LSJr video about vis, wear, viscosity, etc

[ZeeOSix]

At time 8:41 he skirts around one of the most important oil performance specs ... the HTHS viscosity. A higher HTHS viscosity will give more MOFT and more engine protection than a lower HTHS. The HTHS test is meant to show how the oil will behave at higher temp and shear rates, like seen inside journal bearings. And of course, the other factor of how "shear stable" (ie, how much permanent shear happens) the oil is over the OCI matters. As brought up earlier fuel dilution can have a huge impact on KV100 and HTHS in operation ... the basic effect is like permanently shearing the oil.

 

[ZeeOSix]

He says the most shear stable oil results in the less wear ... which is another way of saying higher viscosity results in less wear, because if the oil shears down and become less viscous it causes more wear.

 

[LZ0 Bob]

I watch LSR vidoes like my daughter watches "Love Island". Something to do, while your munching on some popcorn.
The same can be said about this website.

Folks get all super caught up in the semantics of oil chemistry..... like if you get even a tiny bit of it wrong...... your engine is doomed.

Look at the 100's of millions of cars on the road.... every day. 99% of them have owners that are clueless about oil and filter selection. Yet, here they all are, racking up mile after mile on some of the cheapest oil and filters available. Most of them are probably at least 1 qt low too.

Yet the Speed Diagnositix folks are worried to death that their total wear metal count is 11 ppm and they want it under 10.

The roads would be littered with cars with blown up engines, if any of it made a bit of difference. But it doesnt.

It's like arguing which beer is better. It all gets you drunk.

 

[ZeeOSix]

The roads would be littered with cars with blown up engines, if any of it made a bit of difference. But it doesnt.

Dead cars on the side of the road would be a bad metric to determine how many are more worn out than they should be, for whatever reason. Go watch the YouTuber "I Do Cars" and see how many messed up engines he tears down all the time.

 

[buster]

I just watched it fully through and thought it was very good. Touched on a lot of things that are often discussed here.

Interesting comment about the moly/wear correlation.

Most engines can run on multiple viscosity oils with no noticeable wear differences. This is also suggested by many owner's manuals that show multiple grades can be used.

Viscosity is obviously super important, but so are other things.

 

[JavierH19]

Oh yeah i forgot about that light purple laundry softener jug looking motor milk trash.

 

[ZeeOSix]

Interesting comment about the moly/wear correlation.

Moly is an effective AF/AW additive, which helps mitigate wear when parts start rubbing together when the tribofilm has to kick in after viscosity can't do the job anymore (ie MOFT goes to zero).

 

[johnmyster]

The point was if you had say a 5W-30 in the sump instead of a 5W-20, then you wouldn't have to think as much about all the different use conditions you might run into while using the vehicle.

I've always read that the specified grade was only applicable for a 70F day at sea level, no towing, easy cruising on flat/level ground with the A/C off, two 150 pound passengers with 200 pounds of luggage/gear, stock size tire, within warranty period, on the way to church. Outside of any of those parameters on the specified grade would be uncharted territory.

Anything beyond this, it's up to me to figure out how many grades to go up. I'm glad 20w-50 and 10w-60 exist.

 

[ZeeOSix]

I've always read that the specified grade was only applicable for a 70F day at sea level, no towing, easy cruising on flat/level ground with the A/C off, two 150 pound passengers with 200 pounds of luggage/gear, stock size tire, within warranty period, on the way to church. Outside of any of those parameters on the specified grade would be uncharted territory.

Anything beyond this, it's up to me to figure out how many grades to go up. I'm glad 20w-50 and 10w-60 exist.

Obvious sarcasm aside, pretty much every high performance car maker says to use thicker oil for track use. Toyota OMs basically say that thicker oil will add engine protection if the vehicle is used for more severe conditions - not a huge surprise. If it wasn't something that helps protect an engine under more stressed use conditions they wouldn't make that recommendation.

 

[kschachn]

I watch LSR vidoes like my daughter watches "Love Island". Something to do, while your munching on some popcorn.
The same can be said about this website.

Folks get all super caught up in the semantics of oil chemistry..... like if you get even a tiny bit of it wrong...... your engine is doomed.

Look at the 100's of millions of cars on the road.... every day. 99% of them have owners that are clueless about oil and filter selection. Yet, here they all are, racking up mile after mile on some of the cheapest oil and filters available. Most of them are probably at least 1 qt low too.

Yet the Speed Diagnositix folks are worried to death that their total wear metal count is 11 ppm and they want it under 10.

The roads would be littered with cars with blown up engines, if any of it made a bit of difference. But it doesnt.

It's like arguing which beer is better. It all gets you drunk.

View attachment 347689

If you say so. I’d rather have solid technical information but maybe that’s just me.

Semantics and all.

 

[johnmyster]

Yes, I’m still a bit fuzzy on the compelling technical reason not to go up a grade or two.

Like I’ve said before, if your one and only goal is to obtain a small reduction in fuel consumption, then go for it. After that, why again am I doggedly sticking to thinner oils?

It's not that it isn't worth considering going up a grade or two. But it isn't worth going up two grades, then gathering up all the competing UOAs to split hairs and argue over some additional fraction of measured viscosity gain at the end of the interval.

Ironically, that was kinda LSJr's point: once you have sufficient (and perhaps a little extra) viscosity, chemistry is more important than gaining more.

But maybe I'm just oblivious because exactly zero of the three engines sitting in my driveway are known for lubricant related, hard part wear failures. Or fuel dilution. Or shearing down oil. I can't think of a single car in my life where I was paranoid of such. But if I had a 6.4 hemi or 6.2 gm (for example) and was searching for band-aids for poor mechanical design I might have other life goals. It's just not high on my lost-sleep 8D causal factors list.

I did snap a rod on a snapper riding mower that one time though after it sized the rod bearing. Maybe I should re-evaluate my position.

 

[ZeeOSix]

The standard around here is if the engine still runs "good" and doesn't blow-up, then everything they use in/on it (oil, oil filter, air filter) must be fantastic and no extra wear is taking place because oil is oil and filters are filters, lol.

 

[johnmyster]

Obvious sarcasm aside, pretty much every high performance car maker says to use thicker oil for track use. Toyota OMs basically say that thicker oil will add engine protection if the vehicle is used for more severe conditions - not a huge surprise. If it wasn't something that helps protect an engine under more stressed use conditions they wouldn't make that recommendation.

My Toyota doesn't see track use.

It gets four cold starts a day and drives one mile to drop the girls at daycare because my suggestion on using the stroller or bicycle didn't get very far. Once a week it goes 2.5 miles to the grocery and 3.5 miles to church. Highest speed limit it sees is 35 mph. Sometimes it sees a "longer" trip to do something else.

Your logic is I should split hairs over thicker oil anyway because there must be some inherent benefit? Mobil1 FS 0w-40 is only a small step in the right direction?

My selection criteria is mostly 1) rebate gets me two jugs a year, which does two OCIs in that vehicle and 2) given the amount of short trips, an A3/B4 seems like a step in the right direction for port-injected motor that I'm trying to keep clean, including VVT actuators.

 

[OVERKILL]

But if I had a 6.4 hemi or 6.2 gm (for example) and was searching for band-aids for poor mechanical design I might have other life goals.

Just to nit-pick a bit here, but the 6.4L HEMI doesn't suffer from any mechanical design issues. It has a lower rate of occurrence of the common lifter failure issue that affects its sibling, the 5.7L HEMI, as well as basically every GM pushrod engine and Ford's 7.3L Godzilla. Updated lifters from Germany were introduced in ~2018 that were supposed to remedy the issue, and my understanding is that they greatly reduced the occurrence. The AFM/DFM GM engines also experience a failure of the deactivation mechanism, not just the roller failing, something not observed with MDS.

 

[ZeeOSix]

My Toyota doesn't see track use.

It gets four cold starts a day and drives one mile to drop the girls at daycare. Once a week it goes 2.5 miles to the grocery and 3.5 miles to church on Sunday. Highest speed limit it sees is 35 mph. Sometimes it sees a "longer" trip to do something else.

You should probably go down a grade or two, lol.

Your logic is I should split hairs over thicker oil anyway because there must be some inherent benefit? Mobil1 FS 0w-40 is only a small step in the right direction?

The logic (which you don't grasp) is to have some added MOFT headroom. Why possibly operate on the ragged edge when you don't have to by going up a grade from a xW-20 or lower. xW-20 is pretty much on the edge of effective HTHS in more than benign use conditions. I would run xW-40 if tracking a car.

Why do you think Ford changed the viscosity from 5W-20 to 5W-30 on the V8 Coyote, and gave up CAFE credits.

 

[johnmyster]

Just to nit-pick a bit here, but the 6.4L HEMI doesn't suffer from any mechanical design issues. It has a lower rate of occurrence of the common lifter failure issue that affects its sibling, the 5.7L HEMI, as well as basically every GM pushrod engine and Ford's 7.3L Godzilla. Updated lifters from Germany were introduced in ~2018 that were supposed to remedy the issue, and my understanding is that they greatly reduced the occurrence. The AFM/DFM GM engines also experience a failure of the deactivation mechanism, not just the roller failing, something not observed with MDS.

I'm an older truck consumer and the 6.4s I auditioned all seemed to be chatterboxes. I'm not saying those two are the only engines out there that exhibit mechanical wear with mileage. We could cite modern kia/hundai examples too, I suspect.

 

[OVERKILL]

I'm an older truck consumer and the 6.4s I auditioned all seemed to be chatterboxes. I'm not saying those two are the only engines out there that exhibit mechanical wear with mileage. We could cite modern kia/hundai examples too, I suspect.

The HEMI's are not quiet engines, I've owned 4x 6.4L's. If you are familiar with their valvetrain design, it makes sense. Doesn't help that the trucks are also prone to exhaust manifold leaks. This isn't a wear-related issue, it's just how they are.

You've made me feel old, lol. The 6.4L in the truck was introduced in 2014, when I think "old trucks" I'm thinking like 7.3L PSD Super Duties as being on the "newer" end of that spectrum

 

[johnmyster]

You should probably go down a grade or two, lol.

What footnote in the manual tells us that thinner oil is better for the grandma duty cycle, and how is 0w not satisfying said requirement?

The logic (which you don't grasp) is to have some added MOFT headroom. Why operate on the ragged edge when you don't have to by going up a grade from xW-20. I would run xW-40 if tracking a car.

Because for most cars on the street, they're being fed whatever grade is on the cap by jiffy tech and we don't really hear of failure rates that indicate ragged edge operation. So it appears 1) headroom does exist and 2) I do grasp the logic, and yet my purchasing choices are indicated in my signature.

A 2GR-FE fed 0w-20 per backspec (my cap says 5w-30) will still run when roaches roam the earth, despite whatever front cover leaks it may have.

The nuance (which you don't grasp) is that "grabbing headroom" implies that there is none to begin with, which for most users is an overblown non-reality.

If you want to use 40wt on the track for a car with runaway oil temperature and/or sloshes the sump in corners, then those are two different reasons. As LSJr acknowledges, at high rpm the stribeck curve is on your side and the need to chase viscosity is actually less.

I'll list my stash on marketplace tonight and start to stock up on 15w-50. I love this place.

 

[cheesepuffs2]

That was sarcasm. The point was if you had say a 5W-30 in the sump instead of a 5W-20, then you wouldn't have to think as much about all the different use conditions you might run into while using the vehicle.


Not every vehicle on the road has an automatic transmission, and not everyone has the same driving skills.

It's amazing how much push back there is about going up a grade.

I’m not even pushing back. You’re talking to somebody who went up a grade in both of their cars. But there’s nuance to it, and that’s my whole point.

 

[johnmyster]

The HEMI's are not quiet engines, I've owned 4x 6.4L's. If you are familiar with their valvetrain design, it makes sense. Doesn't help that the trucks are also prone to exhaust manifold leaks. This isn't a wear-related issue, it's just how they are.

You've made me feel old, lol. The 6.4L in the truck was introduced in 2014, when I think "old trucks" I'm thinking like 7.3L PSD Super Duties as being on the "newer" end of that spectrum

Old is relative. The 6.4 is old at 150k miles. A 7.3 isn't old at 2x or 3x that.

Sorry if I picked on your favorite engine.