Would you sacrifice engine life......

[tig1]

Originally Posted By: RPMster
Seems pretty simple to me:

1) Use 20 weight oil, drive gently, get better gas mileage with practically immeasurable wear over the life of the vehicle.

2) Use 30 or 40 weight oil, drive it like you stole it, get poor gas mileage, and get better wear protection vs. 20 weight oil.

3) Use 20 weight oil, drive it like you stole it, still get poor gas mileage regardless, and get guaranteed increased wear over the life of the vehicle (compared to using 30 or 40 weight oil).

Why does this need to be complicated?


Your points 2 and 3 are wrong.

 

[tig1]

Originally Posted By: buster
Originally Posted By: NHGUY
I wonder about Mazda SkyActiv engines.Bearings are smaller,less drag on rings...I want to see one at 150K miles that isn't pushing oil or knocking.


I have almost 19,000 miles on a 2015 Mazda 3. I've been using Mobil 1 0w20 EP. I am changing it out this weekend and going with 5w30.


Why is that?

 

[stchman]

OK, this thread is going down a rabbit hole.

People act like if 0W-20 is used the engine will fly apart when 5W-30 will protect the engine for 800K miles no problem.

 

[Garak]

Originally Posted By: Vikas
Can you explain this better? I mean if you are going to claim "water is not wet", you do have to give little bit more rigorous explanation than brushing it off saying "feel" is often wrong.

Look at some Stribeck curves. Also, note that a friction modifier is not the same as an anti-wear compound. In some of the subforums, there have been in depth discussions on this very matter. Mola has posted extensively on these matters.

 

[Greasymechtech]

I do not want to sacrifice engine life for MPG.

I do believe that an engine can be engineered for thinner oils.

I also believe that automaker R&D is not as good as many think.

I will stick with HTHS and/or higher additive levels.

 

[Vikas]

OK, I am game. I glanced at the website discussing Stribeck curve. Please tell me where is the comparison of the friction with and without the lubrication.

"From practical experience, we know that adding a lubricant to a solid-solid contact will significantly reduce friction. The reduced friction leads to less wear, heat generation and energy loss – all of which reduce operation costs and downtime. "

Nothing in the document tries to giver counter argument to the above starting paragraph. Remember, you guys are claiming "less friction means high wear" and providing Stribeck curve as a proof. The curve says nothing of that sort.

 

[Shannow]

Originally Posted By: Vikas
OK, I am game. I glanced at the website discussing Stribeck curve. Please tell me where is the comparison of the friction with and without the lubrication.

"From practical experience, we know that adding a lubricant to a solid-solid contact will significantly reduce friction. The reduced friction leads to less wear, heat generation and energy loss – all of which reduce operation costs and downtime. "

Nothing in the document tries to giver counter argument to the above starting paragraph. Remember, you guys are claiming "less friction means high wear" and providing Stribeck curve as a proof. The curve says nothing of that sort.


It's not an "extraordinary" claim if you've read at least one textbook produced in the last 60 years.

Stribeck to the right is full film, "zero wear", to the left is contact (wear). The bottom axis is RPMxViscosity/Load.

More viscosity, more parts separation, and more hydrodynamic drag.

Follow that line down to the minimum friction point, and it's clearly not zero

Traditionally, the high friction on the left was as a result of contact, and high wear.

Friction modifiers being introduced has lead to the lower part of the curve, where friction can be slightly lower during partial contact.

That friction reduction is caused by the additives forming something like a "soap" with the parent metal, and that "soap" being removed.

It's vastly lower wear than the un friction modified case, but clearly more than full hydrodynamic, as the parent metals are being consumed.

 

[Benito]

never mind!

 

[Shannow]

Originally Posted By: Joenpb
Because your theory is likely incorrect. If 20w oil was designed to have optimum flow through the cam, a heavier oil won't flow as well leading to more wear.

Back up your claim with a UOA, otherwise its just as likely to increase wear as prevent it. Each engine is different, what was good for one, may not be for another.


Show me where thinner oils produce less wear on the industry standard sequence IV warm-up test ?

IF it's flow that does the lubricating, and IF the thinner oils give more flow, then clearly, their superiority will be demonstrated in this test, which is full, developed oil pressure, and operating at 140-150F.

Find a single study that shows an advantage of lower viscosity (only variable) in the industry standard warm up wear test.

Then explain why the API base oil interchange guidelines only allow you to bypass Sequence IVA if INCREASING the viscosity over the tested viscosity...clearly, they understand that a reduction needs further testing, an increase doesn't

 

[Vikas]

May be I am misunderstanding but did you or did you not make the claim that "lower friction could result in higher wear"? Nothing you have presented so far supports that claim. Are you saying that adding friction modifier lowers friction but adds more wear? Wear of the material being protected? Show me!

The chart presented says adding friction modifier reduces friction. I am not disputing it all all. Where is the "wear" variable on that graph showing it going up?

 

[Joenpb]

Quote:
Show me where thinner oils produce less wear on the industry standard sequence IV warm-up test ?


Say What?

Quote:
Because your theory is likely incorrect. If 20w oil was designed to have optimum flow through the cam, a heavier oil may not flow as well leading to more wear.


Better?

What I know is what I've found through UOA's. I was using Redline 5w20 which has a viscosity of a 5w30, and it produced a lot more wear metals than Pennzoil Ultra 5w20. Some 30w oils may flow fine, but probably not all, and to assume so so is...well we all know what they say about assume.

 

[Jetronic]

friction modifiers only work when there is metal to metal contact. the soap formed by the metal oxide and the friction modifier gets stripped under heavy stress, it's not as durable as the zddp formed layer with high friction.

wear and friction are 2 completely seperate things. Wear is not on the stribeck curve, and can't be.

There are hundreds of studies about wear and/or friction reduction showing that they are not related. Friction reduction can lead to higher wear, or to less wear. There's no way to tell but test. furthermore, both the achieved friction reduction and wear depend also on the metals in use. Even the slightest difference in composition can change the results.

 

[Shannow]

Originally Posted By: Joenpb
What I know is what I've found through UOA's. I was using Redline 5w20 which has a viscosity of a 5w30, and it produced a lot more wear metals than Pennzoil Ultra 5w20. Some 30w oils may flow fine, but probably not all, and to assume so so is...well we all know what they say about assume.


And you assume that these high metals were caused by "flow" ???

 

[3311]

I will consider thinner oils when I can actually measure the economy gains myself.

 

[omegaspeedy]

This has been a long thread of of many opinions for and against low viscosity oils (some backed up with scientific papers).

So should we run a full synthetic 5W40 or an 0W20 (mild conditions) in a modern 2.0L Variable Valve Timing Cam engine to MINIMISE WEAR. I don't give a rats [censored] about fuel economy. The user manual states both are acceptable.

Still fully confused...

 

[Justin251]

Ok. So my hemi specs 5w20 and nothing else. My hyundai specs 5w20, 5w30, and 10w30.

I guess they are gonna fall apart from me using 20 weights.

 

[Shannow]

Originally Posted By: Justin251
I guess they are gonna fall apart from me using 20 weights.


Nope, that's the usual "thin oil" strawman that pops up in all these threads.

Please find anyone in the thread who has suggested
* falling apart;
* exploding;
* pile of failed engines on the highway.

(all parts of the meme).

 

[expat]

Originally Posted By: Justin251
Ok. So my hemi specs 5w20 and nothing else.



So I see that you run 0w-20 in it!

In Alabama!

 

[Justin251]

Originally Posted By: expat
Originally Posted By: Justin251
Ok. So my hemi specs 5w20 and nothing else.



So I see that you run 0w-20 in it!

In Alabama!


Buck a quart is the primary reason. lol

And it being interchangeable.

 

[Joenpb]

Originally Posted By: omegaspeedy
This has been a long thread of of many opinions for and against low viscosity oils (some backed up with scientific papers).

So should we run a full synthetic 5W40 or an 0W20 (mild conditions) in a modern 2.0L Variable Valve Timing Cam engine to MINIMISE WEAR. I don't give a rats [censored] about fuel economy. The user manual states both are acceptable.

Still fully confused...


Use each for an OCI and do a UOA on both, then make your decision based on fact/wear, as opposed to unsubstantiated claims. Good luck.