Can thicker oil cause more wear?

I trust the manufacturer recommendations much more these days. With product mixes that have EVs, mainstream turbocharging success, and flattened CAFE requirements there is less pressure to meet fleet averages. Engine and oil technologies are more mature. If the engine needs a 0w-40, like some Dodge and GM V-8s, then that is on the oil cap. Ford has spec'd 0w-50 for some Mustang engines, another example.

The one caveat I have with this thinking is how different OEM oil viscosity recommendations can be based on the country its sold in and its emissions/fuel economy regulations. In my particular car its specifies 0w/5w-20. The same car a year earliers manual specifies 5w-30, but they added piston oil squirters starting my year so that was understandable to me. But the russian manual for cars with my engine for all years says use anything from 0w-20 to 10w-40 depending on the temperature. Its possible the engines were made at different factories etc but its such a big jump.
 
The one caveat I have with this thinking is how different OEM oil viscosity recommendations can be based on the country its sold in and its emissions/fuel economy regulations. In my particular car its specifies 0w/5w-20. The same car a year earliers manual specifies 5w-30, but they added piston oil squirters starting my year so that was understandable to me. But the russian manual for cars with my engine for all years says use anything from 0w-20 to 10w-40 depending on the temperature. Its possible the engines were made at different factories etc but its such a big jump.
Not really, if all this has shown us one thing is that engines are mechanically tolerant of a variety of grades. As long as the MOFT is adequate then excessive wear will not occur.

The number one reason US owner's manuals strongly demand a certain grade is because that's the one that was used during CAFE credit certification. The award letters that have been posted here (and are available elsewhere) document how the manual is to be worded. But none of it is technically mandated. No engine is going to be damaged by a somewhat higher HT/HS and invalidate a warranty due to oil-induced failure. Engines can be designed and built to tolerate low HT/HS oils but that doesn't preclude their operation on one that is higher.

The only advantage to a lower grade oil is fuel economy. Nothing else.
 
Not really, if all this has shown us one thing is that engines are mechanically tolerant of a variety of grades. As long as the MOFT is adequate then excessive wear will not occur.

The number one reason US owner's manuals strongly demand a certain grade is because that's the one that was used during CAFE credit certification. The award letters that have been posted here (and are available elsewhere) document how the manual is to be worded. But none of it is technically mandated. No engine is going to be damaged by a somewhat higher HT/HS and invalidate a warranty due to oil-induced failure. Engines can be designed and built to tolerate low HT/HS oils but that doesn't preclude their operation on one that is higher.

The only advantage to a lower grade oil is fuel economy. Nothing else.
Thats exactly what im saying, I dont really agree with limiting yourself to the owners manual or oil cap recommendation, as the person i was replying to implied is the best course of action.
 
The only advantage to a lower grade oil is fuel economy. Nothing else.
Slightly less torque squandered on viscous drag results not only in slightly lower fuel consumption at a given speed and output torque, but also in slightly more output torque available.
 
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Slightly less torque squandered on viscous drag results not only in slightly lower fuel consumption at a given speed and output torque, but also in slightly more output torque available.
True, but that added hair of torque/power couldn't be felt unless the engine was pretty anemic to start with.
 
If fuel economy improvement is in the 1 to 1.5 percent region when going
from say a 5W-30 to a 0W-20 I'd assume power gains shouldn't be far off.
Hardly noticeable, but it's there. I have to admit after going from 5W-40 to
0W-30 I surmised the car felt a tad more lively. If it matters I finally settled
on running 5W-30. Is that car anemic? It's probably a matter of your point
of view. 370 Nm = 272 lb-ft at 1380 kg = 3040 lbs.
 
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OK, now for the only “Thin Advocate”...

Ferrari manuals often recommend an ideal viscosity for operation. It is defined as 70 PSI at 6,000 RPM. It can be more or less but this is the ideal range. It is not defined as “at least” or “a minimum of”. Some manuals say a 5W40 should be good under all conditions while other manuals suggest the Shell Helix Ultra 10W60 for track use in high temperature environments. Note that the 60 grade oil is barely above a 50 grade off the shelf and rapidly thins with use.

Millions of cars and trucks, in all environments and conditions, have been using 20 grade oils for decades now with no adverse effects. Personally I cannot understand why people would insist on using a thicker oil than needed resulting in less power and reduced fuel economy.

Everybody seems to think bearing wear is the limiting factor for engine longevity. I believe it is piston ring wear in a properly maintained engine. I had a discussion with one of the leaders in lubrication research about this very issue:

Ali,

Thanks for the note. I've seen these slides before, but unfortunately I've never seen it presented live to be able to ask questions. I guess that the argument is that this is a starved lubricant condition, and the low vis oils have a higher flow and a better chance at getting to the ring/bore surface, even though they would provide lower film thickness in a fully flooded condition.

Film thickness is probably not the issue at top ring reversal, where we're always in boundary lubrication anyway. But, oil starvation would be an issue. Anything that promotes getting lubricant to the contact will be beneficial for maintaining the antiwear films. Unfortunately, too much lubricant at the top ring causes increased oil consumption. So, there's always a balance between too much and too little oil. This can be influenced by oil ring tension and cylinder bore finish as well as oil viscosity.

Regards,

Eric

Eric W. Schneider

I do believe that the engine manufacturers design power plants and matching oils to be useful in any encounterable circumstances. However, you can go up or down a grade if you need to fine tune for your specific application. As I do not track cars any more I always use a grade (or two) lower as pressure/RPM values allow for it.

Regarding cold starts. First of all this is defined as anything less than a fully warmed up engine. Here in Florida it is usually around 70 - 80F in the AM. Eric Schneider has shown that test engines under load will warm the oil up to the normal operating temperature during a 15-20 minute period. Engine wear decreases linearly as the oil warms (and thins). And this is in an engine starting at 75F. To further show that viscosity matters he artificially cooled only the oil back down to 75F and the wear linearly increased back to the highest level again.

To me, this indicates that we should always use the least thickening oil during the start up period. I go for the proper, indicated grade (usually a 20 or 30). Then use the least thick oil viscosity at start up, preferably a 0W and sometimes a 5W-...

As it turns out millions of cars running today and oil testing has shown that it does not matter what you use. Your engine will likely outlast the rest of the car or truck. So why not just use an oil that gives you more power and MPG. I have never heard a person complain about having too much power and that they would prefer to slow down their engines response.

Finally I have some data (though some will say it is not enough to be worth a look) to suggest that thinner oils in high power engines result is less wear. From an older post:


“If Ferrari specifies 5W-40 oil, why are you so interested in trying something like 0W-20? Do you believe the thinner viscosity will improve performance?”

Ferrari recommends oil based on the car being on a race track. A 20 grade oil running around town is thicker than a 40 grade oil running at wide open throttle on the track using all 800 HP. As oil takes around 20 minutes to warm up to the operating temperature while driving around town it is almost always thick as honey. Most trips are for me less than 30 minutes long. Hence the oil is even thicker yet.

I have demonstrated that these Ferrari engines have less wear running lower grade oils around town than the specified oils. Yes the results are of a small sample but they all show the same tendency. Oils less honey like will allow for more power, more fuel economy, less start up wear, running at higher RPM sooner, et cetera. My current 812 Superfast has sump temperatures of 165 - 175 F as I drive around town. What am I using at most - 100 HP? 200 HP? Certainly a 20 grade oil around town is way more viscous than a 40 grade oil while racing at the Sebring track using all 800 HP for 30 minutes.

Here is some data from older posts:

It may be worth revisiting this old UOA (used oil analysis) comparison. I am giving evidence that thinner oils can be used when otherwise very heavy grades may be specified. And that thinner oils may result in much less wear than when the “recommended” oil, in the “manual” is used.

Several things to note. We are neighbors, drove the same car (but for the milage), drove the same way in the same environment. His car had what can be considered normal wear. Yet mine had a significantly reduced wear pattern. Also, the original RLI that dropped to a 20 grade oil had more wear than the newer “Enzo” formulation. But it was still less than the 60 grade Shell oil. Maybe the sweat spot for this car was a 30 grade oil for driving in our environment.

Compared Enzo Ferrari UOA from years ago: This is my neighbor’s 2003 Ferrari Enzo with a total of 8,800 miles on the left column and my 2003 Enzo with a total of 4,400 miles on the right column (middle 2 columns, earlier UOA of my car). Both cars had about 1,400 miles on the oil. His obviously had more break-in time. He had the oil changed by the Ferrari dealer using the required 10W60 Shell Helix Ultra Racing oil. I ran 0W30 Castrol GC in the second column, the original formula of RLI in the 3rd column and the “new and improved “ RLI “Dr. Haas” Enzo formula in the last column.

Tested my Enzo oils by Terry Dyson. His testing counts larger particles as well as all the smaller ones so other labs may give false lower values. At no time has the oil temperature in this engine gotten above 180 F. This latest oil has been in for nearly two years but Terry Dyson said I should just keep going (and going and going). What is particularly interesting is that the original RLI formulation dropped to a 20 grade, the newer formulation did not.

Part of the original post: I believe this formulation has been perfected and am considering it’s use in all my cars. I am not sure my wife will allow such a thick oil in her Murcielago however.

OILS: ….....Shell.... GC….RLI….RLI - “Dr. Haas Enzo Formula”
Iron___________ 32...11...7...3 (Fe in RLI VOA =2)
Chromium ____ Nickel _________2...1....0...0
Aluminum _____11...3....2...0
lead _________ 16...0....3...1
Copper _______25...8....4...3
Tin __________ Silver ________ Titanium _____ Silicon ________ 7...3....4...2
Boron ________ 1...3...16..17
Sodium _______ 8...3....10...8
Potassium ____ Molybdenum _ Phosphorus ___1026...935…1032…698
Zinc _________ 1135...1228…1055...988
Calcium ______ 1454…167...2108…1898
Barium ______ Magnesium __1219...526…53...19
Antimony ____ Vanadium ____ Fuel %Vol ____ Flash_______not done..335..320..300
Abs Oxid _____ 34...10..127...95
Abs Nitr ______ 11....8....8....7
Wtr %vol ____ Vis CS 100C __ 15.8....11.8….8.6….9.8
Vic CS 40C___not done…66….44….48
SAE Grade _____40....30....20....30
Gly test ______NEG…..0.37 “not antifreeze”…...0…..0
TBN _________not done...7.9....5.9...6.4
TAN _________not done...1.7....1.4...1.3
Visc Inde x___ not done…154...177...192
Soot_________not done...0....0.01....0

Note that the Enzo engine that specifies a 60 grade oil had very little wear while running a 20 grade oil. But again, no use of all 650 HP. It’s just not possible driving in normal conditions. While running at 8,000 RPM and using all 650 HP may require a 60 grade oil, driving around town does not. I believe based on my own experiments that these cars are better off with oil grades more appropriate for urban driving as that is all I do these days. Though tempting and offered I have not raced for quite some time. Actually the last time I was on the track it was testing the soon to be released Maybach 57 and 62. Several professional racing drivers and I gave feedback to engineers from Stuttgart. ‘Quite a thrill. Several of my suggestions were done to the car. I eventually bought the original version then later the AMG version. Again, with some added Dr. Haas modifications.

Even Lamborghini tried to get my wife and her car on the track to no avail. It was enough for her to sip some wine with Valentino Balboni in our own garage.

Ali
 
Looking at couple of these graphs, and can't help but ask the question - How much difference is really there at full operating temperature? Having said that - I'm sticking with Porsche A40 approved oils in all vehicles I own and/or maintain.

54EEC08E-AF38-4D90-A7F8-A702E2D1F6FB.jpg
Viscosity2.jpg
yODqh.jpg
 
I once ran 15W50 in my old 97 Honda Civic. It speced 5W30. I remember it felt sluggish, lol.
I once had oil changed at one of those "Quickie" places before a 1800 mile vacation trip. I never even noticed anything until we got back cause I usually did an oil change right after trips like that. When I looked at the paper work from the previous oil change, they put 20w50 in my 2002 Honda Accord instead of the 5w20! The car lasted in our family after for 18 years and over 180,000mi with zero repairs except for one new radiator.
I would never suggest anything like that, but it backs up what many say. As long as its pumping you are ok. I always stick to what manufacturer specifies myself.
 
As it turns out millions of cars running today and oil testing has shown that it does not matter what you use. Your engine will likely outlast the rest of the car or truck. So why not just use an oil that gives you more power and MPG. I have never heard a person complain about having too much power and that they would prefer to slow down their engines response.
There has been controlled engine wear testing using irradiated engine components, and they all basically show that a higher HTHS viscosity decreases wear between moving parts. Ever since tribology existed, it's been known that oil viscosity is the backbone that keeps moving parts separated, which prevents wear.

Just because a car may fall apart around the engine isn't a good enough reason for some people to go as thin as possible. IMO, a xW-30 is still the "sweet spot viscosity" that will satisfy most vehicles on the road.
 
IMO, a xW-30 is still the "sweet spot viscosity" that will satisfy most vehicles on the road.
I tend to agree with you. Since the 90s with the improved quality, innovation and advancements in modern autos, the makers and other industry experts began to label the "forever used" 10w40 almost a downright danger! DO NOT USE..... the majority of recommended oil was then a variant of, as u mention w?/30 oils. That seems to have changed with even more advanced autos. But I truly believe it is driven by one major thing... CAFE standards and the EPA which are really not evil things. Anyone can go out today and buy some of the most advanced quality oil ever produced at Walmart, Amazon, auto supply stores, internet, etc...
 
Why is that?

Something no one ever seems to acknowledge here is that the majority of wear is at start-up and has nothing to do with whatever the oil is and more to due with the combustion process dumping acidic compounds and even water into the sump to the point that cars short tripped and idled excessively when cold can have half-a-quart of water mixed in with the oil over time. I do believe that thinner oils may carry away these compounds a bit faster on a cold morning, though I doubt there is much difference between a 5W-20 or 5W-30 either way...

I have noticed a significant improvement in cold starting with the M1 0W-20 AN I installed after dumping the M1 0W-30 AFE. But the AFE did look a bit dark and may have done some cleanup so hard to make any conclusions...
 
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Something no one ever seems to acknowledge here is that the majority of wear is at start-up and has nothing to do with whatever the oil is and more to due with the combustion process dumping acidic compounds and even water into the sump to the point that cars short tripped and idled excessively when cold can have half-a-quart of water mixed in with the oil over time. I do believe that thinner oils may carry away these compounds a bit faster on a cold morning, though I doubt there is much difference between a 5W-20 or 5W-30 either way...

I have noticed a significant improvement in cold starting with the M1 0W-20 AN I installed after dumping the M1 0W-30 AFE. But the AFE did look a bit dark and may have done some cleanup so hard to make any conclusions...
Agree. Its all our best guess these days without doing UOA and then each and every car oci has a unique set of circumstances. Good thing is we seem to have a never ending selection of products to choose from.
 
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Looking at couple of these graphs, and can't help but ask the question - How much difference is really there at full operating temperature? Having said that - I'm sticking with Porsche A40 approved oils in all vehicles I own and/or maintain.

View attachment 79382
Wear studies show a difference in wear over the small spectrum of HTHS viscosity, which only spans from about 2.6 to 4.0 cP. Seems like such a small difference in viscosity range wouldn't make a difference in wear, but it can.
 
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OK, now for the only “Thin Advocate”...

Ferrari manuals often recommend an ideal viscosity for operation. It is defined as 70 PSI at 6,000 RPM. It can be more or less but this is the ideal range. It is not defined as “at least” or “a minimum of”. Some manuals say a 5W40 should be good under all conditions while other manuals suggest the Shell Helix Ultra 10W60 for track use in high temperature environments. Note that the 60 grade oil is barely above a 50 grade off the shelf and rapidly thins with use.

Millions of cars and trucks, in all environments and conditions, have been using 20 grade oils for decades now with no adverse effects. Personally I cannot understand why people would insist on using a thicker oil than needed resulting in less power and reduced fuel economy.

Everybody seems to think bearing wear is the limiting factor for engine longevity. I believe it is piston ring wear in a properly maintained engine. I had a discussion with one of the leaders in lubrication research about this very issue:

Ali,

Thanks for the note. I've seen these slides before, but unfortunately I've never seen it presented live to be able to ask questions. I guess that the argument is that this is a starved lubricant condition, and the low vis oils have a higher flow and a better chance at getting to the ring/bore surface, even though they would provide lower film thickness in a fully flooded condition.

Film thickness is probably not the issue at top ring reversal, where we're always in boundary lubrication anyway. But, oil starvation would be an issue. Anything that promotes getting lubricant to the contact will be beneficial for maintaining the antiwear films. Unfortunately, too much lubricant at the top ring causes increased oil consumption. So, there's always a balance between too much and too little oil. This can be influenced by oil ring tension and cylinder bore finish as well as oil viscosity.

Regards,

Eric

Eric W. Schneider

I do believe that the engine manufacturers design power plants and matching oils to be useful in any encounterable circumstances. However, you can go up or down a grade if you need to fine tune for your specific application. As I do not track cars any more I always use a grade (or two) lower as pressure/RPM values allow for it.

Regarding cold starts. First of all this is defined as anything less than a fully warmed up engine. Here in Florida it is usually around 70 - 80F in the AM. Eric Schneider has shown that test engines under load will warm the oil up to the normal operating temperature during a 15-20 minute period. Engine wear decreases linearly as the oil warms (and thins). And this is in an engine starting at 75F. To further show that viscosity matters he artificially cooled only the oil back down to 75F and the wear linearly increased back to the highest level again.

To me, this indicates that we should always use the least thickening oil during the start up period. I go for the proper, indicated grade (usually a 20 or 30). Then use the least thick oil viscosity at start up, preferably a 0W and sometimes a 5W-...

As it turns out millions of cars running today and oil testing has shown that it does not matter what you use. Your engine will likely outlast the rest of the car or truck. So why not just use an oil that gives you more power and MPG. I have never heard a person complain about having too much power and that they would prefer to slow down their engines response.

Finally I have some data (though some will say it is not enough to be worth a look) to suggest that thinner oils in high power engines result is less wear. From an older post:


“If Ferrari specifies 5W-40 oil, why are you so interested in trying something like 0W-20? Do you believe the thinner viscosity will improve performance?”

Ferrari recommends oil based on the car being on a race track. A 20 grade oil running around town is thicker than a 40 grade oil running at wide open throttle on the track using all 800 HP. As oil takes around 20 minutes to warm up to the operating temperature while driving around town it is almost always thick as honey. Most trips are for me less than 30 minutes long. Hence the oil is even thicker yet.

I have demonstrated that these Ferrari engines have less wear running lower grade oils around town than the specified oils. Yes the results are of a small sample but they all show the same tendency. Oils less honey like will allow for more power, more fuel economy, less start up wear, running at higher RPM sooner, et cetera. My current 812 Superfast has sump temperatures of 165 - 175 F as I drive around town. What am I using at most - 100 HP? 200 HP? Certainly a 20 grade oil around town is way more viscous than a 40 grade oil while racing at the Sebring track using all 800 HP for 30 minutes.

Here is some data from older posts:

It may be worth revisiting this old UOA (used oil analysis) comparison. I am giving evidence that thinner oils can be used when otherwise very heavy grades may be specified. And that thinner oils may result in much less wear than when the “recommended” oil, in the “manual” is used.

Several things to note. We are neighbors, drove the same car (but for the milage), drove the same way in the same environment. His car had what can be considered normal wear. Yet mine had a significantly reduced wear pattern. Also, the original RLI that dropped to a 20 grade oil had more wear than the newer “Enzo” formulation. But it was still less than the 60 grade Shell oil. Maybe the sweat spot for this car was a 30 grade oil for driving in our environment.

Compared Enzo Ferrari UOA from years ago: This is my neighbor’s 2003 Ferrari Enzo with a total of 8,800 miles on the left column and my 2003 Enzo with a total of 4,400 miles on the right column (middle 2 columns, earlier UOA of my car). Both cars had about 1,400 miles on the oil. His obviously had more break-in time. He had the oil changed by the Ferrari dealer using the required 10W60 Shell Helix Ultra Racing oil. I ran 0W30 Castrol GC in the second column, the original formula of RLI in the 3rd column and the “new and improved “ RLI “Dr. Haas” Enzo formula in the last column.

Tested my Enzo oils by Terry Dyson. His testing counts larger particles as well as all the smaller ones so other labs may give false lower values. At no time has the oil temperature in this engine gotten above 180 F. This latest oil has been in for nearly two years but Terry Dyson said I should just keep going (and going and going). What is particularly interesting is that the original RLI formulation dropped to a 20 grade, the newer formulation did not.

Part of the original post: I believe this formulation has been perfected and am considering it’s use in all my cars. I am not sure my wife will allow such a thick oil in her Murcielago however.

OILS: ….....Shell.... GC….RLI….RLI - “Dr. Haas Enzo Formula”
Iron___________ 32...11...7...3 (Fe in RLI VOA =2)
Chromium ____ Nickel _________2...1....0...0
Aluminum _____11...3....2...0
lead _________ 16...0....3...1
Copper _______25...8....4...3
Tin __________ Silver ________ Titanium _____ Silicon ________ 7...3....4...2
Boron ________ 1...3...16..17
Sodium _______ 8...3....10...8
Potassium ____ Molybdenum _ Phosphorus ___1026...935…1032…698
Zinc _________ 1135...1228…1055...988
Calcium ______ 1454…167...2108…1898
Barium ______ Magnesium __1219...526…53...19
Antimony ____ Vanadium ____ Fuel %Vol ____ Flash_______not done..335..320..300
Abs Oxid _____ 34...10..127...95
Abs Nitr ______ 11....8....8....7
Wtr %vol ____ Vis CS 100C __ 15.8....11.8….8.6….9.8
Vic CS 40C___not done…66….44….48
SAE Grade _____40....30....20....30
Gly test ______NEG…..0.37 “not antifreeze”…...0…..0
TBN _________not done...7.9....5.9...6.4
TAN _________not done...1.7....1.4...1.3
Visc Inde x___ not done…154...177...192
Soot_________not done...0....0.01....0

Note that the Enzo engine that specifies a 60 grade oil had very little wear while running a 20 grade oil. But again, no use of all 650 HP. It’s just not possible driving in normal conditions. While running at 8,000 RPM and using all 650 HP may require a 60 grade oil, driving around town does not. I believe based on my own experiments that these cars are better off with oil grades more appropriate for urban driving as that is all I do these days. Though tempting and offered I have not raced for quite some time. Actually the last time I was on the track it was testing the soon to be released Maybach 57 and 62. Several professional racing drivers and I gave feedback to engineers from Stuttgart. ‘Quite a thrill. Several of my suggestions were done to the car. I eventually bought the original version then later the AMG version. Again, with some added Dr. Haas modifications.

Even Lamborghini tried to get my wife and her car on the track to no avail. It was enough for her to sip some wine with Valentino Balboni in our own garage.

Ali
I would like to see this same test done with different weights of the same exact brand of oil, to see what the differences in wear metals would look like, vs different weights of different brands of oils since add packs are so different among the brands.
 
Wear studies show a difference in wear over the small spectrum of HTHS viscosity, which only spans from about 2.6 to 4.0 cP. Seems like such a small difference in viscosity range wouldn't make a difference in wear, but it can.
Bunch of debates between 2.6-3.2
 
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