The Peckish Synapse

[Grumpy Bear]

HTHS vs Fuel Economy

 

High Temperature High Shear, a test conducted at 150 C / 302 F. The approximate temperature of the oil in the ring land area for a naturally asperated motor running on gasoline. 40% of such a motors running friction comes from the ring to cylinder interface. So the thinking goes, lower the friction in this place and reap a reward in fuel efficiency. It is stated by supporters as  categorically true. Or at least that is the hope. 

 

G8Oils: ©2021 Kuwait Petroleum Copyright 2020. All rights reserved. https://www.q8oils.com/automotive/low-hths-oils/

 

After you read this white paper THINK. 

 

Note that peak fuel efficiency hits about 2.6 cP but wear improves past 3.5 cP.  Once that sinks in and knowing that the HTHS minimums are for various grades: 

 

 

So if the 0W20 starts at the peak what happens when that number deteriorates as the oil oxidizes? Why does the fuel efficiency degrade with lower HTHS? Because metal to metal contact increases friction despite the EP/AW additive package. 

 

If economy is your thing: 

 

Idemitsu 0W20 at 2.6

https://www.idemitsulubricants.com/product/idemitsu-0w-20

 

Mobil 1 Advance Economy 0W20 Dexos2Gen2 data sheet list this value at 2.7 value.

 http://products.petrochoice.com/system/documents/3729/1/Mobil_1™_0W-20.pdf?1463683931

 

AMSOIL SS 0W20 at 2.7

https://amsoilcontent.com/ams/lit/databulletins/g2880.pdf

 

Red Line HP 0W20 at 2.9

https://www.redlineoil.com/Content/files/tech/0W20_MO_PROD_INFO.pdf

 

MPT 30K 0W20 at 3.2

https://www.redlineoil.com/Content/files/tech/0W20_MO_PROD_INFO.pdf

 

If longevity is your thing: 

 

Idemitsu 5W30 2.97

AMSOIL SS 5W30 3.11

Mobil 1 5W30 3.24

Red Line HP 5W30 3.7

MPT 30K 5W30 3.9

 

 

 

 

 

 

 

 

 

 

 

[MikeBMW]

So, we wait for the peckish replies?

[Donstar]

12 hours ago, MikeBMW said:

So, we wait for the peckish replies?

Most of Grumpy's comments of this thread are informational and thought provoking.  They are a good read and don't often require replies.  I typically need to be on my third cup of coffee before tackling this topic.  It is like the good old days of newspapers when  I'd turn to the comics and Ann Landers before hitting the good stuff!    

[Grumpy Bear]

Chew On This Awhile

 

If you ever want to know how 'true' synthetics differ from mineral based synthetics you have to understand where they come from. 

 

 

[Grumpy Bear]

www.infineuminsight.com

 

With a growing number of OEMs pushing customer subscriptions, we may see more dealer-based car servicing. This means that vehicles that could use SAE 0W-16 are more likely to be service filled with that grade during a dealer based service.

 

For maintenance outside of dealer control, consumers could use 3^rd party service providers or carry out oil changes themselves. And, in these cases, despite the fact that good quality oil protects the engine there may be a tendency to select more conventional or higher viscosity oils rather than SAE 0W-XX and premium performance products if they are given the option and allowed.

 

Oh boy. 

[Grumpy Bear]

Is the light bulb getting any brighter? 

 

 

 

https://jyx.jyu.fi/bitstream/handle/123456789/57491/1/URN%3ANBN%3Afi%3Ajyu-201804051926.pdf

 

 

Edited April 21, 2021 by Grumpy Bear

[Grumpy Bear]

18 hours ago, Grumpy Bear said:

 

 

There are 65,000 known oil fields in the world. 94% of the world current reserves come from but 1,500 of them. Everyone of these has it own 'signature'. That is every fields oil has a unique blend of hydrocarbons. C1 methane to C70H142 Heptacontane. These are rough cut via distillation into product 'groups' and the lubricating group is C20 - C50. THOUSANDS of spieces of hydrocarbons. This cut is dewaxed and hydrocracked and hydrogenated to a smaller and more saturated base oils. How much processing depending on the need for then end product. Group II is treated less than the Group III. The end product for a Group III 5W30 may look something like: 

 

 

A chromatogram in bar chart from to show more detail in makeup.

 

Before processing the red parts of the bar were a greater portion of each chains length. Straight chain alkanes reformed and saturated into cyclic-alkanes and other straight chain alkanes into isoparaffins (branched alkanes). A small amount of normal alkanes remain. Saturated is more stable than unsaturated and isoparaffin more stable than cyclic structure (Oxidation resistance)  Chain length is limited to prevent waxing which improves pour point. 

 

Okay here's where this is going....That chromatogram will be different in composition from every oil field and from every blend of fields. It will even vary from the same field over time thus so will it's performance. 

 

 

[Grumpy Bear]

https://www.mdpi.com/2075-4442/6/3/73/htm

 

Some light reading  

 

This study compares a PAO/Ester to a Group III/Ester to a PAO/Group III

 

Another on base stock compositions including GTL

 

https://www.routledge.com/rsc/downloads/Ch2.10.1201_b19217-9_(1).pdf

 

 

 

Edited April 22, 2021 by Grumpy Bear

[Grumpy Bear]

 

From the link above:

 

 

Group III+ is GTL and the cleanest of the Group III base oils and yet it still contains:

 

 

PAO's on the other hand are linked together. Like this: 

 

 

 

The honeycomb structure gives higher oxidation resistance.

 

[Grumpy Bear]

Degradation=

 

Additive depletion > Oxidation > Polymerization

 

That's the order and that order is not discrete. No sharp lines. No absolutes. 

 

 

This has been happening in motors with under 80K miles on them who have their oil changed by the OLM and using dealer supplied Dexos1Gen2 oil. Forget what you see between the rings. Look at the piston just to the right of the pin. That orangish brown build up of varnish/lacquer...that is polymerization. There wasn't any UAO that would have said the oil was out of oxidation additives and the base was under attack. Not taken from the bulk oil. Depletion, oxidation, polymerization need only two things. Heat and time. How much time depends on how much heat.

 

Locally

 

The oil in a bottle on the shelf of the auto parts store is far enough removed from the motors sump to not be affected by what it going on in the pan. As ignorant as that sounds the same is true IN the motor. The oil in the pan is not suffering the same conditions the oil under the head of the piston are. It is only the act of circulation and dilution that make it appear so. 

 

 

This is a piston I took out of a Royal Enfield with under 5K miles on the motor and the oil changed every 1,000 miles. Mobil 1 20W50. Polymerization is already at work. What happed between the ring of the upper piston photo are what happens when polymerization gets to the point the dispersant package can no longer hold it in suspension and the detergent package can not prevent it from adhering. I'll bet the UOA would not have shown that it was 'all used up'. 

 

A Group II conventional oil has the ability to prevent wear when it is fresh. The difference in base oil the is it's natural ability to resist oxidation AFTER the additive package is no longer functional. The more paraffinic that base the longer it will take the same temperature before polymerizing. And if you have an application that even a PAO will not handle then look to Polyol Esters.

 

I know boutique blenders like to trot out the extended OCI as a big plus of the PAO/POE oils but it is really the fact that given the same OCI's they leave far less deposits. Not because of better additives but because of better bases. 

 

The antioxidant chemicals used in motor oils do have a temperature they are no longer effective. Is is very hot but it is also possible within specific locations in the motor. The Gen V motors use a spray of oil under the piston crowns not to lubricate but to cool things down to a temperature UNDER the polymerization temperatures created locally under hard loads.

 

  

[Grumpy Bear]

Between the Rings

 

 

https://dieselnet.com/tech/combustion_piston-cool.php

 

Quote from the link above: 

 

Also, coking of the lubricant can lead to carbon deposits in the ring groove that can act as an insulator or cause ring sticking.

 

So how hot does it have to be to do this? 

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7178296/

 

Go to section 4.1 and review the graphs. Answer 250 C. 

 

And how hot did Mahle measure temperature between the two top rings?

(Use the Diesel drawing as the text includes N/A GDI motors in that group)

 

Well over 250 C! 

 

Some context here. That study does not mean that the oil space between the top two rings runs over 250 C constantly . It means that is the temperature at WOT and peak LOAD. Something that happens allot when a 2.4 N/A motor is pushing a boxcar down the interstate into a head wind or your grinding out the Eisenhower grade pass at WOT in 4th gear matted. Your Turbo GDI 1.5 pushing that 5,000 SUV lives there allot. 

 

For the Imperial crowd 250 C is 482 F. 

 

Don't believe it gets that hot?

Look at the photo again.

 

At roughly 500 F the antioxidants fail.

 

Remember that for every 18F (10C) the rate of degradation DOUBLES past that oils INITIATION temperature which is well below 500 F. As low at 180 F for Group 1 bases (not normally used) to just under 300 F for PAO's. Less for Group III and Group III+. That sharp bend in the acid curve where the antioxidant fails is something like a fireman standing in a burning building and removing his protective coat and exposing his flesh to contact with the flames. 

 

Mobil 1 claims protection to 500 F. The break point of the antioxidant. But does so without point of reference. TIME. Even at the lower 'normal' temperatures of relaxed cruising those additives are being consumed and that rate of consumption increases with exposure to more heat. 

 

When someone claims that 'todays' Group III oils will perform on par with a PAO/POE they do so on the basis of the additive package not on the basis of the base oil. They do so without reference to TIME.

 

https://www.researchgate.net/publication/227761781_A_Mechanism_of_Thermooxidative_Degradation_of_Polyol_Ester_Lubricants

 

MOST PAO's contain minimum of 10% POE's. Some as high as 35%. POE's will take 250 C without an antioxidant and yet still contain them. The PAO on it's own will hold and reject 15% more heat than a Group III+. The Ester addition does not diminish that. The Ester lowers friction significantly when the blend is at least 15% (peak) and cut even at 10%. So these PAO/POE blends run cooler two ways. In my junk a 10-15F reduction in bulk temperatures is common. 

 

The OEM's have taken back more than "today's oils" have delivered. 

 

Lowering viscosity

Lowering HTHS viscosity

Lower additive levels

Increasing water temperatures

Increasing unit power densities

(GDI and Turbo)

Larger heavier vehicles

Larger frontal areas

Heavier payloads and tow capacities

Limited to no oil cooling

Transmission thermostats

Slipping lockup converters

Stupid high 'limp mode' trigger points

Fan delay to past 210 F.

Engine bay sealing.

 

OWNERS take more:

Ignoring speed limits

Ignoring tow and payload

Drinking the 'today oils' Kool-Aid

Drinking the Extended OCI Kool-Aid

Ignoring break in procedures

Beat it like a pup

Use the lowest grades of oil and filtration

 

And what do you get doing all that?

 

My truck uses oil?

 

 

 

 

[Grumpy Bear]

2004. This older guy comes rolling into Casey's to air up a tire. Not a picture of his truck but a picture of one like his truck. I didn't have my phone handy. (I was hogging the air  ) 

 

Rust free but not quite this clean. It's planting season here, so his was covered in a film of field dust.  I was this color and trim and conversing with him I find it has a 5.3 for power and a 4 speed automatic.  250,000 absolutely trouble free miles. Uses no oil. Doesn't leak. Except for the leaky tire . No dents, no rust, just really well maintained. Unusual for a Rust Belt Farm truck.

 

I asked him if he was considering buying a new one as this one had 'allot' of miles on it. (hoping he'd say yes so I could make an offer). 

 

He laughed at me. "You're a funny guy, this one isn't even broke in. Besides they don't make this truck anymore". 

 

"GMT800"? I puzzle.

 

"No, a reliable RCSB", he winks "Or any RCSB for that matter", he trails. 

 

 

She is pretty.

[Grumpy Bear]

Down the Rabbit Hole

 

It's a shift of focus. Taking you eye off what "They" want you to hear to what was actually said. I kid you not. What! You need an example? Okay. 

 

So you need to focus on the idea that HTHS viscosity is the Holy Grail BECAUSE???? Ring drag represents 40% of a motors total friction and HTHS is the temperature rings run at bimbo! 

 

Wait.....40%? Only 40%? So the majority...60%..is irrelevant? Then there is the minor detail that the oil temperatures between the top and second ring only reach HTHS temperatures at???????......Max torque WOT. Hummmmmm. Yet..it works every time.... WOW! 

 

I'll try another one later. It's late....

[Grumpy Bear]

Around 20 minutes in note the OCI and volume of this motor. And people thing I run short OCI's. 

 

Enjoy. One of the best car videos ever IMHO. 

 

 

[Grumpy Bear]

I go on a diet and the dog looses weight.

Good dog!

 

I would not have stuck with this if it were not for the App Mrs. Bear put on my phone. This app you load in what you eat and how much of it. It breaks it down nutritionally as well a calorie count. And I mean it breaks it down. Not just how much fat, but what kind. Mono? Poly? Sat? Trans? Omega 3? Ditto carbs. Tracks some of the more often neglected vitamins and minerals. Sodium and iron. Watches my alcohol intake and sugars as part of the carb count. Adjust for your exercise too! 

 

As amazing as all that seems to be what is more amazing is how easy it is to eat poorly. And you never know your doing it unless your tracking it. Even when you think you are making good choices you are more often than not just making choices that are less bad.  It's really easy to box yourself into a corner. For instance a few bad choices at breakfast can leave you without room for health fats from veggies later. You can run yourself out of calories (required if loss is really the goal) by mid day. Even by breakfast. Yea...2,000 at breakfast is really easy...

 

On the up side you can eat a silly amount of food...more than you care to eat, with some more considered choices. 

 

There's that joke that goes, "If it taste good, spit it out". Well....not true. What is true is that if  you are mindless about what you stick in you mouth then it becomes true. 

 

Hitting my calorie goal is actually easy. Hitting my nutrition goals is allot harder and requires some thought and study. It actually becomes sort of addictive in the same way video games can be. Yes..it becomes a game where the 'prize' is you health. You learn that being satiated is not the same thing as being full. Being full can be very unsatisfying. 

 

You learn to leave room for your 'night cap' and that deserts are not served after every meal nor even every day. That was a hard one; learning that cookies, pie and ice cream are not one of the food groups.

 

Oh yea, I'm loosing weight too.  The same way I put it on...slowly