0W-40 pros & cons...

[kschachn]

Originally Posted By: oil_film_movies
Can be a cool strategy:
1. Put M1 0w40 in your engine spec'ed for 0w20 or 0w30 on May 1.
2. Commit to a year (up to 15k miles) on the oil change interval.
3. By December, the oil will have likely sheared down to a 20 or a 30 weight, for winter.
Loss of the VII chemicals 6 months into the run wouldn't affect the cold 0w side much at all, as VII only pushes up hot visc.
Good base oils and anti-ox additives in M1 0w40 keep hot viscosity from climbing upward.

"likely"? Where is the evidence that this oil has ever sheared down to a 20 grade? In fact, the UOAs I've seen posted here show it stays in grade.

 

[dblshock]

...and all the peutred dilution, my goodness, especially on top that weak cafe add pack.

 

[dblshock]

I want to believe these oil companies make 0W-40 for a reason..it's probably a lot of trouble if 0/20 is always best.

for some reason I'm not understanding the 0W-40 marketing is weak.

 

[Trav]

Originally Posted By: Shannow
Designed specifically for thinner oils...

OK, Honda admit that they are making bearings bigger (length and diameter), while reducing oil clearances. This is the behaviour to increase minimum oil film thickness with thinner oils...aka they have reached the point where they can't go thinner on bearings.

Why are they doing this ?

Primarily to reduce the still comparatively massive piston/skirt frictional losses, by reducing viscosity.

This will decrease skirt drag, while increasing bearing drag, so there's an optimisation taking place.

So YES, Honda are designing engines for thinner oils.

But that's not an argument that these engines must exclusively use them. Per SR5, can't ever cold start them if 12Cst is going to damage an 8cst engine.


Shannow, you may be able to answer the questions that come to mind.

If the bearing clearances are smaller cold do they not get even smaller at operating temp? Would that explain how the xw20 engine can handle the higher cold viscosity and not the higher viscosity of the hot oil.

What about multi stage/variable oil pumps like the pendulum-slider that are becoming more common that can maintain pressure and flow of the thinner oils at operating temp?
Given the optimal pressure and volume these pumps provide is the film strength of the thinner oil similar when bearing clearances are reduced?

I am no thin oil guy but the manufacturers are claiming some of these new engines are designed with these oils in mind, I have no idea but if that's the case I have no problem with it.

 

[oil_film_movies]

Originally Posted By: kschachn
Originally Posted By: oil_film_movies
Can be a cool strategy:
1. Put M1 0w40 in your engine spec'ed for 0w20 or 0w30 on May 1.
2. Commit to a year (up to 15k miles) on the oil change interval.
3. By December, the oil will have likely sheared down to a 20 or a 30 weight, for winter.
Loss of the VII chemicals 6 months into the run wouldn't affect the cold 0w side much at all, as VII only pushes up hot visc.
Good base oils and anti-ox additives in M1 0w40 keep hot viscosity from climbing upward.

"likely"? Where is the evidence that this oil has ever sheared down to a 20 grade? In fact, the UOAs I've seen posted here show it stays in grade.


Stays in grade? Not M1 0w40 at 4k - 8k miles. Almost certain to shear to a 30 weight in that amount of miles.
Then, with the possibility of fuel dilution in a typical new DI-turbo or DI, expect a 20 weight could happen. Certainly the 30 weight is most likely of the two though.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4459585/Mobil_1_0W40_Euro,_4,000mi,_20
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3537007/Mobil_1_0w-40_-_6850_Miles_-_2
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4459924/2017_Focus_RS_-_Castrol_0W40_-
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2457954
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=3161668
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2483847
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2423345
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4546343/2016_Traverse_M1_0W40_5k_miles
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3775527/1

 

[kschachn]

So how many of those actually sheared out of grade? Two? Did any make it down to a 20 grade like you postulated?

The other thing is, with Blackstone no one really knows whether viscosity is due to fuel dilution or actual mechanical shear. Sonofjoe stated that viscosity loss due to mechanical shear of the VII is actually much less than what is typically thought. He said they are actually very stable. Wouldn't fuel related viscosity degradation be independent of the oil? Are you just saying that because M1 0W-40 starts off at the lower end of a 40-grade?

Plus some of those are over 5 years old, there is evidence the newer formulation is more stable.

 

[oil_film_movies]

Originally Posted By: kschachn
So how many of those actually sheared out of grade? Two? Did any make it down to a 20 grade like you postulated?

All did.
Do you know 12.5 cSt kv100 is a 40?
Want me to find more? Why don't you? Like all the question marks? Isn't that the way all your posts are????
As I said, add in DI or DI-turbos like Ecoboost or Honda Turbos like we've seen lately, and you'll be in the 20 weight area quickly with possible fuel dilution. Read my post again. Stop picking the 20 weight mentioned and concentrate more on the 30 weight stuff, as thats more likely between the two over a fleet.
Can you look up your own answers?

 

[Shannow]

Originally Posted By: kschachn
So how many of those actually sheared out of grade? Two? Did any make it down to a 20 grade like you postulated?


Only one that I've seen get there was the Joe Gibbs stunt...

 

[Shannow]

Originally Posted By: Trav

Shannow, you may be able to answer the questions that come to mind.

If the bearing clearances are smaller cold do they not get even smaller at operating temp?


Trav,
take a 1.995" steel bar in a 2.000" steel hole, and heat them, the clearances will stay the same at 0.005".
take a 1.995" steel bar in a 2.000" aluminium hole and heat them, and the clearances open up.

The heat in the bearings that the oil "carries away" is the heat generated in the bearing, and it flows from the oil film INTO the block and INTO the crank, meaning that at operating temperature, the temperatures in both components are about the same.



Iron crank/iron block, no change in clearance.
Iron crank alloy block, they open up.

 

[Shannow]

Originally Posted By: oil_film_movies

Do you know 12.5 cSt kv100 is a 40?


do you know that 12.499 is a 30 ???

 

[PimTac]

I still want to hear a plausible explanation how reducing the amount of oil in the sump will reduce drag. That CRV of dblshock has a very small capacity sump anyway. 3.5 qts?? So how much? 1/2 qt? 1qt?

“The World Wonders”. (How many here know where that phrase came from?)

 

[aquariuscsm]

I'd think a tiny bit more would be better than a tiny bit not enough

 

[Shannow]

Originally Posted By: PimTac
I still want to hear a plausible explanation how reducing the amount of oil in the sump will reduce drag. That CRV of dblshock has a very small capacity sump anyway. 3.5 qts?? So how much? 1/2 qt? 1qt?


splash lubricated it would, but you don't see that much these days.

In gearboxes and diffs, running them low reduces parasitic drag (by a little)

 

[PimTac]

Originally Posted By: Shannow
Originally Posted By: PimTac
I still want to hear a plausible explanation how reducing the amount of oil in the sump will reduce drag. That CRV of dblshock has a very small capacity sump anyway. 3.5 qts?? So how much? 1/2 qt? 1qt?


splash lubricated it would, but you don't see that much these days.

In gearboxes and diffs, running them low reduces parasitic drag (by a little)




Maybe run a thinner oil? gasp 8-o

 

[Patman]

Originally Posted By: dblshock
If your speced for a CAFE 0/20 and concerned for drag friction vs. wear just short fill it with 0/40 like 1/8" lower than you would otherwise.
...double protection with even less friction drag.


Double protection? Why not just run 10w60 and get triple the protection?

 

[Inspecktor]

Originally Posted By: PimTac
I still want to hear a plausible explanation how reducing the amount of oil in the sump will reduce drag. That CRV of dblshock has a very small capacity sump anyway. 3.5 qts?? So how much? 1/2 qt? 1qt?

“The World Wonders”. (How many here know where that phrase came from?)
Question to Admiral Halsey from Pearl Harbor as to whereabouts of Taffy 3 after he took off on a wild goose chase and left jeep carriers and destroyers to face the Japanese Navy.

 

[PimTac]

Originally Posted By: Inspecktor
Originally Posted By: PimTac
I still want to hear a plausible explanation how reducing the amount of oil in the sump will reduce drag. That CRV of dblshock has a very small capacity sump anyway. 3.5 qts?? So how much? 1/2 qt? 1qt?

“The World Wonders”. (How many here know where that phrase came from?)
Question to Admiral Halsey from Pearl Harbor as to whereabouts of Taffy 3 after he took off on a wild goose chase and left jeep carriers and destroyers to face the Japanese Navy.



Winner Winner Chicken Dinner.

 

[Panzerman]

Most people are going to use whatever that manual says.
They will never step back and look at it or have any real world experience with such things. The rest will think outside the box and realize light oil/ cafe standards and smaller passages with tighter clearances are total nonsense.

 

[Panzerman]

I put my money where my mouth is too. I drive a truck under warranty spec'd for 5w20 on the cap and manual with 5w30 or mostly 10w30 since it was new. It's still under warranty until 2077 ( Lifetime) I will continue to use 10w30 without issue.

 

[Dyusik]

Originally Posted By: SR5

So if a modern engine isn't designed to run well on a 40 grade at full operational temperature, then how does it run on a 20 grads at below 0F (-20 C) ?


That right there.