Another "Taxi" Study: Relationship of Engine Bearing Wear and Oil Rheology 872128

[Bill7]

Right. Shannow invented the XW/HTHS grade. Pick your winter grade and desired HTHS. All that is in between, is not important.

The XW/HTHS grade measurement is on the right track but perhaps not precise enough.
Each oil range (ex: 5W-30) has a wide viscosity range (ex: [email protected] and HTHS range) that it allows, so if you happen to get a thin 5W-30, it might be about the same as a thick 5W-20.

I like to choose thick 5W-30's that are approaching the upper limits of thickness in the 5W-30 viscosity range spectrum,
so you can get the full benefits of a higher HTHS and high MOFT.

Personally, I also like to use high mileage oil, only because I like that it treats all the oil seals in the engine to keep them at the soft original
size they were when they were new, to prevent external oil leaks on your driveway or garage floor. It also stops internal oil leaks which can reduce oil burning.

I buy all my oil in 5 quart jugs from Walmart, and all my filters from Walmart or Amazon, and then just pay $14 labor for my local tire shop to do the oil change. I try to avoid going to places that use the cheapest bulk oil and the $2 oil filters and then pad their profit by charging you $40 to $50 for the oil change. They are not a really good value for the consumer in my opinion.

 

[userfriendly]

I have a question; What would the military do in this situation when lives depend on machinery and mobilization? Go for marginally adequate and maybe save a few bucks with improved fuel effeciency? I noticed radiometer's 48th armored patch and several others retired and active here.
I'm sure they have an opinion.

 

[Bill_W]

I have a question; What would the military do in this situation when lives depend on machinery and mobilization? Go for marginally adequate and maybe save a few bucks with improved fuel effeciency? I noticed radiometer's 48th armored patch and several others retired and active here.
I'm sure they have an opinion.

Why… they would post it here?

 

[ZeeOSix]

I have a question; What would the military do in this situation when lives depend on machinery and mobilization? Go for marginally adequate and maybe save a few bucks with improved fuel effeciency? I noticed radiometer's 48th armored patch and several others retired and active here.
I'm sure they have an opinion.

The military has a lot of it's own testing and resulting "Mil Specs" to ensure everything is able to meet the tasks at hand over all possible conditions ... and with some headroom built-in, not specified to run just on the ragged edge of things. They also do a lot of their own oil and lubrication performance testing.

 

[Bill_W]

The military has a lot of it's own testing and resulting "Mil Specs" to ensure everything is able to meet the tasks at hand over all possible conditions ... and with some headroom built-in, not specified to run just on the ragged edge of things. They also do a lot of their own oil and lubrication performance testing.

Feasibility of Using Full Synthetic Low Viscosity Engine Oil at High Ambient Temperatures in Military Vehicles

The US Army is currently assessing the feasibility and defining the requirements of a Single Common Powertrain Lubricant (SCPL). This new lubricant would consist of an all-season (arctic to desert), fuel-efficient, multifunctional powertrain fluid with extended drain capabilities. As a development

www.sae.org

Military is mainly diesel engines.

 

[ZeeOSix]

Feasibility of Using Full Synthetic Low Viscosity Engine Oil at High Ambient Temperatures in Military Vehicles

The US Army is currently assessing the feasibility and defining the requirements of a Single Common Powertrain Lubricant (SCPL). This new lubricant would consist of an all-season (arctic to desert), fuel-efficient, multifunctional powertrain fluid with extended drain capabilities. As a development

www.sae.org

Military is mainly diesel engines.

Looks like the "arctic" low viscosity is a 30 weight based on it's designation OEA-30.

FlexPaper AdaptiveUI JSP Example

This is from the link. Note the part about more wear over the life of the equipment and the tone of is it "acceptable". Almost sound like the military version of CAFE, lol

And the military engineers obviously understand Tribology and the connection between viscosity, MOFT and wear... it's said right in the snip-it.

 

[Bill_W]

Looks like the "antic" low viscosity is a 30 weight based on it's designation OEA-30.

FlexPaper AdaptiveUI JSP Example

This is from the link. Note the part about more wear over the life of the equipment and the tone of is it "acceptable". Almost sound like the military version of CAFE, lol

And the military engineers obviously understand Tribology and the connection between MOFT and wear... it's said right in the snip-it.

View attachment 137323

https://apps.dtic.mil/sti/pdfs/ADA624797.pdf

 

[CR94]

... I like to choose thick 5W-30's that are approaching the upper limits of thickness in the 5W-30 viscosity range spectrum,
so you can get the full benefits of a higher HTHS and high MOFT. ...

How exactly is that better than a 5W-40 that's approaching the upper limits of thickness in the 5W-40 viscosity range spectrum, which would provide you even higher HTHS and higher MOFT?

 

[Bill7]

Looks like the "antic" low viscosity is a 30 weight based on it's designation OEA-30.

FlexPaper AdaptiveUI JSP Example

This is from the link. Note the part about more wear over the life of the equipment and the tone of is it "acceptable". Almost sound like the military version of CAFE, lol

And the military engineers obviously understand Tribology and the connection between viscosity, MOFT and wear... it's said right in the snip-it.

View attachment 137323

Even the military thinks lower viscosity oils are likely to produce more engine wear and is doing testing to see if they have the
"required minimum oil film thickness" (aka MOFT).

Precisely the same MOFT that ZeeOSix has been mentioning in most of his posts as being the essential criteria for engine protection.

When we debate thick versus thin, I think ZeeOSix is correct and we should put much more importance on what he is saying.

 

[ZeeOSix]

https://apps.dtic.mil/sti/pdfs/ADA624797.pdf

From the paper:

4.0 CONCLUSIONS

"Lastly, the ASTM D5966 Roller Follower Wear Test demonstrated that each
revised candidate provided adequate protection to critical roller follower valve train components."

"Lastly, fuel consumption improvements were found to be similar for both revised candidate
lubricants. Results help confirm that through the use of low viscosity lubricants, potential fuel
savings for the military could be realized. The 2.55% improvement over the SAE40 baseline oil
translates into an approximate 1.5% improvement over MIL-PRF-2104H 15W-40 diesel engine
oils [4]. These savings, combined with goals of extended drain intervals, all help in making an
SCPL lubricant potentially cost effective when compared to current products.".

-----------------------------

"Adequate protection" ... the military is forming it's own "CAFE" it seems, lol.

Saving a potential 1.5% max in fuel doesn't do much good when the equipment might wear out faster and need more frequent rebuilding or replacement ... or more importantly, it suffers mechanical issues on the battle field and it and its operators may get taken out as a result. And if the oil costs much more, even though it might be able to be ran longer, it still may come out as an added cost that would offset savings in fuel. Lot's of factors going on when the whole picture is looked at.

Was the military successful with this program and are they actually now using a SCPL lubricant per the research goal? Or was this just a very expensive research program that concluded that what they know and were doing with oils already works well, and should just be left alone.

 

[Bill7]

How exactly is that better than a 5W-40 that's approaching the upper limits of thickness in the 5W-40 viscosity range spectrum, which would provide you even higher HTHS and higher MOFT?

From what I have read, after you reach HTHS = 3.5, there is only a very small additional wear protection benefit from increasing HTHS.
5W-40 oils are fine. By the SAE guidelines, any oil labeled as xW-40 needs to have a minimum HTHS of 3.5.

One consideration about running xW-40 oils is API SP limits the phosphorus content for all weights below 40, but not for 40 or higher weights.
So if you use an API SP xW-30, it will have a safe phosphorus level so you won't harm your catalytic converter.
But if you use an API SP xW-40, it could have a higher phosphorus content and could damage your catalytic converter.

 

[Bill7]

From the paper:

4.0 CONCLUSIONS

"Lastly, the ASTM D5966 Roller Follower Wear Test demonstrated that each
revised candidate provided adequate protection to critical roller follower valve train components."

"Lastly, fuel consumption improvements were found to be similar for both revised candidate
lubricants. Results help confirm that through the use of low viscosity lubricants, potential fuel
savings for the military could be realized. The 2.55% improvement over the SAE40 baseline oil
translates into an approximate 1.5% improvement over MIL-PRF-2104H 15W-40 diesel engine
oils [4]. These savings, combined with goals of extended drain intervals, all help in making an
SCPL lubricant potentially cost effective when compared to current products.".

-----------------------------

"Adequate protection" ... the military is forming it's own "CAFE" it seems, lol.

Saving a potential 1.5% max in fuel doesn't do much good when the equipment might wear out faster and need more frequent rebuilding or replacement ... or more importantly, it suffers mechanical issues on the battle field and it and its operators may get taken out as a result. And if the oil costs much more, even though it might be able to be ran longer, it still may come out as an added cost that would offset savings in fuel. Lot's of factors going on when the whole picture is looked at.

Was the military successful with this program and are they actually now using a SCPL lubricant per the research goal? Or was this just a very expensive research program that concluded that what they know and were doing with oils already works well, and should just be

Interesting they used the words: "adequate protection".

I believe Honda used the same words when they were switching their vehicles to 20 weight oils in the early 2000's.

No one ever uses the words "optimal protection" when describing a switch to thinner oils, because thinner oils never provide "optimal protection". Heavy duty diesel engines are suppossed to run xW-40 oils, and not be back speced to a lower HTHS lower MOFT oil that will cause more engine wear.

 

[OVERKILL]

Interesting they used the words: "adequate protection".

I believe Honda used the same words when they were switching their vehicles to 20 weight oils in the early 2000's.

No one ever uses the words "optimal protection" when describing a switch to thinner oils, because thinner oils never provide "optimal protection". Heavy duty diesel engines are suppossed to run xW-40 oils, and not be back speced to a lower HTHS lower MOFT oil that will cause more engine wear.

Not sure about the switch to xW-20, but in the discussion about going below that, Honda certainly spoke on achieving "adequate" wear control, achieved through the use of wider bearings and special coatings.

 

[CR94]

From what I have read, after you reach HTHS = 3.5, there is only a very small additional wear protection benefit from increasing HTHS. ...

That number might depend on the way the engine is designed and used, instead of being rigidly fixed for all circumstances.

 

[ZeeOSix]

Heavy duty diesel engines are suppossed to run xW-40 oils, and not be back speced to a lower HTHS lower MOFT oil that will cause more engine wear.

There have been some related articles also posted here over the years where they discuss using thinner oils in the commercial trucking industry. Of course, it again becomes a balancing act of "acceptable wear" vs the "advantages" (fuel mileage) as the oil viscosity becomes thinner and thinner.

If you read that PDF linked about the military program, they want to find one oil that will work in every part of the power trains (engine, transmission, differentials) - hence the name "Single Common Powertrain Lubricant (SCPL). IMO, they are dreaming without going deep into the "adequate protection" realm and getting into "borderline protection". When's the last time anyone has seen the same lube put in the differentials that was also used in the engine?

 

[Bill7]

There have been some related articles also posted here over the years where they discuss using thinner oils in the commercial trucking industry. Of course, it again becomes a balancing act of "acceptable wear" vs the "advantages" (fuel mileage) as the oil viscosity becomes thinner and thinner.

If you read that PDF linked about the military program, they want to find one oil that will work in every part of the power trains (engine, transmission, differentials) - hence the name "Single Common Powertrain Lubricant (SCPL). IMO, they are dreaming without going deep into the "adequate protection" realm and getting into "borderline protection". When's the last time anyone has seen the same lube put in the differentials that was also used in the engine?

Good post ZeeOSix"
You mentioned: "IMO, they are dreaming without going deep into the "adequate protection" realm and getting into "borderline protection"."

For regular passenger cars, the newer viscosities are now also making the transition from "adequate protection" to "borderline protection".

In my opinion, oil viscosity was just right back in the 1980's where they advised using 30 weight oil in the winter and 40 weight oil in the summer for most cars. I can understand 20 weight oils with HTHS = 2.6 being ok. But the march to HTHS 2.3 (0W-16) and thinner oils might be a transition to "borderline protection".

Another fluid that has gotten a lot thinner is Automatic transmission fluid. I've noticed the genuine Toyota World Standard (WS) Automatic Transmission fluid has gotten ultra thin. Kinetic Viscosity: 5.5 cSt @100C. At least the Amsoil Signature Series ATF is still 7.5 cST @100C.

Automakers can't wait to thin out their fluid's more and more. Even the German automakers are joining the thin crowd and specing thinner and thinner fluids. At some point, 0W-5 fluids will be commonplace (2023 Toyota Crown is already specing 0W-8).

It's gotten to a point where I just want to use my HTHS = 3.2 with high MOFT oil and my Amsoil SS ATF at KV [email protected] transmission fluid in any car I own for the rest of my life, and not be affected by the move to ultra thin fluids and their "borderline protection".

 

[userfriendly]

https://apps.dtic.mil/sti/pdfs/ADA624797.pdf

The pdf is unclassified, so we know where it didn't come from.
Page 35, 1st para; What does "candidates (test lubricants) do cautiously appear to provide adequate protection" mean?
Word salad 101?

 

[DuckRyder]

Page 35, 1st para; What does "candidates (test lubricants) do cautiously appear to provide adequate protection" mean?

My translation would be "We think it wont blow up" or "nothing has spit a rod out yet". Or perhaps "I'll be retired before its an issue".

 

[TiGeo]

Timely post from the book o' faces...

 

[demarpaint]

Interesting they used the words: "adequate protection".

I believe Honda used the same words when they were switching their vehicles to 20 weight oils in the early 2000's.

No one ever uses the words "optimal protection" when describing a switch to thinner oils, because thinner oils never provide "optimal protection". Heavy duty diesel engines are suppossed to run xW-40 oils, and not be back speced to a lower HTHS lower MOFT oil that will cause more engine wear.

I've been saying that for quite a few years now. With all the words in the English language why pick the word "adequate" if these "thin oils" are so great? My guess: they picked the right word, "adequate," because if it were "superior" they would have used that word.