Shear ?

[edyvw]

The diesel fuel goes cloudy at about 5°F because it has large amounts of paraffin in it. Motor oil also contain paraffins to some degree. Even oils can withstand much lower temp. than diesel fuel - paraffins are paraffins.

Well, I started the diesel engine here at -42 after the car spent a night outside in the parking lot, with no block heater, with Valvoline MST 5w40 in the sump.

 

[CleanSump]

Oh golly. Crayons in my sump.

 

[kschachn]

VII absence doesn’t make an oil monograde. A monograde is any oil that simply didn’t pass the “w” tests, either because it couldn’t pass or because it was never tested. An oil might have no VII because it’s monograde, but it’s not monograde because it has no VII. The causality runs only one direction.

That’s exactly the definition in SAE J300. A multi-viscosity oil with VII could also fail to pass the requirements you list. Conversely a no-VII (Newtonian) oil can pass the multi-grade requirements and be labeled as such if the blender decides to do so. So it’s hinging on the presence of the VM, not the performance. No oil with polymeric VII may be labeled as a monograde.

 

[kschachn]

How your oil pump will suck air when the oil quantity is the same for both summer and winter?

My biggest concern is how easily a thicker oil (even it can be poured at certain temp.) will go through the pick up strainer, paper oil filter, VVT strainers and any other small passages inside the engine.

Both water and honey are pourable at 40F. Guess which one is flowing faster hence pumped better.

Because you don’t understand the same thing that resulted in damaged engines back in the ‘80s. When oil is rapidly cooled it can gel in the vicinity of the pickup tube and fail to be pumped. This led to discovering the misunderstanding that existed in the assignment of winter ratings and resulted in several changes to SAE J300.

It’s not about which one flows faster and “pumped better” nor is it about “passages inside the engine”. It’s about which one will pump at all. Once it gets to the pump it will flow. You’re falling for the simplistic understanding that ruined engines 45 years ago.

 

[OVERKILL]

VII absence doesn’t make an oil monograde. A monograde is any oil that simply didn’t pass the “w” tests, either because it couldn’t pass or because it was never tested. An oil might have no VII because it’s monograde, but it’s not monograde because it has no VII. The causality runs only one direction.

As @kschachn noted, that's incorrect. An oil with no VII polymer can either be labelled as the SAE grade it falls into, or, as a multi-grade with a Winter grade included. On the other hand, an oil that contains VII polymer must be labelled as a multigrade.

AMSOIL famously sold an SAE 30 that was actually a 10W-30. They chose to label it as an SAE 30 because that was the market they targeted. This is permitted under J300 for any oil that doesn't contain VII polymer.

 

[CleanSump]

As @kschachn noted, that's incorrect. An oil with no VII polymer can either be labelled as the SAE grade it falls into, or, as a multi-grade with a Winter grade included. On the other hand, an oil that contains VII polymer must be labelled as a multigrade.

AMSOIL famously sold an SAE 30 that was actually a 10W-30. They chose to label it as an SAE 30 because that was the market they targeted. This is permitted under J300 for any oil that doesn't contain VII polymer.

I ran that Amsoil 30/10W-30 oil exclusively in a diesel Mercedes for 348k miles. I recall it was labeled as "Diesel and Marine" back in the '90s through 20 teens. I haven't purchased any since about 2010 so I don't know about today.

 

[Hohn]

As @kschachn noted, that's incorrect. An oil with no VII polymer can either be labelled as the SAE grade it falls into, or, as a multi-grade with a Winter grade included. On the other hand, an oil that contains VII polymer must be labelled as a multigrade.

AMSOIL famously sold an SAE 30 that was actually a 10W-30. They chose to label it as an SAE 30 because that was the market they targeted. This is permitted under J300 for any oil that doesn't contain VII polymer.

Good to know the rules work differently than I thought. Thanks.

 

[Hohn]

Well, I started the diesel engine here at -42 after the car spent a night outside in the parking lot, with no block heater, with Valvoline MST 5w40 in the sump.

MST? You have a way back machine?

 

[OVERKILL]

Good to know the rules work differently than I thought. Thanks.

No problem

 

[edyvw]

MST? You have a way back machine?

Had 2013 BMW X5 35d.

 

[Hohn]

Well, I started the diesel engine here at -42 after the car spent a night outside in the parking lot, with no block heater, with Valvoline MST 5w40 in the sump.

My Dad's primary experience with diesels was owning his 1982 Rabbit with the manual trans. That thing spent almost all ND winter tethered to the electrical cord.


My orders to Hawaii (and can't take truck with me) meant that I had given him my truck for the duration of my Hawaii assignment. When the truck started at -24F with no block heater (and massive aftermarket injectors), he was quite gobsmacked.

Of course, the huge injectors meant a white haze that took quite awhile to go away under such conditions.

Ah, fun times.

I miss the old lumber wagon sometimes, 1990s Chrysler design and all of that notwithstanding.