Another xW20 vs xW30 thread

[Rvin]

Hello all,
I hope y'all doing fine.
So first of all, I've been a long term reader of this forum but I've never participaited in the topics so you can treat me as a long-term member (just joking)

So, as the topic header implies it's gonna be another discussion regarding "thick" vs "thin" oil and you might be wondering that this subject has been discussed for ages, why this guy's asking it again? Yes you are right. However, the problem is that in none of those topics a satisfactory consclusion has been made/provided. So I opened this again to settle this arguement once and for all with the help of knowledgeable people here.

Alright, the main question is: which one provides better protection against wear and tear?
xW20 HTHS>=2.6
xW30 HTHS>=2.6
In general, thick vs thin (I'm talking about oil BTW)

Throughout my journey in BITOG, I've read so many interesting post and papers provided by some of the best in this entire forum, but like I said before none of those topic have come across a singular, "all-agreed" conclusion.
What I'm doing now is categorizing all those subheadings related to this subject (mainly paradoxes in my mind) to make the conversation flow more coherent and accurate

So let's start with the first paradox

1-HTHS vs HTFS:
From what I gathered from all the posts around, it seems that in some critical points in the engine the shear rate far exceeds the 10^6, in which the HTHS doesn't provide any info about that and it's down to HTFS, which unfortunately there is zero to none info available publicly. It has been argued that thinner oils (mostly) are more stable above 10^6 compared to thicker oils (again, mostly) and I totally understand that this phenomenon is related to VII, base oil, additive packages (EP, AW, DDI etc.).
So here is the first paradox: if the above menetioned is true, can we argue that thinner oil provides better wear protection compared to thicker oil?

2-Shear rate (again) and oil temp:
It is understood that as the RPM increases the oil temp increases as well, hence the oil will be more prone to breakdown thus less protection.
However, there is another problem in my head: we all know that higher RPM doesn't always equal to higher load. In nowadays cars (mostly auto boxes) the gearbox upshifts as soon as it could so you end up pressing the throttle more to move the car forward, meaning more load.
In this scenario, there would be a lot more stress on piston rings, especially on major thrust face and minor thrust face. I'm assuming that this leads to a significant increase in oil temp in these areas and shear rate will also increase regardless of the RPM.
Referring to the first arguement if it's (HTHS VS HTFS) is true, again, can we argue that the thinner oil provides better protection?

3-Contradicting studies and observations: here in BITOG and many studies and papers, it has been observed that the thinner oil USUALLY runs cooler and that in fact makes the oil less prone to lose its viscosity and film strength.

Now all the paradoxes were spoken let's focus on some actual undeniable facts:

1-Thinner oil, thinner MOFT: it is known that the thinner oil provides thinner film, therefore it can be argued that the thinner film is more prone to shear thus increasing the possibility of metal to metal contact!?

2-Studies that have proven thinner oils mean more wear: I believe no further explanation is needed for this.

So dear friends, as you can see all these 5 things I mentioned don't match up (at least in my head), that's why I posted here to ask for your opinions to shed some light on these matters.
I've tried to keep things as concise as possible. And just to let you know I'm not talking about putting xW20 or xW30 oil in an old 50's engine, no! I'm talking about pouring an xW30 oil for improving the protection in an engine where xW20 is originally recommended.

My aim is to gather all knowledgeable people here (again) to examine these ideas, either scientifically or emperically (or maybe both), even further in order to settle this arguement once and for all and please do not hesitate to go as technical as possible as it makes everything more clear.

In the end, I appreciate you all for reading the whole text and my apologies if you see any dictation or grammatical errors as English is not my first language.

 

[edyvw]

0W40.

 

[Urshurak776]

making in progress.

There is a reason there are so may threads. This one will be no different.

Yes, thicker oil will provide better film protection in long run. Doesn't mean a 20 weight won't be fine for a few hundered thousand miles. CAFE is the reason manufacturers use these oils, not for engine protection.

 

[kschachn]

Joined today, starts yet another thick vs. thin thread and admits it’s been beaten to death already. What could go wrong?

And what “journey” have you been on with Bitog? Aren’t you new here?

 

[Rvin]

making in progress.

There is a reason there are so may threads. This one will be no different.

Yes, thicker oil will provide better film protection in long run. Doesn't mean a 20 weight won't be fine for a few hundered thousand miles. CAFE is the reason manufacturers use these oils, not for engine protection.

I appreciate your response.
However, on each and every one of them there is no "one and only" conclusive conclusion.
And if you read my post a little bit more carefully (while enjoying your popcorn) you can clearly see I seek to examine all those mentioned paradoxes to achieve a definitive answer

 

[Rvin]

Joined today, starts yet another thick vs. thin thread and admits it’s been beaten to death already. What could go wrong?

And what “journey” have you been on with Bitog? Aren’t you new here?

Yes indeed
Joined today and I don't see any problem with that
And if it's beaten to death I couldn't manage to find the body. If you can show me where the body is buried, I will delete the whole thread
Satisfied?

Oh btw, you asked about the journey. As far as I know most threads are open to non-members so I believe I can be reader for many years while not participating.

If you are willing to provide any useful information, that's sound. But if you want to act out of manners, I'm afraid that we cannot reach to a proper conclusion.

And now this explains exactly why on millions of other threads the conversation led to nowhere because out of 14 pages I doubt it will be more than 1 page of useful conversation, which are mostly provided by Shannow, Molakule, and Overkill.

 

[JavierH19]

xW30 HTHS>=2.6

Forgive me Bob for I cannot resist the urge to partake in this thickie thin as onlookers munch their

30 grades have a minimum of 2.9 but the majority I've seen are 3.1 but sometimes 3.0 or 3.2. This is for non European labeled oils of course. Euro oils are almost always going to be 3.5 hths minimum and have a more robust additive pack as well.

Many papers have been published showing timing components benefit the most from thicker oil but most engines have become better designed for thin oil than before as fords and other brands calling for a 20 grade two decades ago struggled with wear issues in the long run and did benefit from thicker oil. But something like a Toyota that runs on 1.8 hths 0w-8 likely won't see the benefit of a 3.5 hths oil like how old studies were published. Though I would still use something closer to 3.0 hths in one and in those engines that spec for 0w-8 as the minimum the maximum you can use is 10w-30 so no engine is locked to only one viscosity. One issue that I have is the use of temporary coatings which will wear away. I know bmw and other manufacturers are using coatings on parts like bearings to reduce friction and specify a thinner oils like 0w-12 as a quick and dirty way to get away with lowering epa fines but once the coating wears after the warranty and you keep using thin oils you'll see accelerated wear and symptoms like chain rattle and low oil pressure.

But hths isn't everything though it's the main component in reducing wear but the base stock itself and the additives can make a thin oil protect better than a thicker one. It's why very thin oils like 12 and 8 grade took so much development time and testing. I remember reading about how 8 grade was bad enough to where you got no fuel economy improvement and a lot more wear in the beginning but with more r&d they do provide more economy but not greatly increasing wear compared to a grade higher.

All in all this depends on the specific engine. Some engines really are designed for thinner oils and won't see much wear reduction in using a thicker oil though it never hurts to and at most you lose a few bucks on that insurance and some aren't and the manufacturer is just saving money on epa fines and saving on not investing in r&d in some cases.

 

[kschachn]

Yes indeed
Joined today and I don't see any problem with that
And if it's beaten to death I couldn't manage to find the body. If you can show me where the body is buried, I will delete the whole thread
Satisfied?

Oh btw, you asked about the journey. As far as I know most threads are open to non-members so I believe I can be reader for many years while not participating.

If you are willing to provide any useful information, that's sound. But if you want to act out of manners, I'm afraid that we cannot reach to a proper conclusion.

And now this explains exactly why on millions of other threads the conversation led to nowhere because out of 14 pages I doubt it will be more than 1 page of useful conversation, which are mostly provided by Shannow, Molakule, and Overkill.

Thanks, that confirms what I was thinking.

 

[Patman]

The type of use your car has also dictates if you will benefit from a 30wt over a 20wt. I often mention the fact that I drive my Civic very gently and I do 90% highway driving and longer trips (generally 50+ miles every trip I take with it) For me I really would not see any benefit going to a thicker oil and since I drive 35,000 km a year, every bit of fuel savings is important to me. So if switching to a 0w30 resulted in me spending even just $50 more a year in gas, that’s a steak dinner right there

 

[Glenda W.]

…..

 

[melk]

I run 30 weight on everything and don't give it a second thought.

¯\_(ツ)_/¯​

 

[Rvin]

Forgive me Bob for I cannot resist the urge to partake in this thickie thin as onlookers munch their

30 grades have a minimum of 2.9 but the majority I've seen are 3.1 but sometimes 3.0 or 3.2. This is for non European labeled oils of course. Euro oils are almost always going to be 3.5 hths minimum and have a more robust additive pack as well.

Many papers have been published showing timing components benefit the most from thicker oil but most engines have become better designed for thin oil than before as fords and other brands calling for a 20 grade two decades ago struggled with wear issues in the long run and did benefit from thicker oil. But something like a Toyota that runs on 1.8 hths 0w-8 likely won't see the benefit of a 3.5 hths oil like how old studies were published. Though I would still use something closer to 3.0 hths in one and in those engines that spec for 0w-8 as the minimum the maximum you can use is 10w-30 so no engine is locked to only one viscosity. One issue that I have is the use of temporary coatings which will wear away. I know bmw and other manufacturers are using coatings on parts like bearings to reduce friction and specify a thinner oils like 0w-12 as a quick and dirty way to get away with lowering epa fines but once the coating wears after the warranty and you keep using thin oils you'll see accelerated wear and symptoms like chain rattle and low oil pressure.

But hths isn't everything though it's the main component in reducing wear but the base stock itself and the additives can make a thin oil protect better than a thicker one. It's why very thin oils like 12 and 8 grade took so much development time and testing. I remember reading about how 8 grade was bad enough to where you got no fuel economy improvement and a lot more wear in the beginning but with more r&d they do provide more economy but not greatly increasing wear compared to a grade higher.

All in all this depends on the specific engine. Some engines really are designed for thinner oils and won't see much wear reduction in using a thicker oil though it never hurts to and at most you lose a few bucks on that insurance and some aren't and the manufacturer is just saving money on epa fines and saving on not investing in r&d in some cases.

Thanks very much for the information
However, I am assuming you have overlooked some other things I mentioned.

One of my problems is: HTHS addresses up 10^6 (if memory serves me right) and anything above that, which happens mostly around piston rings, cam lobes etc is out of HTHS's scope range. And here in BITOG it has been claimed that thinner oils provides more stability above 10^6 compared to xW30 (for example).
So the paradox is: if more stability above 10^6 shear rate for thinner oils is true, then it should be translated into "better protection"
Why it's not the case and how?
This is my question

 

[Triple_Se7en]

Rvin
For all we currently know, Edy's thought of 0w40 may be the best opinion.
Make - model - year and engine size of your vehicle please. That should help narrow the choices for you.

 

[Rvin]

Rvin
For all we currently know, Edy's thought of 0w40 may be the best opinion.
Make - model - year and engine size of your vehicle please. That should help narrow the choices for you.

Hello mate,
I was using 0W40 (Mobil 1 FS) in my previous car. But due to some financial difficulties I had to sell it and buy a daily driver Opel Astra 1.4 turbo with D14XFT engine.
Some sources suggest 5W30 dexos 1 gen 3
Some sources suggest 0W20 OV0401547 A20
Filler cap: Dexos 1 0w20
Owners manual: everything but xW40

 

[Triple_Se7en]

If you still have a stockpile of 0w40 from your prior vehicle and feel it's too thick for the Opel, you could blend some 0w20 or 0w30 with your leftover 0w40 until gone. For best results, buy from the same motor oil producer.
Cheers Mate.

 

[dnewton3]

So, as the topic header implies it's gonna be another discussion regarding "thick" vs "thin" oil and you might be wondering that this subject has been discussed for ages, why this guy's asking it again? Yes you are right. However, the problem is that in none of those topics a satisfactory consclusion has been made/provided. So I opened this again to settle this arguement once and for all with the help of knowledgeable people here.

You are fooling yourself if you believe that your thread will somehow usurp the hundreds (yes; hundreds) of others about this thick/thin topic. If you think you will "settle this once and for all", you're delusional; pardon those of us who are skeptical. Feel free to beat this horse to a pulp; you're not the first and won't be the last.

And if it's beaten to death I couldn't manage to find the body. If you can show me where the body is buried, I will delete the whole thread
Satisfied?

You not able to use the "search" function yourself? If you've been here lurking as long as you profess, then you should know that this topic isn't new, nor will it ever be "settled".
https://bobistheoilguy.com/forums/search/3832288/?q=thick+vs+thin&t=post&c[title_only]=1&o=relevance
And that's only using "thick vs thin" search terms. If you expand to "viscosity", etc, you'll end up with dozens of more pages.


Should I delete the thread for you now?

.

 

[JavierH19]

Thanks very much for the information
However, I am assuming you have overlooked some other things I mentioned.

One of my problems is: HTHS addresses up 10^6 (if memory serves me right) and anything above that, which happens mostly around piston rings, cam lobes etc is out of HTHS's scope range. And here in BITOG it has been claimed that thinner oils provides more stability above 10^6 compared to xW30 (for example).
So the paradox is: if more stability above 10^6 shear rate for thinner oils is true, then it should be translated into "better protection"
Why it's not the case and how?
This is my question

I won't be able to fully explain htfs as I don't fully know it but only to a degree so I'll point you to here. It has more to do with the specific type and amount of vii. Gokhan's post are the best.

Thread 'Would someone explain HT/FS?'

Sep 28, 2022

Or provide a pointer or a link to an explanation? Searched here and on Google with no results applicable to oil. Thanks so much.

• Shel_B
• Replies: 25
• Forum: Passenger Car Motor Oil (PCMO) - Gasoline Vehicles

 

[Rvin]

You are fooling yourself if you believe that your thread will somehow usurp the hundreds (yes; hundreds) of others about this thick/thin topic. If you think you will "settle this once and for all", you're delusional; pardon those of us who are skeptical. Feel free to beat this horse to a pulp; you're not the first and won't be the last.

Have you ever asked yourself why I'm not the first and wouldn't be last?

It is so wonderful how people have time to post sarcastic answers and somehow ridiculing, but don't bother themselves to answer at least one line (let alone a paragraph) with some useful information!

And do you mind if I ask you what do you mean by "skeptical"?

If the question I asked has been answered 100s of times, I would be glad if anyone points me to the right direction or at least bring up the "final answer" and this thread will be deleted.

And the thing is I've read most of them and if I could find my answer over there, would you please explain to me why I opened up another thread?

 

[dnewton3]

Have you ever asked yourself why I'm not the first and wouldn't be last?

It is so wonderful how people have time to post sarcastic answers and somehow ridiculing, but don't bother themselves to answer at least one line (let alone a paragraph) with some useful information!

And do you mind if I ask you what do you mean by "skeptical"?

If the question I asked has been answered 100s of times, I would be glad if anyone points me to the right direction or at least bring up the "final answer" and this thread will be deleted.

And the thing is I've read most of them and if I could find my answer over there, would you please explain to me why I opened up another thread?

You are missing the point.
This is a topic which has never seen any singular agreement to a definitive answer.
Your trolling arrogance is that you somehow think your thread is going to usurp all the others and find that elusive unicorn answer?

Locked.