Shear ?

[Exhaustgases]

In the latest LSJ video, facts about 0W-20 and 5W-30. I just find it funny that there is no mention that shear is mostly a multi grade oil problem.

There is a reason that the most expensive engines past and present, have always specified, single/ non multigrade oils.

He talks about the spread between the lower and higher numbers as the problem (my words). Of course more polymers are added to make the base oil make it to the upper number.

So am I close?

 

[kschachn]

In the latest LSJ video, facts about 0W-20 and 5W-30. I just find it funny that there is no mention that shear is mostly a multi grade oil problem.

There is a reason that the most expensive engines past and present, have always specified, single/ non multigrade oils.

He talks about the spread between the lower and higher numbers as the problem (my words). Of course more polymers are added to make the base oil make it to the upper number.

So am I close?

Not “mostly” but only. Monograde oils do not shear.

You’re close in a very general “I read it on the Internet so it must be true” sense. Not all VII are anywhere near the same, some are far more robust than others.

Add to the mix that few engines actually have a problem with mechanical shear of the VM. The vast majority of people do not have to worry about this if you are buying a reputable brand of motor oil. Most of what we see on here that is labeled as shear is actually fuel dilution. Concerns over shear are mostly a phantom worry especially at a reasonable OCI.

Which expensive engines are these that specify a monograde oil? Do you mean some industrial engines? That’s a very different application and not directly related to the automotive environment.

Ferrari, Porsche, Lamborghini, Mercedes-Benz, BMW, all have expensive engines and none of them specify a monograde oil. Not that it wouldn’t work if the temperature is correct, but they don’t specify it. Whether or not an engine would shear the VII is directly related to the design of the engine. You could have a cheap engine that would do a lot worse than a much more expensive one.

 

[altaylar]

What matters for the user is the loss of viscosity at the end of the day, which is essentially the sum of permanent VII damage + fuel dilution. From that perspective, monograde oil can loose viscosity as well, albeit slower. Though today more expensive, star shaped polymers too, which seems to be almost immortal for engine oil application. Some higher end oils use that, most notably HPL. (Well, they also have a mutligrade without VII).

I do not see why an "expensive" engine may spesifcy monograde oil today. First of all, there are fantastic multigrade oils, and the highest performance engines I am aware, including Ferrari's and AMG engine Aston Martin uses, call for a multigrade

 

[BMWTurboDzl]

There is a reason that the most expensive engines past and present, have always specified, single/ non multigrade oils.

Seems like a false premise.whicb leads to incorrect conclusions.

 

[Exhaustgases]

Which expensive engines are these that specify a monograde oil? Do you mean some industrial engines? That’s a very different application and not directly related to the automotive environment.

Most all ship engines multi million dollar units. Old large recip aircraft engines. Locomotive size engines etc.

 

[CleanSump]

None of those are comparable to a car, SUV, or pickup truck. Those all get a warmup and then run at pretty much a constant speed for long hours.

 

[TacoFergie]

Add to the mix that few engines actually have a problem with mechanical shear of the VM. The vast majority of people do not have to worry about this if you are buying a reputable brand of motor oil. Most of what we see on here that is labeled as shear is actually fuel dilution. Concerns over shear are mostly a phantom worry especially at a reasonable OCI.

This right here. I commented on the video specifically relating to this. He hardly mentioned the fact that viscosity loss could be contributed to fuel dilution as he primarily focused on mechanical shear. I'm not sure why that was omitted from the video as IMO the majority of viscosity loss in non-high performance modern engines is due to fuel dilution, not mechanical shear. His data from 10k used oil analysis showed that 5w30 is shearing at twice the rate of 0w20 oils. It makes me wonder how many of those 5w30 samples may be from people bumping up from their recommended 0w20 because of previous used oil analysis showing high amounts of viscosity loss with 0w20? It is common after all that people bump up a grade because their results are showing it will essentially end up being the correct grade by the end of the OCI.

For example, here is my Subaru Ascent showing multiple OCI's with major losses in viscosity. At the time I was one of the first few that had used oil analysis on the FA24DIT, so there wasn't many trends set. At first in my used oil analysis thread from a few years ago I was trying to figure out how it could shear out of grade so much thinking it was mechanical shear given Blackstone's low amount of fuel dilution. Then after lots of discussion, I was pointed towards OAI which showed exactly where the viscosity loss was coming from. Fuel dilution is very common on the FA24DIT, especially more so in winter months as my wife uses the remote start quite frequently.

1. 0w30 Mobil AFE (winter months)
2. 0w30 Mobil AFE (winter months)
3. Castrol EDGE Extended Performance 0w20

I haven't done any used oil analysis since the last one listed on the OAI sheet. I figured I set a trend and just won't go over 4k OCI's. I've got 75k currently on the vehicle, been running the Castrol Edge Extended Performance 0w20 since I got a bunch of jugs for super cheap. Most recent change at 73k I used Valvoline Restore and Protect 0w20 and the next change will be Valvoline Restore and Protect 5w30 based off some discussions in some other threads. I may do a couple more used oil analysis at some point just to see how things are going.

 

[Exhaustgases]

None of those are comparable to a car, SUV, or pickup truck. Those all get a warmup and then run at pretty much a constant speed for long hours.

I'm not sure when I started using a multi grade, it may have been in the early to mid 90's, maybe it was later will ask a friend that may remember it. The oil was always conventional SAE 30 in all vehicles I had at the time. This was year round, some winters cold enough to freeze over 1 foot thick on a small local lake. And just like the old airliners that ran straight 60, that thick oil remains on the parts and acts like the prelube or similar to assembly lube. Never ever had problems from it, yeah real cold would slow the cranking a bit.
I do know of one engine that I would not do that with now though, yeah a Ford

 

[altaylar]

None of those are comparable to a car, SUV, or pickup truck. Those all get a warmup and then run at pretty much a constant speed for long hours.

I don`t know what oil they are using, but I have seen some dodge track cars getting their oil warmed up before getting on the track on a luxury car rental for track event.

A passenger car oil must be "idiot proof" to a degree, and multigrade is just perfect for that. And technology being where it is right now, I don`t really see a good reason going with a stratight grade.

 

[kschachn]

I'm not sure when I started using a multi grade, it may have been in the early to mid 90's, maybe it was later will ask a friend that may remember it. The oil was always conventional SAE 30 in all vehicles I had at the time. This was year round, some winters cold enough to freeze over 1 foot thick on a small local lake. And just like the old airliners that ran straight 60, that thick oil remains on the parts and acts like the prelube or similar to assembly lube. Never ever had problems from it, yeah real cold would slow the cranking a bit.
I do know of one engine that I would not do that with now though, yeah a Ford

Right.

 

[edyvw]

Most all ship engines multi million dollar units. Old large recip aircraft engines. Locomotive size engines etc.

Which one of those you have under the hood?

 

[4wd]

CAT C280-16 - 15W-40 Mobilgard

 

[Japanese]

There is a reason that the most expensive engines past and present, have always specified, single/ non multigrade oils.

You cannot use single grade oils in temperatures below 32°F in a car engine. So only this thing makes them not usable, not only in modern cars, but in any cars, even those from 50 years ago.
Matter a fact you cannot use single grade oils below 32°F in other civil equipment too (motorcycles, garden equipment, ect.)

 

[Exhaustgases]

You cannot use single grade oils in temperatures below 32°F in a car engine. So only this thing makes them not usable, not only in modern cars, but in any cars, even those from 50 years ago.
Matter a fact you cannot use single grade oils below 32°F in other civil equipment too (motorcycles, garden equipment, ect.)

That is all dad ran in any and all cars or trucks we had, and here in this state from the early 1950's till ? And like said many many below 32 deg F days in winter months.

And sorry to say but in dirt machines I worked with in the 70's through the early 2000's all we used in the old dozers was single grade 30 series 3 oil, and it was in every compartment on the machine too, except for the hydraulic system. This was all year long, in the icy winter time, and hot summer time. Even the dump trucks and other machines engines had single grade year round 30 single grade.

 

[Japanese]

And sorry to say but in dirt machines I worked with in the 70's through the early 2000's all we used in the old dozers was single grade 30 series 3 oil, and it was in every compartment on the machine too, except for the hydraulic system.

Are you still comparing construction/commercial equipment with civil cars, motorcycles and generators?

 

[kschachn]

You cannot use single grade oils in temperatures below 32°F in a car engine. So only this thing makes them not usable, not only in modern cars, but in any cars, even those from 50 years ago.
Matter a fact you cannot use single grade oils below 32°F in other civil equipment too (motorcycles, garden equipment, ect.)

Where are you pulling that from? For example, some of the available 30 grades without VII are also capable of being labeled as a 10W-30, so it would be guaranteed for cranking and pumping at least down to 0F.

 

[Japanese]

For example, some of the available 30 grades without VII are also capable of being labeled as a 10W-30, so it would be guaranteed for cranking and pumping at least down to 0F.

Let's see them.
Pretty sure I was looking at HPL SAE30 and there is no rating below 32°F.

 

[Hohn]

In the latest LSJ video, facts about 0W-20 and 5W-30. I just find it funny that there is no mention that shear is mostly a multi grade oil problem.

There is a reason that the most expensive engines past and present, have always specified, single/ non multigrade oils.

He talks about the spread between the lower and higher numbers as the problem (my words). Of course more polymers are added to make the base oil make it to the upper number.

So am I close?

No, pretty far off. There's actually very, very little evidence to support the bald assertion you claim in the second line.

A QSK95 costs nearly a million bucks and uses 15w-40 Premium Blue.

Single grade oils are often just a license to make the oil be the cheapest swill that can meet some pretty relaxed specs. If you survey the world of monogrades, must of them are really poor, min-spec formulations. Think Valvoline Daily Protection or worse.

Exceptions exist of course-- notably the SAE 30 and SAE40 grades of PCMO from HPL.

 

[edyvw]

No, pretty far off. There's actually very, very little evidence to support the bald assertion you claim in the second line.

A QSK95 costs nearly a million bucks and uses 15w-40 Premium Blue.

Single grade oils are often just a license to make the oil be the cheapest swill that can meet some pretty relaxed specs. If you survey the world of monogrades, must of them are really poor, min-spec formulations. Think Valvoline Daily Protection or worse.

Exceptions exist of course-- notably the SAE 30 and SAE40 grades of PCMO from HPL.

OP once seriously asked why today we don’t use piston engines in airliners.
So….

 

[Hohn]

You cannot use single grade oils in temperatures below 32°F in a car engine. So only this thing makes them not usable, not only in modern cars, but in any cars, even those from 50 years ago.
Matter a fact you cannot use single grade oils below 32°F in other civil equipment too (motorcycles, garden equipment, ect.)

Not necessarily, but often true. The HPL monogrades are sort of the exception that proves the rule.


HPL SAE 30: -45C pour point, KV40 of 74.8, D1G2 additives, high moly, GTL, AN, Ester base oils. TBN of 13+.VI is 122.
Valvoline Daily Protection SAE 30: -18C pour point, KV40 of 81, API SQ, Group I/II blend, no GTL, no AN, no Ester, TBN of 6.8. VI is 108.


The only thing these oils have in common is meeting the latest API spec and sharing a viscosity grade.

That makes it entirely in appropriate to make broad assertions purely on viscosity grade and not accounting for actual formulations.