Thinner oils wear more the engine at startup Proof

[Darwin1138]

Probably a little late to the party and slightly off topic now, but I just want to make a comment on this post.

On the audio we have a discrete point on both tracks, which is when the lifter noise quiets down; this noise quiets down when one or more conditions are met inside the engine like oil flow or oil pressure, it really doesn't matter what makes the noise go away; what is important is that this noise only appears on a totally cold engine and that it is linked to the viscosity of the oil.

Now the noise lasts 4.652 s with the 15W-40 since startup and only last 1.825 seconds with the 5W-30. So we can say that the thicker oil took 2.5 times more to meet the conditions to prevent noise in the valve train.

Based on those facts we can extrapolate, and say that the thicker oil will always take 2.5 times more than the thicker oil to get to the engine components, allowing for 2.5 times more wear in every cold start.

This is just a first approximation but it leads us into the right direction, that thicker oils allow more startup wear than thinner oils.

This is the original post of that video.

 

[Darwin1138]

I don't know why you deleted your post but since I took the trouble to answer it I will post it anyways.

Do you know how old each oil was?
15W-40 one month 1200 km 5W-30 2 weeks 500 km

You have one sound track sample of each, how do you know it's repeatable?
Yes I have at least 3 recordings of each oil, cold and at operating temperature.
It always makes the same noise at cold startup

Do you know the exact conditions (atmospheric, environmental) for each sound track? Yes, I recorded it

Do you know if each soundtrack was recorded with the same equipment, same distance, same background noise?
Yes, don't you hear my dog in the background?

Do you know if the files were not processed in any way?
The first files are not processed, only in the second track they are filtered and in the third they are reversed.

Do you know where the noise is coming from?
No, I don't . But depends on the viscosity. If the sound lasted the same time with different oils then I would have to conclude that it is not oil related.

Do you know if the noise correlates to wear? If so, how much wear?
What I do know if that noise correlates to the speed in which the oil starts circulating in the engine and that speed correlates to wear.

Do you know if the same filter was used?
Yes, Purflux LS218

Do you know how long the engine sat unused before each start?
16 hours

A comparative test could be that you remove the valve cover of an engine and measure the amount of time it takes the oil to flow to a certain camshaft bearing, this time could be different depending on the startup temperature and viscosity. In this experiment I am only trying to measure that in an indirect way. And I can measure that the 15W-40 took 2.827 seconds more than the 5W-30.

 

[KrisZ]

I wanted to edit my post and somehow ended up deleting it.

In any case, the only thing that I would conclude from that "test" is that the thinner oil flowed better, which is pretty obvious.
How that correlates to wear and engine lasting longer or shorter is pure guess work.

 

[RISUPERCREWMAN]

I really thought that the engine was quieter with the 5W-30? Head Scratcher Don't see your logic here at all!

 

[aquariuscsm]

Video is also comparing a conventional to a synthetic. Of course a 5W30 synthetic is going to flow faster at cold temps than a 15W40 conventional. To make a fair comparison via viscosity,repeat the same test using a 5W30 synthetic vs a 0/5W40 synthetic,similarly if you were to compare a 10W30 synthetic to a 20W50 conventional.

Test in the video loses all credibility imo.

 

[virginoil]

Originally Posted By: CT8
Originally Posted By: Trav
Originally Posted By: virginoil
Holden recommends the 5w-30 grade for the old Build 3800 V6 in everyday driving in Austrlia but in the snow or extreme cold it recommends the 15w-40 grade.

Is the Holden / GM recommendation flawed ?

There is some truth to the OPs claim thinner oils do were more in certain conditions and climate.

A sound test to evaluate wear could be the ??


That sounds backwards to me. 15w40 dino was the most common oil in Germany for decades and the engines would be a real bugger to start in real cold weather.
Many wouldn't even turn over.
Synthetics and the move to 10wXX took care of that problem for the most part.
Takes more power to pump the oil .we agree.


Nope, no mis quote.

Checked Mobil DATATECK site for the Holden VY V6 3800 (2004) a 5w-30 grade recommended for everyday driving, but in the snow a thick 10w-40 grade is recommended.

Holden I recall reduced the everyday grade for driving to a 5w-30 but the recommended grade in the snow remained the same as when the recommended everyday grade was 20w-50.

Has fuel dilution got anything to do with it ?

 

[KrisZ]

Originally Posted By: Darwin1138


Do you know if the noise correlates to wear? If so, how much wear?
What I do know if that noise correlates to the speed in which the oil starts circulating in the engine and that speed correlates to wear.



How so? Are you assuming that parts are dry and have full metal to metal contact? If not, then the longer tapping sound doesn't automatically correlate to wear. All it could be is a chain tensioner coming up to pressure and removing slack from the chain, or a valve bucket. In those cases there would be no extra wear, unless you can prove to me that in those few extra second the oil residue and the anti wear additive layer are fully stripped down, leaving bare metat to metal contact. That is why I asked if you knew where the sound is coming from and how it correlates to wear.

Like I said earlier, all this test does is show that a thinner oil flows better that's about it.

 

[zray]

Originally Posted By: aquariuscsm
Video is also comparing a conventional to a synthetic. Of course a 5W30 synthetic is going to flow faster at cold temps than a 15W40 conventional. ........."


Just think about this for a minute.

Sure, it will pour faster if you are pouring it out of a bottle. But your oil pump is no bottle . It's a positive displacement machine that doesn't care what the h*ll the temperature is, or the viscosity either. It will pump the same amount per revolution regardless of the oils weight.

Now what happens to the next is a different story when it gets to the bearings. That where the oil pressure relief valve might come into play if the oil is too thick and pressure gets too high

Z

 

[aquariuscsm]

Originally Posted By: zray
Originally Posted By: aquariuscsm
Video is also comparing a conventional to a synthetic. Of course a 5W30 synthetic is going to flow faster at cold temps than a 15W40 conventional. ........."


Just think about this for a minute.

Sure, it will pour faster if you are pouring it out of a bottle. But your oil pump is no bottle . It's a positive displacement machine that doesn't care what the [censored] the temperature is. It will pump the same amount per revolution regardless of the oils weight.

Now what happens to the next is a different story when it get to the bearings. That where the oil pressure relief valve might come into play if the oil is too thick and pressure gets too high

Z


Absolutely! I totally agree. I run 10W40/20W50 year round :^) I just think the test in the video is a lil out of balance. I guess a better analogy would be making a video comparing a 0W20 synthetic to an SAE60 mineral. The video would be more pertinent if they were comparing a 5W30 synthetic to a 5W30 mineral.

 

[Gillsy]

Originally Posted By: zray
Originally Posted By: aquariuscsm
Video is also comparing a conventional to a synthetic. Of course a 5W30 synthetic is going to flow faster at cold temps than a 15W40 conventional. ........."


Just think about this for a minute.

Sure, it will pour faster if you are pouring it out of a bottle. But your oil pump is no bottle . It's a positive displacement machine that doesn't care what the h*ll the temperature is, or the viscosity either. It will pump the same amount per revolution regardless of the oils weight.

Now what happens to the next is a different story when it gets to the bearings. That where the oil pressure relief valve might come into play if the oil is too thick and pressure gets too high

Z
A positive displacement pump will pump the same volume be it dino or syn provided the substance to be pumped is viscous enough to flow to the pickup. I see that as the "fly in the ointment"

 

[Clevy]

Originally Posted By: Gillsy
Originally Posted By: zray
Originally Posted By: aquariuscsm
Video is also comparing a conventional to a synthetic. Of course a 5W30 synthetic is going to flow faster at cold temps than a 15W40 conventional. ........."


Just think about this for a minute.

Sure, it will pour faster if you are pouring it out of a bottle. But your oil pump is no bottle . It's a positive displacement machine that doesn't care what the h*ll the temperature is, or the viscosity either. It will pump the same amount per revolution regardless of the oils weight.

Now what happens to the next is a different story when it gets to the bearings. That where the oil pressure relief valve might come into play if the oil is too thick and pressure gets too high

Z
A positive displacement pump will pump the same volume be it dino or syn provided the substance to be pumped is viscous enough to flow to the pickup. I see that as the "fly in the ointment"




Exactly.
A positive displacement pump moves the same volume of oil on every stroke no matter what viscosity. So the idea that a thinner oil flows faster is true if it's gravity fed but when being pumped a 20 grade moves just as fast as a 40 grade,the difference will be pressure.
Correct me if I'm wrong.
I will agree that a thinner lube is more desirable when cold if only to reduce drag.
I disagree that a 40 grade will increase wear at start up.
As we are coming to learn start up isn't the enemy,warm up is.
From what I've gathered cold oil will lubricate the bearings just fine. Wear increases when the oil is warm but not hot because the anti-wear agents haven't activated yet.
So thinner oil gives the bearing less of a wedge during the "not quite hot" phase of warm up.
Engine design,how it's operated and ambient are all contributing factors as far as wear is concerned and no broad stroke of any brush is the cure.
I use mos2 in my oil because it plates the moving parts and is a barrier during that all important warm up phase. Cera-tec is also great in this regard.
Just my opinion.

 

[Pontual]

Originally Posted By: Gokhan
OP has forgot that in addition to cold starts, idling is also very bad for your engine. Idling is bad because the oil film thickness increases with RPM. Speed and viscosity is what keeps moving parts from making metal-to-metal contact.

His main concern was that with thinner oil engine turns faster and this may result in more wear. On the contrary, slower the idle speed, more is the wear on the engine. You still don't want to race a cold engine over 3000 RPM but faster idle is actually better than slower idle as far as wear is concerned because the oil film between the moving parts will be thicker with more RPM.


No I didn't forgot that idle has minor oil pressure. But YOU forgot that at idle there's no load at the bearing - the part dependent on RPMs to make a hidrofilm ... unless you drive up hill at idle.

 

[zray]

Originally Posted By: Clevy
Originally Posted By: Gillsy
Originally Posted By: zray
Originally Posted By: aquariuscsm
Video is also comparing a conventional to a synthetic. Of course a 5W30 synthetic is going to flow faster at cold temps than a 15W40 conventional. ........."


Just think about this for a minute.

Sure, it will pour faster if you are pouring it out of a bottle. But your oil pump is no bottle . It's a positive displacement machine that doesn't care what the h*ll the temperature is, or the viscosity either. It will pump the same amount per revolution regardless of the oils weight.

Now what happens to the next is a different story when it gets to the bearings. That where the oil pressure relief valve might come into play if the oil is too thick and pressure gets too high

Z
A positive displacement pump will pump the same volume be it dino or syn provided the substance to be pumped is viscous enough to flow to the pickup. I see that as the "fly in the ointment"




Exactly.
A positive displacement pump moves the same volume of oil on every stroke no matter what viscosity. So the idea that a thinner oil flows faster is true if it's gravity fed but when being pumped a 20 grade moves just as fast as a 40 grade,the difference will be pressure.
Correct me if I'm wrong. ......."


You're not wrong.

But just to complicate things, I'd like to assert that there's huge difference between the claims of the "coating-type additives, such as MOS2, and actual operation. I'll go along with the advertising that they do coat the moving parts. What I don't buy is that the coating they provide makes a difference in wear. My own limited experience can hardly be viewed as a double blind scientific research, but a few 100,000's of miles of direct observation does have some value. The protection provided by a quality synthetic oil, Mobil 1 15w-50 in my case, is sufficient to forestall any measurable wear without the addition of anti-wear additives. I'm not saying my engines will never wear out. But they are wearing so slowly that it won't be in my lifetime?

Some common sense practices regarding engine warm up before putting a load on it, and Reasonable oil change intervals are key as well.

Z

 

[Shannow]

Originally Posted By: Pontual
No I didn't forgot that idle has minor oil pressure. But YOU forgot that at idle there's no load at the bearing - the part dependent on RPMs to make a hidrofilm ... unless you drive up hill at idle.


How do you ascertain that there's no load on the bearings at idle ?

Pistons are still going up and down 15 times a second.

 

[Gokhan]

Originally Posted By: Pontual
Originally Posted By: Gokhan
OP has forgot that in addition to cold starts, idling is also very bad for your engine. Idling is bad because the oil film thickness increases with RPM. Speed and viscosity is what keeps moving parts from making metal-to-metal contact.

His main concern was that with thinner oil engine turns faster and this may result in more wear. On the contrary, slower the idle speed, more is the wear on the engine. You still don't want to race a cold engine over 3000 RPM but faster idle is actually better than slower idle as far as wear is concerned because the oil film between the moving parts will be thicker with more RPM.

No I didn't forgot that idle has minor oil pressure. But YOU forgot that at idle there's no load at the bearing - the part dependent on RPMs to make a hidrofilm ... unless you drive up hill at idle.

Wear at idle has nothing to do with oil pressure. There are no pressure-lubricated (hydrostatic-lubricated) parts in the engine. Oil pressure has no effect on wear -- it merely helps to circulate the oil. Wear at idle results from low RPM, not low oil pressure, as lower RPM decreases the oil-film thickness.

For example, when the engine stops, bearings and crankshaft make contact. This is not because of lack of oil pressure -- it's because of lack of RPM. Increasing RPM decreases the wobbling of the crankshaft in the bearings and increases the oil-film thickness. This applies to other parts of the engine as well.

 

[Shannow]

^+1

 

[CarbonSteel]

So I have to ask--was there "official" proof anywhere in this thread? Did I miss it in between the bovine scatology or?

 

[Pontual]

Originally Posted By: Shannow
Originally Posted By: Pontual
No I didn't forgot that idle has minor oil pressure. But YOU forgot that at idle there's no load at the bearing - the part dependent on RPMs to make a hidrofilm ... unless you drive up hill at idle.


How do you ascertain that there's no load on the bearings at idle ?

Pistons are still going up and down 15 times a second.


Aham ...

 

[Shannow]

You missed a bit off your explanation...

If rod and piston weigh (say) 1KG, idle 900RPM, on a 3" crank, there's .3KN load on the bearing at TDC exhaust stroke...a little more than "nothing"

 

[spasm3]

Originally Posted By: Shannow
You missed a bit off your explanation...

If rod and piston weigh (say) 1KG, idle 900RPM, on a 3" crank, there's .3KN load on the bearing at TDC exhaust stroke...a little more than "nothing"


Plus the force of compression and subsequent expansion of the fuel/air mix also is transmitted to the bearing surfaces