Really Good Motor Oil Information

There is a blog about motor oils that is simply second to none and I want to share that with you: https://540ratblog.wordpress.com/

The information itself is something that you have to read through, compare and comprehend to fully understand his testing methodology. I have been studying his information now for about a year and it has certainly helped me to understand that for all of the Madison Avenue hype on motor oils, (which if you noticed lately you don’t see the amount of advertising that you once did) a lot of the claims that they make are really bogus.

From “Tech Facts, Not Myths”

MOTOR OIL ENGINEERING TEST DATA

The date June 20, 2013 just above, is the date this Blog was first started, NOT the date of the information included. It is regularly updated with the latest information, as indicated by the date several paragraphs below.

NOTE: The motor oil wear protection test data included in this Blog is from performance testing of many different motor oils, which shows how they compare relative to each other. The focus is on the motor oils themselves. Therefore, the resulting comparison data applies to ANY engine that uses the oils included here, no matter if the engine is used for racing, daily driving, grocery getting, watercraft, or any other activity.

Before we get into motor oil tech, let’s briefly touch on a little background info. That way people will better understand who I am and where I’m coming from. Here are my credentials:

Mechanical Engineer

U.S. Patent Holder (Mechanical device designed for Military Jet Aircraft)

Member SAE (Society of Automotive Engineers)

Member ASME (American Society of Mechanical Engineers)

Lifelong Gear Head, Mechanic, Hotrodder, Drag Racer, and Engine Builder

I’m a working Professional Degreed Mechanical Engineer, and Mechanical Design Engineering is what I do for a living. A Mechanical Engineer is clearly the most qualified Engineer to test motor oil that was formulated by Chemical Engineers, for wear protection capability between mechanical components under load. But, as you will see below, the following write-up is not intended to be a chapter out of an Engineering textbook. And the intended audience is not other Engineers. There are no formulas, equations, charts or graphs. The intended audience includes Mechanics, Automotive Enthusiasts, Gear Heads, Hotrodders, Racers and Engine builders. So, it is written in normal everyday spoken language, rather than overly technical jargon. That way, it will be the easiest to follow and understand by the widest possible audience. And some key points will be “intentionally” reiterated from time to time as the information presented here progresses, to emphasize those points.

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** This Blog now has over 255,000 “views” worldwide!! Surpassing the incredible quarter of a million views milestone, clearly shows how popular this Blog is all over the world.
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Its view count has been increasing by nearly 10,000 views per month. And the highest number of views on a single day took place on November 6, 2015 when 996 views were recorded. Of course simply listing the number of views by itself, is not intended to indicate validation of the test data (validation is shown throughout the Blog). But, indicating the number of views does show that an enormous number of people worldwide recognize the value, understand the importance, and make use of the motor oil test data FACTS included here, that cannot be found anywhere else. And as a result, they are posting and sharing links to this Blog, all over the world.

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!! THE INFO ON THIS BLOG WAS LAST UPDATED ON January 5, 2017 !!

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• The view count above, was updated.

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NOTE: All oils used in the testing here, were purchased in the U.S.A., unless otherwise specified.
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BRIEF TECH INTRO:
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The absolute MOST important capability of any motor oil, is to PREVENT WEAR!!! And that capability is determined by its proprietary additive package formulation which includes the extreme pressure anti-wear components. Everything else a motor oil does, comes AFTER that. And everything else a motor oil does, is in “back-up support” of preventing wear. For example, preventing acid formation, ultimately prevents wear. Preventing deposit build-up, maintains oil flow and lubrication, preventing wear. Preventing sludge build-up, maintains oil flow and lubrication, preventing wear. Minimizing air bubbles/foam, keeps the oil mostly liquid oil which is required for proper lubrication, preventing wear, etc, etc. You get the idea.

Motor oil exists in “TWO” forms inside an engine, under which it needs to protect against wear. They are as follows:

1. “Liquid oil” which can be defined as oil thick enough to drip, run, pour or flow.

2. An “oil film” can be defined as a coating of oil too thin to drip, run, pour or flow.

An example of oil in “liquid” form, is in the rod and main bearing clearance, where the incompressible hydrodynamic liquid oil wedge is formed between the crankshaft journals and its bearing shells, as the oil is pulled in by the rotating crankshaft. Oil pressure does not keep the parts separated. Oil pressure serves only to supply oil to be pulled in between the parts.

The fact is, liquids cannot be compressed to allow metal to metal contact, so parts are kept separated and no wear or damage can take place. In liquid form, it does not matter what the oil’s viscosity is, what brand it is, how hot it is, nor how much it costs. Because in the incompressible liquid form, all motor oils provide the same unsurpassed wear protection.

A mere “film of oil”, is the last line of defense against metal to metal contact, and the subsequent wear and/or damage that can follow. An example of an oil film is between non-roller flat tappet lifters and cam lobes of traditional pushrod American V-8 engines, or in DOHC engines between the cam lobes and non-roller type followers they may use. But, it is most critical in pushrod engines which typically use large single intake and single exhaust valves with stiff valve springs, compared to DOHC engines which often use two smaller intake and two smaller exhaust valves with lighter and smaller valve springs. In these locations, no incompressible hydrodynamic liquid oil wedge can be formed because of the wide open parts configuration. And the oil present is simply pushed aside, leaving only a film of oil between the parts with a very thin, highly loaded “line contact” between the parts.

Since “all liquid oils” are incompressible and thus provide unsurpassed wear protection, there is nothing to test for comparisons between different oils in liquid form. My Engineering Tests evaluate the much more critical oil film strength/load carrying capability/shear resistance, which as mentioned above, is the last line of defense before metal to metal contact takes place.

No reliable comprehensive information had been available for this capability comparison, until I began my dynamic motor oil testing, under load, at a representative operating temperature. I perform those Engineering Wear Protection Tests to find out where the motor oil film strength, load carrying capability, shear resistance “limits” are for each individual motor oil. That’s what we compare. The higher the limit, given in PSI, the better the wear protection.

“Film strength, load carrying capability, shear resistance” performance is where motor oil wear protection capability VARIES WIDELY depending on a given oil’s proprietary formulation. And it is at the film strength level, where oils can be evaluated and compared, for those different wear protection capabilities. This is where good oils are separated from not so good oils.

Only dynamic wear testing under load, at a normal operating temperature, can reveal how the various motor oils truly compare regarding wear protection. So, that is precisely what I do to discover the facts. And that is why merely looking at an oil’s spec sheet is worthless. A spec sheet cannot show you an oil’s wear protection capability, because Engineering tests and real world experience have proven over and over again, that the zinc level does NOT matter. That is only a MYTH that has been repeated a million times until people just assume is true, which it is not. Only the psi value from my test data will actually show us how motor oils truly perform regarding wear protection.

My test data EXACTLY matches real world severe over-heating experience, real world Track experience, real world flat tappet break-in experience, and real world High Performance Street experience. Test data validation doesn’t get any better than this.

Bottom Line: You simply cannot find better information anywhere else, on “THE” most critical motor oil capability, which is wear protection. For all the comparison data, see my Wear Protection Ranking List below in this Blog.

But, there could be some confusion for people who do not actually read my entire Blog. My test data on wear protection is generally aimed at High Performance and Racing engines that are capable of pushing motor oils near their limits. So, knowing how capable various oils truly are, can be critical. It is of course also for people who simply want to know what oils will provide the best possible wear protection for their engines, even if they don’t technically push their motor oil near its limit.

However, for ordinary daily driver vehicles, the oil used is nowhere near as critical as it is for High Performance and Racing engines. So, a normal daily driver vehicle may operate just fine for the life of the engine on say a low performing 60,000 psi motor oil. But, a High Performance or Racing engine may require a high performing 90,000 psi or higher motor oil, to avoid wear and/or damage. It just depends on how much loading the engine puts on its motor oil.

And the better performing the oil, the higher the reserve wear protection capability, also called margin of safety, which means capability beyond what is actually required. If you have a problem at some point, say an engine component starts to fail, or the oil level gets low, or there is an overheating condition, or you increase the power level dramatically, etc, etc, then extra reserve wear protection capability could save your engine. So, people have to decide for themselves how much wear protection capability they feel comfortable with for any given engine build. And since you have to buy oil anyway, why not select a better performing motor oil while you are at it?
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Additional motor oil technical info:
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Oil is not the same temperature throughout a running engine, the highest oil temps will typically be found in the incompressible “liquid” oil wedge formed as the oil is pulled into the clearance of the rod and main bearings. That is because, the oil at those locations is being heavily loaded on the power stroke, while at the same time, being sheared. Oil at these locations can be 50* to 90* hotter than sump temperatures.
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During the very brief time interval that oil is flowing through the rod and main bearings, most oils will momentarily reach and exceed their thermal breakdown points. And the cooler the oil starts out, the lower the max temp it reaches there. This is where oils with a higher onset of thermal breakdown point, offer some benefit. Because the less often an oil reaches its breakdown point, and the lower the max temp reached above that point, the longer its capability will remain near new oil level. This means that oils with higher onset of thermal breakdown points, can go longer between oil changes, with regard to thermal deterioration. However, oils with more modest thermal breakdown points can also be used without issue, as long as reasonable oil change intervals are followed, to stay ahead of any significant thermal deterioration.
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The oil on the cylinder walls is not subjected to the burning combustion temperatures as some might think, because very nearly all oil has been scrapped off the cylinder walls by the oil rings, and is not present during combustion. If any significant amount of oil was still on the cylinder walls during combustion, the exhaust pipes would be blowing blue smoke.
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When the piston is at TDC, the cylinder walls are coated with oil from all the oil spraying and flying around inside the crankcase. But, as the piston moves downward, the piston skirt scrapes off excess bulk oil, and the lower oil ring of a multi-piece oil ring, scrapes additional oil off the cylinder wall like a squeegee scraping water off a windshield. So, there is a layer of liquid oil between the piston skirt and the cylinder wall (its thickness depends on the piston to cylinder clearance), not just merely an oil film like you would see between a non-roller flat tappet lifter and its cam lobe. And any oil the lower oil ring doesn’t scrape off, the top oil ring of the multi-piece oil ring, will scrape off, directing it through the oil ring expander/spreader and through the oil holes in the piston.

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Piston ring spring tension against the cylinder walls is NOT what seals the rings against combustion, like most people think. There is no possible way that a mere few pounds of ring spring tension alone, could keep the rings in proper contact with the cylinder walls during the high pressure of combustion. The fact is, rings are kept in contact with the cylinder walls during combustion primarily by the tremendous combustion pressure itself, which is typically well over 1,000 psi, depending on the particular engine. The rings’ spring tension does keep the rings in contact with the cylinder walls enough to direct the high combustion pressure through the ring side clearance above, and then on behind the rings’, to their inside diameter back clearance. And it is this force “behind the rings” that presses the rings out against the cylinder wall with enough force to seal the combustion pressure during the power stroke (some racing pistons have gas ports behind the rings just for this purpose). That is why proper ring side clearance and back clearance are very important, as is free ring movement in the pistons’ ring grooves. To ensure free ring movement and make sure that they don’t get gummed up and stuck in the piston ring groves, it is important to use quality fuel and to change the oil at reasonable intervals.
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And remember, cylinder walls are in direct contact with the coolant on their outer surface. So, the cylinders are the most directly cooled parts of an engine, meaning the oil side of the cylinder walls are not anywhere near as hot as many people might think.
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An ideal oil sump temperature range is between 215*F and 250*F. If your sump temperature runs hotter than this range, you should add an oil cooler, or upgrade your oil cooler, if you already have one. This range is hot enough to quickly boil off the normal condensation that always forms during cold engine start-up, before that water dilutes the oil.
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And that range is cool enough to do three things:
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1. It is cool enough to keep the oil’s wear protection capability at the highest level achievable by that oil.
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2. It is cool enough to provide critical cooling for engine components, which of course are directly oil cooled. Remember, engine components are only indirectly water cooled.
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3. It is cool enough to keep most oils below their onset of thermal breakdown point.
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But, motor oils do NOT stop working the instant they reach their onset of thermal breakdown point. However, it is not a good idea to run oil above its thermal breakdown point for extended periods of time. Because that will degrade its capability more and more as time/mileage goes on.

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