. No single test can be used to declare one oil good and the rest rubbish.



An excellent set of Engine Test Explanations. Thanks for including that last sentence.

In formulating engine oils for specific applications a manf. may emphasize deposit control in his requirement statement. You then formulate for enhanced deposit control (but with wear, rust inhibition, etc included as well), ship them a 5 gal. pail or tote for testing, and then after the tests he says that after teardown the engine is very clean but they noticed higher than normal bearing wear. You then find out this engine is used to power grinders in a waste water plant where hydrogen sulfide gases are in concentration.

So it is back to the drawing (formulation) board to re-formulate and attempt to provide an oil that covers all bases. Using baseball as an example, this final formulation "slides" onto to some bases while it makes definite contact with the other bases.
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