HTFSV: High-temperature, full-shear viscosity

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Ok im puzzled once again. What are we doing here? Everything always ends the same way. "Stand in the oil isle, blindfold self, grab for oil, use selected oil" because in all doubt it doesnt matter. Oh, as long as its the cheap one with a rebate! Uoa/noa thread is a ruse? The concept of how an oil is holding up to your engine is deterrent basically. I just want the better oil, and apparently it just doesnt exist. $90 for a full syn oil change at the ford dealer. Over 60 for syn blend. I can buy full syn oil and mc filters off the shelf at walmart for half that or less with rebaits and still have enough money to do an uoa if i choose. The reason im here is (What oil on the shelf at wm is better) if you can point me in that direction. Thanks. But there isnt an answer, never was, never will be apparently, so I figure that doing it my way "wrong or not" I will feel better about what I paid for.
 

MolaKule

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People who work as lubrication analysts or as consultants in factories have a good idea of the metallurgy contained within their machines and look for long term trending using expensive analyses. 1) Average Joe does not have any idea of the metallurgy contained within their engines or gear boxes, 2) Most UOA's that are seen here are short-term snapshots, not long term trending, 3) Without VOA's of every oil you put into an engine, UOA's are worthless because formulations change often, 4) UOA's might help you spot a coolant leak, but without a current VOA to spot changes in additive levels, you will not know if a partucular additive chemistry has changed or if you have some coolant intrusion, 5) And for sure, no spreadsheet with dubious assumptions will help you in choosing an oil. Mola's ROT (Rule of Thumb)[No, not Mola's rotting thumb smile ]: If you decide to do oil changes at Severe Service intervals, use a new filter and a conventional oil of the viscosity grade specified for your vehicle. If you decide to do oil changes at non-Severe Service intervals, use a new filter and a Blend or synthetic oil of the viscosity grade specified for your vehicle. If you live in extreme temperature climates use a new filter and a full synthetic oil of the viscosity grade specified for your vehicle. If you track or race on the weekends install a Boutique full synthetic Racing oil of the viscosity grade specified for your vehicle and drain it immediately afterwords replacing it with your Daily Driver Oil (DDO) and a new filter.
 
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11,826
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PA
Originally Posted by GaryPoe
Ok im puzzled once again. What are we doing here?
Great question.
Originally Posted by GaryPoe
Everything always ends the same way. "Stand in the oil isle, blindfold self, grab for oil, use selected oil" because in all doubt it doesnt matter. Oh, as long as its the cheap one with a rebate!
No, that's the opposite extreme. There's still a lot of variety on the shelf, and it matters that you pick an oil that meets the specs your engine calls for. If you have five oils in front of you and all of them meet the specs you need, then yeah, it's highly unlikely that you'll be able to tell a difference among them, and even if you could, the differences would probably be so minor that you'd never know it. That's the point at which it doesn't really matter which one you pick. But that doesn't mean you can throw any old oil in your engine and expect success. It still has to be the right spec.
Originally Posted by GaryPoe
Uoa/noa thread is a ruse?
It's not a ruse. It has value. Just not the value that most people put on it.
Originally Posted by GaryPoe
I just want the better oil, and apparently it just doesnt exist.
Well technically, it exists; we'll just never know what it is. lol But seriously, the flip side of this is that you can use anything that meets the specs laid out in your owner's manual, and feel good that you're probably doing just about the best you can. You might be shocked to see how many people -- and even "reputable" shops -- can't even manage that.
 
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Council Bluffs
Yes i suppose your right. Im just particularly picky. Ill never trust dealer oil changes for several reasons. I figure if your going to do something, its worth doing it right. cylon
 
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Regina, Saskatchewan, Canada
Originally Posted by MolaKule
1) Average Joe does not have any idea of the metallurgy contained within their engines or gear boxes, 2) Most UOA's that are seen here are short-term snapshots, not long term trending, 3) Without VOA's of every oil you put into an engine, UOA's are worthless because formulations change often, 4) UOA's might help you spot a coolant leak, but without a current VOA to spot changes in additive levels, you will not know if a partucular additive chemistry has changed or if you have some coolant intrusion, 5) And for sure, no spreadsheet with dubious assumptions will help you in choosing an oil.
This should be a sticky in the analysis section.
 
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New England
Originally Posted by GaryPoe
Yes i suppose your right. Im just particularly picky. Ill never trust dealer oil changes for several reasons. I figure if your going to do something, its worth doing it right. cylon
My Subaru dealer kept giving me invoices that said they had put 0W20 in my FXT when the manual recommended 5W30 (and synth)...I would point this out every time and get a totally blank look for a few seconds. Then the "service advisor" would study my invoice with a very serious look on his face and say something like "that's just what the computer does" and that they MUST have used the right oil! I think the problem was that the turbo Foresters were quite rare (and have been dropped for now) and 0W20 was recommended for the 99% with the 2.5l NA engine. It's certainly possible that 5W30 was actually used (it's printed right on the cap!), but I had no confidence that that was definitely the case. After this happened 2-3 times and that dealer also mangled my drain plug, causing a huge mess in my garage, I finally started changing my own oil. I am really glad I made the change! (pun intended)
 
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Wet side WA
Originally Posted by Virtus_Probi
Originally Posted by GaryPoe
Yes i suppose your right. Im just particularly picky. Ill never trust dealer oil changes for several reasons. I figure if your going to do something, its worth doing it right. cylon
My Subaru dealer kept giving me invoices that said they had put 0W20 in my FXT when the manual recommended 5W30 (and synth)...I would point this out every time and get a totally blank look for a few seconds. Then the "service advisor" would study my invoice with a very serious look on his face and say something like "that's just what the computer does" and that they MUST have used the right oil! I think the problem was that the turbo Foresters were quite rare (and have been dropped for now) and 0W20 was recommended for the 99% with the 2.5l NA engine. It's certainly possible that 5W30 was actually used (it's printed right on the cap!), but I had no confidence that that was definitely the case. After this happened 2-3 times and that dealer also mangled my drain plug, causing a huge mess in my garage, I finally started changing my own oil. I am really glad I made the change! (pun intended)
You may have just run across the reason many Subaru turbo users are having trouble with they cars. Once again if you want it done right and have some peace of mind do it yourself.
 
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190
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Council Bluffs
Ive been staring at this for days now and have a ? How does VAS 5w20 get a vii of 0.23% and M1 EP 5w20 get 4.17%? VAS has a hthsv of 2.7 while m1ep is 2.75, m1ep is a thicker oil, is that only due to vii and not the base oil which is why its on the lower part of the list? How did the A-Harman test show that VAS outperformed M1EP, and did the additives in any of these play any roll on the outcome of the tests?
 
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Originally Posted by GaryPoe
Ive been staring at this for days now and have a ? How does VAS 5w20 get a vii of 0.23% and M1 EP 5w20 get 4.17%? VAS has a hthsv of 2.7 while m1ep is 2.75, m1ep is a thicker oil, is that only due to vii and not the base oil which is why its on the lower part of the list? How did the A-Harman test show that VAS outperformed M1EP, and did the additives in any of these play any roll on the outcome of the tests?
Even guessing at the answers to those questions would require intimate knowledge of the formulations (which no one here has) and/or experimental validation of the model Gokhan has laid out here (which no one has attempted and in which he seems completely uninterested). Probably safe to say we'll never know.
 
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Thread starter
Originally Posted by GaryPoe
Ive been staring at this for days now and have a ? How does VAS 5w20 get a vii of 0.23% and M1 EP 5w20 get 4.17%? VAS has a hthsv of 2.7 while m1ep is 2.75, m1ep is a thicker oil, is that only due to vii and not the base oil which is why its on the lower part of the list? How did the A-Harman test show that VAS outperformed M1EP, and did the additives in any of these play any roll on the outcome of the tests?
The HTHSV definitely increases with the VII content. The amount of the [olefin copolymer (OCP)] VII multiples the KV with the same constant at all temperatures, including at 150 C -- the constant being [1 + 13.7*(VII content)] to be exact. So, for each percentage of the (OCP) VII content, you get a 13.7% viscosity boost. Now, during the HTHSV measurement, part of this viscosity boost goes away due to temporary shear -- 1/6.85 = 14.6% of the viscosity boost to be exact. The viscosity index VI for M1 EP 5W-20 is a lot larger, indicating a lot more VII. Note that the boost in the viscosity index VI depends on the base-oil viscosity, with thinner oils getting a larger viscosity-index VI boost. This is because the KV40 and KV100 are multiplied by the same constant for a given OCP VII content. You can verify this using the Widman viscosity-index VI calculator. Therefore, you can't use the viscosity index VI alone to directly deduce the VII content.
 
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Originally Posted by GaryPoe
Thanks again Gokhan. I had to read it lik 20 times but I follow banana
You're welcome! Note that the actual formula is: HTHSV = {base-oil dynamic viscosity} * {1 + [(VII viscosity-boost factor) * (VII content)]} * {1 - [(VII temporary-shear factor) * (VII content)]} VII viscosity-boost factor = 13.7 VII temporary-shear factor = 2.0 The numbers are for OCP VII, which is by far the most common VII type, as it is far better in passing the engine- and turbocharger-deposits tests. So, the fraction of the temporarily sheared viscosity will be a little different than 2.0/13.7 = 14.6% of the viscosity boost, which is what I said before. This formula gives you the exact numbers in my table. Note that I called the base-oil dynamic viscosity at 150 C with the name "high-temperature, full-shear viscosity" (HTFSV). In reality, there is probably never a full-shear regime, as a second Newtonian phase is entered at some point when the shear rate gets higher, but the name means that I am referring to the base-oil viscosity without having been influenced by the presence of the VII. Many studies show that the base-oil viscosity plays a role in wear in the boundary- and mixed-lubrication regimes, such as the valvetrain, timing chain, and piston rings/cylinder liners. It is not simple and clear how the base oil, VII, and AW/EP/FM additives interact in these regimes. In any case, the base-oil viscosity is another viscosity of importance in predicting wear, alongside HTHSV. In addition, many people prefer a smaller VII content to help reduce the engine deposits and the table lists this as well.
 
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OH
Well, you can focus on the information that's available and use it to read the tea leaves and determine which oils have a greater percentage of higher quality basestocks in their basestock blends. Generally, an oil offering both good NOACK and good CCV/MRV numbers will have a more costly blend of basestocks than one that's merely mediocre. You can also look for the proportion used of the most costly add, moly. If you want to focus on one figure of merit you could do a lot worse than looking for lower NOACK within the grade you intend to use. We are not completely blind in considering oil quality as judged by what can be gleaned from published data. I'd worry more about deposits than wear personally. When was the last time you saw any engine that was actually worn out using anything resembling motor oil?
 
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Council Bluffs
I had a chevy blazer with a 4 banger in it a long time ago that was absolutely worn out. It didnt burn oil, no macanical issues whatsoever and it ran very well, but it was incapable of performing well because it was just worn out. I remember having to nearly floor it to keep it at 55mph on the highway, and it had little over 100k on it. My most recent 2011 f350 work truck with the big 6.2 v8, same story, motor never had a single issue, oil changed at the ford dealer every 5k, still ran like a top when we traded off. But it was absolutely worn out at 225k miles. I had a 93 Cadillac sedan deville about 15 years ago, it had 325ish thousand miles on it, ran great and by no means was it worn out. I bought it from my uncle who is also a race car driver and only uses mobil1. I drove it until the transmission literally blew up. Would the car have gotten to 325k miles using some other oil? We will never know, but I would speculate m1 probobly has helped it get there. Deposit cleaning is just as important in my book and goes hand and hand with wear protection, but I cant tell you of any engine that wouldnt run because it was dirty.
 
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Some engines wear badly without regard to oil used while some like the 2.2 pushrod four in your Blazer had no power to begin with. Some engines are simply bad designs from the start. Deposits are a problem in that high NOACK oils can lead to accumulations of carbon around the rings, leading to stuck rings and then very high oil consumption. This is a serious issue. If your F350 "ran like a top" after 225K, how did you determine that it was "worn out"? No oil will overcome the inbuilt engineering compromises that lead to excessive wear that are inherent to any given engine.
 
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Let me clarify... The f350 didnt use any oil, gas milage was always consistant at 8.2mpg, it had valve raddle going uphill on the interstate. It always shifted down to 4th and sometimes 3rd to get to the 4k rpm power band to get it up and over. I started noticing when it would downshift to 3rd to get up and over it took longer and sometimes would turn cruze control off because it wouldnt get up the speed fast enough. Overtaking other vehicles i started having to floor it before lane changes to pass because it didnt have the power to get up to normal driving speeds fast enough which made it dang sketchy changing lanes in front of another car that was driving at normal speeds. Driving this truck for 7 years 365 days a year and 225k miles under my butt sitting in it, i know for fact and without a doubt it was worn out. But it always started, and sounded good and it still ran with no issues.
 
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Originally Posted by fdcg27
... No oil will overcome the inbuilt engineering compromises that lead to excessive wear that are inherent to any given engine.
Also, no oil, no matter how much you obsess about its specifications, will overcome the effects of inadequate air filtration. Allowing an engine to inhale dust is a sure-fire way to wear it out.
 
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190
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Council Bluffs
Agreed. I check the air filter usually when i check oil. It doesnt get that bad in the summer, but in the winter when the salt is flying, the fine salt dust is like a low hovering cloud on the interstates. The work truck gets one every other oil change needed or not i dont pay for it.
 
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Originally Posted by Gokhan
Note that the actual formula is: HTHSV = {base-oil dynamic viscosity} * {1 + [(VII viscosity-boost factor) * (VII content)]} * {1 - [(VII temporary-shear factor) * (VII content)]} VII viscosity-boost factor = 13.7 VII temporary-shear factor = 2.0 The numbers are for OCP VII, which is by far the most common VII type, as it is far better in passing the engine- and turbocharger-deposits tests. This formula gives you the exact numbers in my table.
It just occurred to me that I could also calculate the base-oil viscosity index (base-oil VI), which tells us about the base-oil quality, as the higher the base-oil viscosity index, the higher the base-oil quality is! Calculating the base-oil viscosity index is very simple. First, calculate the base-oil KV40 and base-oil KV100 using the VII content from the table as follows: {base-oil KV40} = {KV40} / {1 + [(VII viscosity-boost factor) * (VII content)]} {base-oil KV100} = {KV100} / {1 + [(VII viscosity-boost factor) * (VII content)]} VII viscosity-boost factor = 13.7 (Enter the VII content as a fraction: 1% = 0.01.) Then, plug in the base-oil KV40 and base-oil KV100 into the Widman viscosity-index calculator and you have the base-oil viscosity index (base-oil VI)! https://www.widman.biz/English/Calculators/calc-visc-index.html The latest table of the base-oil viscosity and VII content: Estimated base-oil dynamic viscosit... improver (VII) content of selected oils [Linked Image]
 
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