Viscosity Matters

[Grumpy Bear]

http://www.lube-media.com/wp-content/uploads/Viscosity-matters-WEB-ONLY-Sept19c_FINAL.pdf

 

Comments later. Give the group time to read and digest. Have a nice evening.  

[Grumpy Bear]

C120H242

n-icosahectane

 

 

Heavy end of a barrel of crude and the heavy end of Bitumen (Asphalt)

 

The light end is CH3 Methane.

 

Demonstrating that crude is a complex mixture of hydrocarbons that start as a gas and end as a solid in our environment. Lubricating Oil Bases fall in between in the liquid range. But what I hope one sees as well is that the heavier the SAE Grade the longer the carbon chain range which profoundly effects its physical properties. (Conventional Oils) The most obvious is its viscosity. 

 

Film thickness is tied to viscosity. Viscosity to carbon chain length. But it's also tied to the complexity of that chain. 

 

This is easy to demonstrate with the possible ranges of viscosity between the various base oil Groups. 

 

Group I's are cuts between 4 cSt and 32 cSt. Straight cuts off the column solvent refined and cold dewaxed but as nature produced them. 

 

Group II's have been "Hydrotreated" which means subject to some pressure and hydrogen rich atmospheres to 'saturate' the unsaturated molecules. Since the chain length is not affected, the range is very close to the same. 4 cSt to 30 cSt. 

 

Group III's however are HYDROCRACKED after hydrotreating. Hydrocracking does as the name implies. It makes small molecules from larger ones and restructures them into isomers. This shifts the carbon length to the left or towards methane and away from n-icosahectane. It also caps the possible viscosity are or near 8 cSt. GTL's are even lighter. 2 to 6 cSt. 

 

You can't make a *W30, *W40 *W50 *W60 *W70 from a Group III without a 'helper'. Okay, enough of that for now. 

 

The FIRST job of a lubricant is keeping parts from touching other parts.

 

Everything we consider past that is past that. Period. Full Stop. Until we can parts apart the amount of friction, the length of service, environment, ROI or anything else one can dream up as important....isn't. 

 

You have to have enough and you have to keep it under whatever conditions the machine is subject to. 

[Grumpy Bear]

From the opening link: 

 

[Quote] Let’s consider an example of how polymeric VI boosters are used in practice. Assume, you have got 150N API Group II base oil with KV40 = 28 cSt and KV100 = 5.2 cSt (VI = 109). If you add 15% olefin copolymer (OCP) type of VI improver, such as Paratone 8006, you will end up with a polymer-thickened product with KV40 = 83 cSt and KV100 = 12 cSt (VI = 140). So, the VI has increased from 109 to 140. How can you decipher that this is a polymer-oil blend and not a polymer-free 600N oil? The first thing to check is the flash point: polymer-thickened oils will have nearly the same flash point as the original base oil (150N, FP 220o C), which is much lower than the flash point of an equiviscous polymer-free base oil (600N, FP 270o C). The second useful check is the evaporative loss: polymer-thickened oils will exhibit nearly the same evaporative loss as the original base oil (150N, 15 wt.% Noack) which is much higher than the evaporative loss of an equiviscous polymer-free base oil (600N, 2 wt.% Noack) [Close Quote]

 

This same tool can be used when a Group III is blended with a Group IV or V of greater viscosity, another way to boost the viscosity of a low vis base. Both will have a higher flash point and lower NOACK than a bare back Group II thickened with a VM. Group II/III blends can be ferreted out with pour point. 

 

Point is, you can't hide from the chemistry. You can lie about it but not hide from it. You can cast doubts. But not hide. 

 

Why does it matter?

 

Later. I'm not even sure I have the gas to run this rabbit to the bottom of its hole.  

[Grumpy Bear]

From the opening link: 

 

[Quote] Even though the theoretical understanding of the VII action of various polymer classes and their effect on the lubricant tribology has advanced enormously, experience remains the best teacher in this largely empirical field. Nowadays, thinner oils are actively promoted to improve fuel economy. [Close quote]

 

It is also dominated by PROFIT MARGINS. 

 

The SAE requires four test to be met for just viscosity. HTHS, 100 C viscosity, Maximum Pumping viscosity and Maximum Cranking viscosity. 

 

[Quote] There are substantial differences between the various classes of VI improvers in terms of efficiency, shear stability, solubility, and of course, price. For instance, olefin-copolymer (OCP) and polyisobutylene (PIB) VI improvers have nowadays become a “plain-vanilla” type of VI improvement technology, with a primary focus on value-engineered products, while styrenic and polyalkyl methacrylate (PAMA) VI improvers are increasingly used in top-tier products. This fact proves that the viscosity data referred to in the SAE J300 still do not paint the whole picture: you can match all four viscosity readings and still see differences in product performance. [Close quote]

 

Even the SSI testing doesn't give you all the facts and as a bonus, it isn't published routinely and hard to get even on request. Example....

 

A fluids viscosity is tested at 100C and it passes. This oil is subject to intensive shearing for a period of cycles then retested. The percentage the viscosity falls is the SSI index. But this test does not tell you what the viscosity was while being sheared!  

 

OCP and PIB polymers 'stretch' under stress which lowers viscosity and some will 'break' leading to the loss indicated by the SSI test but the total loss isn't detected during this test. The ASTM D6616 HTHS does.

 

Same test carried out by the 150 C test but at 100 C and that number is also rarely publish and NOT an SAE Grade Requirement.

 

They don't test for it but your motor does!  

Okay they test, they just don't publish. 

 

For a motor using an oil with an OCP or PIB this shear down can be over 20%. One full SAE Grade while another oil using a Styrenic or PAMA stays within 0-5% of the 100 C result. Both pass thus meet the same SAE/ILSAC/ACEA and manufactures licensing. But they are very different in use. 

 

 

Edited March 9 by Grumpy Bear
Correct text

[customboss]

19 minutes ago, Grumpy Bear said:

viscosity data referred to in the SAE J300 still do not paint the whole picture: you can match all four viscosity readings and still see differences in product performance. [Close quote]

ABSOLUTELY TRUE  J300 does not reflect advanced base oils and other chemistries capabilities. 

[customboss]

PROBABLY BEST TRAINING VIDEO HES DONE. GO KERMIT.

 

Dr Ken Hope from CP CHEM is a colleague from days past specifically with RLI. He like me is retired now. 

 

Edited March 10 by customboss

[Grumpy Bear]

From the opening link:

 

[Quote] Nowadays, thinner oils are actively promoted to improve fuel economy. Keep in mind, however, that in a running engine, crankcase lubricant is always to some extent “diluted” by fuel. The degree of fuel dilution depends on the engine type and driving conditions. Stop-and-go city traffic is one adverse scenario most people are not even aware of. In the worst cases, oil may contain as much as 10-15% of fuel. Another adverse scenario is high-speed driving, such as stock car racing, where rich air-fuel mixtures are deliberately used to cool engines.

 

As a result of fuel dilution, motor oil easily goes one grade down: you start with a 5W-30 oil and soon find it diluted to a 5W-20 level. Oil also becomes thinner when the engine is heavily loaded and runs hot, for instance, while towing a trailer.

 

Some manufacturers tend to incorporate a greater safely margin in their formulations, setting the v100 target just in the middle of the respective viscosity grade and HTHS well above the permissible minimum value. Others try to push their products to the edge to max up fuel economy benefits. For instance, a 5W-40 with KV100 = 14.5 cSt will withstand 4-5% fuel dilution without falling off grade. A similar 5W-40 “enhanced fuel-economy” product with KV100 = 13.0 cSt will fall off grade already at 2% fuel dilution. Hence, in general, you are always safe to go one grade higher than the one recommended by your engine manufacturer, but never use thinner oils than recommended [Close quote]

 

*********************************************************

 

1.) OCP and PIB polymer shear in many price point commercial oils

2.) Large amounts of high MW weight VM's used in multigrades with wide values between the two registers.

3.) SAE 'Energy Conserving" grades hugging the viscosity basement of said grade.  

4.) Fuel dilution

5.) Load and rpm strain and stress driving #1 and #2. 

 

A case can be made with ease that two grades could be warranted. An energy conserving oil (i.e. Dexos1Gen2/3 or ILASAC GF-6) hugging the low end with wide spread (0W30 or 40 or 5W50) using a high shear VM combine with fuel dilution (cold city driving, fast road work, towing,  pour tune, GDI) would be one example. 

 

 

[customboss]

Here’s my overview of Boris’s paper when he was at Bizol. 
 

Boris Zhmud, Head of R&D, BIZOL Germany GmbH

Executive Summary:

This briefing document summarizes the key themes and important information presented in the "Viscosity matters" article. The central argument is that viscosity is a critical property of motor oil and other automotive lubricants, directly impacting engine operation, fuel efficiency, and component longevity. The article traces the historical development of motor oil classification, highlights the increasing importance of low-viscosity oils for fuel economy, and details the technical aspects of viscosity measurement and its implications for real-world engine performance. It also discusses the use of viscosity index (VI) improvers and the potential challenges associated with their use, as well as the impact of fuel dilution on oil viscosity. Ultimately, the article emphasizes the delicate balance required in formulating motor oils to ensure adequate lubrication across a wide range of operating conditions and the potential risks of using oils with excessively low viscosity.

Main Themes and Important Ideas:

1. Fundamental Importance of Lubricants:

• Motor oil and other fluids (automatic transmission fluid, hypoid gear oil, power steering fluid) are essential for the reliable operation of motor vehicles.
• "Without lubricants motor vehicles would not exist."
• Motor oil is vital for internal combustion engines, and an engine will not run without it. This understanding dates back to the earliest automobiles.

2. Historical Evolution of Motor Oil Classification:

• Early automobiles like the Benz Patent Motor Car (1886) used rudimentary lubrication systems.
• The Ford Model T (1908) introduced a splash oiling system, conceptually similar to modern systems.
• The Society of Automotive Engineers (SAE) established the first motor oil classification in 1911 (Specification No 26), initially based on specific gravity, flash, and fire points. More viscous oils were considered "heavier."
• Viscosity became the primary basis for SAE specifications in 1923.
• The latest SAE J300 specification, adopted in 2015, introduced new lower viscosity grades (8, 12, and 16) reflecting the trend towards improved fuel efficiency.
• SAE J306 specifications for gear oils have also been updated with new viscosity grades.

3. Viscosity and Fuel Efficiency:

• There is a direct relationship between lower High-Temperature High-Shear (HTHS) viscosity and improved fuel economy.
• "There exists a simple empirical relationship between the HTHS of motor oil used and fuel economy (FE) of the internal combustion engine..."
• The article provides an example: a change from 15W-40 to 5W-20 can yield approximately 5% fuel economy improvement, and moving to 0W-8 can provide an additional 5%.
• Fuel economy requirements are increasingly integrated into engine oil performance specifications (e.g., ILSAC, API, ACEA, OEM specifications).
• This trend drives lubricant manufacturers to formulate products with the lowest possible viscosity for a given SAE grade and to utilize synthetic base oils for their superior performance and consistency.

4. Defining and Measuring Viscosity:

• SAE J300 specifies four types of viscosity:Kinematic viscosity at 100°C (KV100)
• Maximum permissible viscosity for cold cranking (CCS)
• Cold temperature pumpability
• High-temperature high-shear (HTHS) viscosity
• SAE J306 for gear oils uses three: KV100, CCS, and cold temperature pumpability (HTHS is irrelevant for gear operation).
• KV100 is crucial for oil flow through engine channels.
• CCS and low-temperature pumpability ensure the engine can be started in cold conditions.
• HTHS viscosity guarantees adequate lubrication under high engine load and temperature where shear forces can reduce oil viscosity.

5. Importance of Maintaining Adequate Viscosity:

• Too high viscosity: May delay oil delivery and hinder heat dissipation. While not immediately fatal, it happens during cold starts.
• Too low viscosity: Far more dangerous, leading to insufficient oil pressure, rapid wear, piston/ring scuffing, seizure, and increased oil consumption.
• Oil pressure is critical for subsystems like hydraulic timing chain tensioners and variable valve timing (VVT) systems. Low oil pressure can cause these systems to malfunction, impacting engine performance, fuel economy, emissions, and potentially triggering the "Check Engine" light.

6. Multigrade Oils and Viscosity Index (VI):

• Nearly all modern automotive motor oils are multigrade (e.g., SAE 10W-40), providing performance across a wider temperature range.
• The "W" number indicates low-temperature performance (cranking and pumpability), while the second number indicates high-temperature performance (KV100 and HTHS).
• A greater difference between the two figures indicates a broader multigrade with a higher Viscosity Index (VI).
• A high VI is desirable as it signifies less viscosity variation with temperature.

7. Viscosity Index Improvers (VIIs) and Their Implications:

• Polymeric VI boosters are used to achieve higher VIs.
• Polymer-thickened oils can be identified by their lower flash point and higher evaporative loss compared to polymer-free oils of equivalent viscosity.
• "The conclusion from this example is that polymer thickening and VI boosting should be used with care: though it helps you easily tune product viscometrics, some other vital properties may be overlooked."
• Excessive use of polymers can compromise shear stability (hence the importance of HTHS and Shear Stability Index - SSI).
• Other potential issues include oxidative thickening and gelation in used oils.
• Different classes of VIIs (e.g., olefin-copolymer (OCP), polyisobutylene (PIB), styrenic, polyalkyl methacrylate (PAMA)) have varying efficiency, shear stability, solubility, and cost. Top-tier products increasingly use styrenic and PAMA VIIs.
• "This fact proves that the viscosity data referred to in the SAE J300 still do not paint the whole picture: you can match all four viscosity readings and still see differences in product performance." Conventional viscometry doesn't capture aspects like chemical stability of VIIs, their interaction with other additives, or their effect on oil film strength.

8. The Impact of Fuel Dilution:

• Crankcase lubricant is often diluted by fuel, the degree depending on engine type and driving conditions (stop-and-go city traffic, high-speed racing with rich mixtures).
• Fuel dilution can significantly reduce oil viscosity, potentially causing a 5W-30 oil to behave like a 5W-20.
• High engine load and temperature (e.g., towing) also thin the oil.

9. Safety Margins and Manufacturer Recommendations:

• Some manufacturers incorporate a greater safety margin in their oil formulations (higher KV100 and HTHS within the grade).
• Others push for maximum fuel economy with lower KV100 and HTHS, making them more susceptible to viscosity drop due to fuel dilution.
• "Hence, in general, you are always safe to go one grade higher than the one recommended by your engine manufacturer, but never use thinner oils than recommended." This highlights the greater risk associated with using lower viscosity oils than specified.

Conclusion:

The article clearly demonstrates that viscosity is a fundamental and multifaceted property of motor oil that directly influences engine health and performance. The ongoing trend towards lower viscosity oils for improved fuel efficiency necessitates careful formulation and a thorough understanding of the trade-offs involved. Factors like operating temperature, shear forces, and fuel dilution can significantly impact oil viscosity in real-world conditions. Therefore, adhering to manufacturer recommendations and understanding the implications of viscosity grades and the use of VI improvers are crucial for ensuring the longevity and reliable operation of modern engines.

[Grumpy Bear]

I'm going out on a bit of a limb here. Only because I have no idea how this will turn out. 

 

Since I got my Mitsubishi Mirage G4 off to such a stellar start (IMHO) and I fell into some unusual access I thought I'd start to track her path. Raven is her name. I'm going to post two graphs then below them ramble a bit 

 

 

 

 

 

This motor, in the USA, specs a SAE 0W20 oil and a 7,500 mile 'normal' OCI or a 3,750 "Severe OCI. 

 

Blackstone keeps a library of results for each motor platform providing what they call "Universal Average" that is normalized to a 5K mile OCK. The average of all miles, all OCI's and so on and so forth. The yellow line represents that value. So a linear line. When the provide a customer result this comes with it so the consumer has an idea of where he stands in the universe of his motors world of experience. A rough reference if you will. I have normalize all results to a 1K interval. This line represents the sampling of 0W20 spec oil even if there is some data spoilage the mainstream consumer will abide by the OEM recommendations. It is the best information I could source. 

 

The white line on orange diamonds is a lucky find. A fellow who chose to use Mobil 1 5W30 over a 45K mile period of 5K OCI's and sampled as often as he changed oil after an initial break-in pull and then subsequent 5K intervals starting at 20K, missing one at 35K the on until he discontinued his research at 45K. The trend line is a fourth order polynomial (best fit). 

 

The single red dot is Raven on my choice. 5W40. This is the 'out on a limb' part. I have no idea where this is going to go so I could be wiping egg from my face. But I like her first result. 

 

Thing is we have an opportunity to have a look at viscosities impact on wear as a primary causal effect. 

 

These charts are "Scatter Charts". No matter what my intervals are they will directly relate to all other data on a milage basis. So my results will track the polynomial average. Find Ravens' number and go straight up or down to the white line to find the comparison to the 0W20 result. Better is better, worse is worse. 

 

********************************************

 

Tidbits. Iron is used often as an primary indicator of wear in all sorts of studies. As can be seen in the 0W20 iron data, break-in lasted well beyond the 'sealing the rings phase. Looks like this: 

 

As long as wear is on the decline you remain in the 'Wear In" zone and as can be seen in the graph the start of "Normal Operation" did not begin until 30K miles passed under the test subject. Took 20K just to hit the knee of the curve. 

 

Trending is your friend and tracking trends will tell us the difference between "Wear-in", 'Normal" and "Wear Out". Onset will be seen best in the rearview mirror. Let's dance!! 

 

Edited March 16 by Grumpy Bear

[customboss]

Add this to our discussion of viscosity.  The study is OPEN for download. Read up. 

 

https://www.mdpi.com/2075-4442/13/4/137

 

 

[customboss]

4 minutes ago, customboss said:

Add this to our discussion of viscosity.  The study is OPEN for download. Read up. 

 

https://www.mdpi.com/2075-4442/13/4/137

 

 

 

 

Briefing Document: Engine Lubricant Impact on Light-Vehicle Fuel Economy Source:

 

"Engine Lubricant Impact in Light-Vehicle Fuel Economy: A Combined Numerical Simulation and Experimental Validation," Lubricants 2025, 13, 137. Authors: Fernando Fusco Rovai, Eduardo Sartori, Jesuel Crepaldi, and Scott Rajala Key Themes: The study investigates the impact of lower viscosity engine lubricants, with and without friction modifier (FM) additives, on the fuel economy of a light-vehicle with a spark ignition engine. It utilizes a combination of numerical simulation and experimental validation on a chassis dynamometer. The research aims to quantify the fuel consumption benefits of these lubricant technologies and assess the accuracy of a developed 1D simulation model.

Most Important Ideas and Facts:

• Growing Importance of Fuel Economy: The optimization of passenger car efficiency is crucial for mitigating greenhouse gas (GHG) emissions, driving the adoption of technologies that reduce fuel consumption and CO2 emissions.
• Engine Friction as a Significant Loss: Friction losses in internal combustion engines (ICE) constitute a substantial portion of fuel consumption, reaching around 10% of fuel energy in urban conditions and potentially 25% of fuel consumption and CO2 emissions after combustion.
• Low Viscosity Lubricants Reduce Hydrodynamic Friction: Lower lubricant viscosity decreases hydrodynamic friction, which is prevalent at higher engine speeds. However, it can increase boundary and mixed regime friction, especially at lower speeds.
• As the authors state, "Lower lubricant viscosity reduces hydrodynamic but increases boundary and, in lower magnitude, mixed regime friction of moving surfaces [2–6]."
• Friction Modifiers (FM) Mitigate Boundary and Mixed Friction: FM additives are essential in low viscosity lubricants to counteract the increased friction in boundary and mixed lubrication regimes by improving lubricant behavior at low film thickness.
• The study references Taylor et al. [3], who found that a 0W12 oil without FM caused more boundary friction than a 15W40 at lower engine speeds, but the inclusion of FM in the 0W12 "practically annulated the lower viscosity disadvantage below 1000 rpm (Figure 1b)."
• Combined Numerical and Experimental Approach: The study employs both 1D numerical simulation and experimental validation on a chassis dynamometer to assess the fuel economy impact of different lubricants.
• "In this work, the impacts of engine lubricants with lower viscosity and friction modifier additive in a light-vehicle with a spark ignition engine were numerically simulated and experimentally validated."
• Tested Lubricants: Three fully-formulated engine lubricants were tested:
• Baseline: 5W40 (OEM-certified, no FM)
• Proposal 1: 5W20 (lower viscosity, no FM)
• Proposal 2: 0W16 (lowest viable commercial viscosity, with 900 ppm Molybdenum FM)
• Experimental Setup: Tests were conducted on a large SUV with a turbocharged, direct injection, spark ignition flex-fuel engine in an OEM-certified emissions laboratory using a combined cycle (55% urban FTP75, 45% highway). Strict protocols were followed to minimize experimental uncertainties.
• Numerical Simulation Model: A 1D simulation model was developed in GT-SUITE, based on lubricant temperature and viscosity impact on engine friction. The model uses a viscosity ratio with a power index to estimate the change in friction mean effective pressure (FMEP).
• "A 1D simulation model based on lubricant temperature and viscosity impact on engine friction was developed and presented good experimental correlation in combined cycle for 5W20..."
• Experimental Fuel Economy Results:5W20: Resulted in a 2.9% lower fuel consumption in the combined cycle compared to the 5W40 baseline. Improvements were more pronounced in the urban cycle (FTP75), especially in the lower speed Ph2.
• 0W16 with FM: Achieved a 6.1% lower fuel consumption in the combined cycle compared to the baseline, showing significantly greater benefits than the 5W20. Again, the urban cycle (Ph2) showed the largest improvement.
• Numerical Simulation Fuel Economy Predictions:5W20: Predicted a 2.7% lower fuel consumption in the combined cycle, showing good correlation with the experimental result.
• 0W16 with FM: Predicted a 3.8% lower fuel consumption in the combined cycle, significantly underestimating the experimental result.
• Discrepancy with 0W16: The authors attribute the larger difference between simulation and experimental results for the 0W16 lubricant to the fact that the numerical model primarily considers viscosity effects and does not fully account for the additional friction reduction provided by the FM additive.
• "The numerical simulation advantage was 38% lower than experimental results for 0W16 that contains friction modifier, as the additive impact was not considered in this mathematical model."
• Temperature Effects: Lower viscosity lubricants, particularly 0W16, tended to have slightly lower oil sump temperatures during the tests, potentially due to reduced friction. The benefit of lower viscosity was more pronounced at lower temperatures, especially for 0W16 during the cold start phase (Ph1) of FTP75.
• NMOG Emissions: Measurements of non-methane organic gases (NMOG) did not indicate a significant increase in lubricant consumption with the lower viscosity proposals, suggesting no immediate negative impact in this area, though further investigation is recommended.
• Wear and Durability Concerns: While the in-cycle tests did not reveal abnormal engine behavior, the authors emphasize the need for extensive investigation into engine wear and durability when using ultra-low viscosity lubricants like 0W16 across various operating conditions.

Quotes:

• "The substitution of a baseline 5W40 lubricant by a lower viscosity 5W20 proposal resulted in 2.9% lower fuel consumption in a combined cycle. This fuel consumption improvement is enhanced to 6.1% with a 0W16 lubricant with friction modifier."
• "Friction losses are a significant share on car fuel consumption. On urban conditions, ICE friction losses are around 10% of fuel energy. As the losses occur after combustion, they represent as much as 25% of fuel consumption and CO2 emissions [1,2]."
• "The clear low viscosity lubricant frictional losses reduction in the hydrodynamic regime must be balanced with the concern of its potential higher engine wear in mixed and boundary lubrication regimes affected by asperity friction..."
• "Closer simulation results for 5W20 demonstrates good correlation between the mathematical model, based on lubricant viscosity, and the experimental results. It is important to emphasize that both 5W40 (baseline) and 5W20 proposal do not have FM."
• "The simulation with 0W16 considered only the lubricant viscosity impact but the FM additive in this lubricant can explain the considerably higher simulation deviation, which demand mathematical model improvement to be performed in the future."

Conclusion:

The study provides strong evidence for the fuel economy benefits of using lower viscosity engine lubricants in light-vehicles. The experimental results demonstrate significant reductions in fuel consumption with both 5W20 and, particularly, 0W16 with FM. The developed numerical simulation model shows good predictive capability for lubricants without FM, but requires further refinement to accurately account for the effects of friction modifier additives. While the fuel economy advantages are promising, thorough investigations into long-term engine wear and durability with ultra-low viscosity lubricants are crucial. For GRUMPY BEAR......LOL

Edited March 22 by customboss

[customboss]

Lake Speed Jr  and Rafe on new cylinder tech  and  how engine makers/builders re getting to lower vis lubricants......

 

 

 

Edited March 23 by customboss

[Grumpy Bear]

45 minutes ago, customboss said:

Lake Speed Jr  and Rafe on new cylinder tech  and  how engine makers/builders re getting to lower vis lubricants......

 

 

 

Not sure what I do with that. Spray bore of that course a texture is Porsche, MB and Ford Mustang V8 Gen III technologies and yes they are worming there way into the mainstream. Additionally, the warning is pinned to a particular surface finish (80ish Rvk and a sub 10 Rpk) used in those applications. In point of fact are not present in even 280 grit chrome ring motors! Ergo there isn't a blanket statement that can be used to cover the entire field. Honda and Toyota have used *W20 oils with great success in iron liner motors. GM whiffed the ball so hard it was laughable with the Vega. Fact, about 4 other casting and liner types were used without meaningful success before spray bore tech. Jury is out in my courtroom....

 

I have a five auto/truck motors and about that many motorcycles of which zero are spray bore motors. Given their success rate and longevity I will try with earnest to avoid them for the short remainder of my life. LOL. 

 

Guess it would be a good idea, now that you bring this up, to quiz sales on the EXACT motor specifics. If they can't or are unwilling....I'm not buying, yea, even if I walk. 

 

Now, last thought. Viscosity is tied to finish and if one can get a seal on a very smooth bore/ring face then a low viscosity oil is the call. MOFT is about 'asperity height'. (all other things equal, speed, load, yada yada yada) 

 

Chrome 280 bore might look like the top below. Both have an Ra of 2.4 um. Lower is more what a chrome finish looks like after break-in. A Moly ring 380/420 grit is a finer Ra but represented best in the upper as well. Just shallower Rvk and shorter Rpk. Newer DLH coating systems that are 'slide honed" look more like the lower with the finer 400 ish initial and the knocking the RpK off with a 600 or even 800 grit pad. None of these are particularly finicky. This new spray system has allot of smooth peak area and a VERY DEEP valley. Not heavy viscosity friendly. 

 

 

Off to Ford killing your warranty for the Gen III Mustang motor when using high vis oil. It will use oil and they will not, can not fix that. It's structural.  But it should stop using once to change oil to recommended value. The warranty is not invalid because it used oil but because it used oil it DETONATED to junk. They won't and should not fix that. 

[customboss]

19 minutes ago, Grumpy Bear said:

GM whiffed the ball so hard it was laughable with the Vega

Aluminum we love !!!NOT 

[Black02Silverado]

Interesting discussion. Full of great information.