Synthetic oil bad in a lawnmower? Any truth in this self proclaimed experts statements?

Let's not forget the if you are going from conventional oil to synthetic you must first run semi synthetic then if no leaks or oil usage you then can run synthetic. However be careful cause synthetic oil will damage seals after use of conventional oil.

You can't use synthetic oil if you used conventional oil for the early part of engine life.

Must flush engine first before you use synthetic.

Do not use 0w in Louisiana as a 10w will protect better in heat.

These are a few misconceptions I heard working at dealership.
 
How are we defining "synthetic" here?

"Synthetic" made from group II and III base stocks which are just highly refined petroleum/hydrocarbon based/GTL or group IV? Perhaps in this instance the actual chemistry may come into play.
 
Toyota has “lifetime” ATF fluid. Lawnmower you can toss it and buy a new one…. Little different story for a car transmission…
When I killed my 1981 mower hitting the bolt, I went on Kijiji (Canadian Craigslist) and bought a 99 Toro for like $150. It's not new by any means and smoked on startup where the 81 didn't, but it runs good and used no oil. The seller had changed the plug and air filter and I believe the oil at some point. I believe in getting lots of use out of stuff.
 
Let's not forget the if you are going from conventional oil to synthetic you must first run semi synthetic then if no leaks or oil usage you then can run synthetic. However be careful cause synthetic oil will damage seals after use of conventional oil.

You can't use synthetic oil if you used conventional oil for the early part of engine life.

Must flush engine first before you use synthetic.

Do not use 0w in Louisiana as a 10w will protect better in heat.

These are a few misconceptions I heard working at dealership.
Those are among the many common myths.
 
Briggs & Stratton actually went to a “no oil change” model with their mower engines. They come from the factory with full synthetic, you never change it and when the engine grenades you just buy a new one.

A friend of mine is a lawn mower tech at a repair shop. The class he had to take on this B&S said the average home owners do not want to worry about maintence. They want to pull the rope, mow, and then sit their fat ass back down.
These engines are rated for only like 250 hrs before they are junk and the average home owner replaces their mower every 3-5 years.
I sell my Honda lawnmower every 12 years.
 
Honda engines are developed, tested and certified with petroleum based motor oils as a lubricant. Synthetic oils may be used; however, any motor oil used in our engines must meet all oil requirements as stated in the owner’s manual. In addition, recommended oil change intervals must be followed.

I love this kind of answer. Note, it does NOT say you should not use synthetics, only that they need to meet all oil requirements.

I have a 1931 Model A Tudor. The Instruction Book (owner's manual) says, "Only high grade engine oil should be used in the engine...It should have sufficient boy so that the pressure between the two bearing surfaces will not force out the oil and allow the metal to come in actual contact." Okay, in 2021 what does that mean? To some it means non-detergent straight weight oil since that is what was available in 1931. To me it means a full synthetic 10w-30 or 10w-40 oil. In any case, Ford also recommended 500 mile oil changes. The engine has no oil filter and the carburetor has no air filter. I cannot ever see a possibility that a better oil could be worse for an engine.
 
LOL I have a Sears B&S Mower. 6.5 HP its close to 16 years old only fill it with leftover Full Synthetic 5W-30 and 10W-30 it runs great how could that be? Don't believe all the BS some of these oil experts give you!
 
I have a 1931 Model A Tudor. The Instruction Book (owner's manual) says, "Only high grade engine oil should be used in the engine...It should have sufficient boy so that the pressure between the two bearing surfaces will not force out the oil and allow the metal to come in actual contact." Okay, in 2021 what does that mean?
It means to use an oil thick enough to keep an adequate oil film thickness so there isn't metal-to-metal contact. They were "thickies" back in the 30s ... ;):D
 
Briggs & Stratton actually went to a “no oil change” model with their mower engines. They come from the factory with full synthetic, you never change it and when the engine grenades you just buy a new one.

A friend of mine is a lawn mower tech at a repair shop. The class he had to take on this B&S said the average home owners do not want to worry about maintence. They want to pull the rope, mow, and then sit their fat ass back down.
These engines are rated for only like 250 hrs before they are junk and the average home owner replaces their mower every 3-5 years.
Not changing lawnmower engine oil makes Baby Jesus cry.
 
I have a mower that is now 25 years old. Techumseh engine. I think 6.5 hp. Use 5-30 syn. Changed oil maybe 5 times. Runs great. It has high wheels and I use it for high grass and brush on the property. I expect it to last at least another 10 years or more.
 
Pretty sure there is 0W30 Helix Ultra Low SAPS GTL based oil in my mower right now. Not sure the mower needs an oil with a VI of +200. but it can't hurt...

And I have loads of it in the shed. so that's wheat it gets (once a year)
 
I've used Royal Purple Hmx 5w30 and this past summer, I was using Amsoil 0w40.

No issues using synthetic! 😎👍
 
"What people fail to appreciate is engines are designed for a specific type of oil .
No they aren't. Engines but be tolerant of a wide range of viscosities because of the impact ambient temperature has on it. This is the largest single factor in impacting what viscosity the engine sees when it is started.
That includes the size of oil holes so that the right amount of oil will flow through them to do the job required and there will be sufficinet oil pressure left in the system to lubricate parts further down stream of the oil pump.
Wrong.

Pressure is the artifact of resistance to flow. We see pressure on the gauge because the positive displacement pump is attempting to cram a specific volume of oil through the system. The heavier that oil is, the more difficult this is, so the artifact is increased pressure. The amount of pressure required reduces as the oil thins with heat, which is why hot oil pressure is lower from cold oil pressure.

When the oil is extremely thick, this can result in the pump going into bypass, which means some of that volume is shunted back to the feed-side and not forced through the engine.

Oil feed orifices are designed to bleed-off the necessary volume from the main gallery(ies) to feed their branches. So for example, on a pushrod engine, the feeds to the branches that feed the lifters and pressurize/lubricate the lifter bores are sized for that purposes are considerably smaller than the main gallery itself.
They also fail to understand that the flow charasterisc of oil under pressure is totally different to oil flow under gravity which is how the numbers on the front of the bottle are measured.
Oil is pumped, so "flow" is not important. Oils pumps are positive displacement, which means that each turn of the gears displaces a specific amount of oil. How that oil flows under gravity is irrelevant to that function as long as the oil can make its way up the pick-up. In a "sling" situation (small B&S engine) pump bypass doesn't even come into play because there isn't one.
So all that the numbers on the bottle actually tell you is how the oil will drain back down the drain holes to the sump .
No, the numbers on the bottle tell us two things:

1. The number in front of the W (Winter rating) of the lubricant is the ability for the oil to:
a. Make its way up the pick-up tube; be pumpable. This is MRV
b. Have a minimal impact on the cranking speed of the engine. This is CCS

2. The number after the W is representative of the "hot viscosity" of the oil and is measured at 100C. Each grade has a range assigned to it.

How the oil will "drain back down the drain holes" isn't factored into this scenario. The 100C figure is used to determine the amount of "cushion" in hydrodynamic situations, HTHS tells you that visc under higher temperature, and high shear, and the other figure, the Winter rating, tells you whether the oil is appropriate for the prevailing ambient conditions/starting temperature.
So for instance a synthetic oil that flows faster & easier will not provide enough oil to the last 2 journals on a strait 8 engine because all of the pressure will bleed off lubricating the first 6 cylinders .
That makes zero sense. The oil pump doesn't know, or care, whether the oil is conventional or synthetic, as long as it can pump it, it will. Since an oil pump, not on the relief, displaces the same volume of oil per revolution, even the viscosity is mostly irrelevant here. While a lower viscosity oil will increase bearing side-leakage an engine would need to be completely destroyed; bearing clearances would have to be past "toss a rod through the side" and you'd have no oil pressure in the scenario he's trying to conjure up.

Viscosity is viscosity and doesn't depend on whether the oil is conventional or synthetic as well. A 5w-30 synthetic behaves the same as a 5w-30 conventional.
Assuming cylinder 1 is closest to the oil pump, the slippers on it will have little rivers all through them because it got too much oil by volume because to use the synthetic oil the oil holes in the crankshaft need to be smaller because the oil flows freer .
Again, wildly incorrect. A synthetic and conventional oil of the same viscosity flow the same, and the engine would have to be well beyond the ability to run for clearances to be large enough to allow all of the oil volume to escape. Of course the artifact of that would be no oil pressure. Engines aren't designed around conventional or synthetic or even a particularly viscosity, but they may have a certain hot viscosity in mind as part of the bearing design. For example, an engine designed to run on 0w-16, 0w-12 or 0w-8 will have wider bearings because of the greatly reduced HTHS viscosity of the lubricant. Because of the reduced load carrying capacity of the lubricant, the bearing area must be increased to prevent metal-to-metal contact.
It takes years for very experienced engineers to design & test the lubrication system in anything to ensure it all works properly with the lubricant it was designed t & tested with.
And yet here you have Ford that spec'd both 5w-20 and 5w-50 for the same engine, lol. Engines are incredibly tolerant (necessarily so, due to the impact temperature has on viscosity, as outlined earlier) of a wide range of viscosities and as long as you don't use an oil with an inappropriate Winter rating (a 20w-50 when it's -25C vs a 5w-50) and don't go thinner than the allowable range (don't run a 0w-12 in an xW-20 application) the engine isn't going to care.
Then Joe Idiot comes along and thinks just because some race driver, big brested bimbo, whoever pops up on TV and says this stuff is better it will automatically make whatever they put it in run forever .'
A red herring, strawman and generous hyperbole all wrapped into one here, oh my! No response warranted for this detour.
Some times it might make no difference and some times it will
If it makes no difference then the user is pouring money down a hole & wasting the planets resources
If it does make a difference then that door swings both ways
Some times it will be better but most times it will be worse.
Gross generalizations and wild speculation, not worth addressing, it isn't even clear what he's addressing here.
However Joe Idiot never take responsibility for his own stupidity and will blame anything else other than him using an unsuitable lubricant .
Barnets got blasted from pillar to post because their clutch plates were slipping all over the place then after several years it was found that it was the owners shoving fully synthetic oil into their motorcycles that was causing the clutches to slip .
It would have had nothing to do with the oil being synthetic or not and would be due to the oils having friction modifiers in them (which energy conserving oils do). Motorcycle oils are not friction modified, the reason of course is shared sumps. There are plenty of full synthetic motorcycle oils that are wholly appropriate.
A similar story with NSK who copped a ton of warranty claims for excessive wear in roller big end bearings and crankshaft bearings
Same story, the freer flowing synthetics floated the rollers so they slid on the outer race rather than rolling .
This was a particularly big problem for Ducatti Desmo engines and to a lesser extent Harleys , made more confusing to Joe I Know More Than The Design Engineers , as latter models used synthetic oils so it must be OK to use it in older modles , well it was not ."
Again, synthetics are not "freer flowing". While they often have a better Winter rating, this has nothing to do with operating viscosity. Not understanding the subject and then trotting out what amounts to urban legend isn't helping here. Using an oil not designed for motorcycle and shared sump applications can be problematic, but whether that lubricant is conventional or synthetic is wholly irrelevant.
"IF you don't understand the basics then all you can do is put blind faith that what some one else has said is factually correct .
And yet here we have somebody who clearly doesn't understand the basics 🤷‍♂️
As you are totally unwilling to put in the work to educate yourself then you will never actually understand how lubrication works.
Given the above observation, that's quite an ironic statement.
I started my learning curve back in 1972 in the final years of my degree with a 2 hour lecture once a week for 13 weeks.
So that is 26 hours of face to face lectures + 13 more of tutorials + 13 more of practicals + 51 of pre lecture back ground reading before lectures.
How many hours have you spent on face book ?
And yet he still doesn't understand viscosity. Clearly, this was money wasted if that's what was supposed to be learned.
As for mower engine as was previously stated is all using a synthetic or semi synthetic will do is cost you more money .
But if it makes you feel good then do it all it will do is waste your money .
But he said it will flow "too good" and explode, what's this pedal back? Now it's just going to cost more money?
While their history goes back decades fully synthetic oils were developed commercially for F1 racing where spending $ 1000 / gallon on oil is petty cash.
Nope, they were developed for cold weather (arctic) and jet engine use, as conventional oils wouldn't hold up in turbine applications, oxidizing rapidly and breaking down. The Germans also developed the Fischer-Tropsch process during WWII, employing coal gasification to produce both fuel and lubricants because they were resource constrained. This process is now employed by Shell to produce their GTL synthetic base stocks and various other products from methane.

AMSOIL was started by a pilot who saw the superior characteristics of the synthetic lubricants developed for turbines and worked with Hatco to develop the first API-approved synthetic lubricant for automotive applications. This was followed by Mobil (Mobil 1) whose history of developing arctic and jet turbine oils using synthetic base stocks resulted in them using that knowledge to develop one for automotive use.
The engines in F 1 are pushed to their max they run at a lot higher temperatures than you mower ever will and every part has been cut down to the absolute minimum weight that will hopefully stay together for the length of a race and the manufacturing tollerances are substantially tighter than your mower ever will plus the oil plays a massive part in cooling the engine , or rather keeping the internals at a constant temperature , again totally irrelevent to an ir cooled mower engine and requires a bit of maths. Viscious friction robs power from the tailshaft so anything that can reduce it is a big + in racing.

Oil plays a tremendously important role in cooling an air cooled engine, as you don't have any coolant, so the only thing taking heat away from parts is the oil.

Not sure what F1 has to do with this, it is far from the only racing venue to employ synthetic lubricants, they are used universally in everything from drag racing to 24hr races, Nascar....etc.
When we raced speedway all of the engines run total loss oiling and you do notice the difference in responce between that and the same engine mounted into a Hagon frame with an oil tank for short circuit
Synthetic oils they stayed as an exotic item even during the oil crisis of the 70's when I was in college . untill California tightened emission laws then all the major engine makers found that the thinner oils allowed the engine to crank faster so the first cylinder to do a full induction cycle fired reducing the unburned fuel passed out the tail pipe thus meet the starting emissions tests for almost no developement costs.
The engines were run to destruction & oil galleries modified where necessary.
The oil companies were then told we want engine oils with these properties of the fully synthetic oils for our production engines but we will only pay $X / gallon for them .
Thus the semi-synthetic ( and that name is total BS as the oil is not synthetic & never was ) oil was born by stripping the dreaded "Dino oil" into some componant parts then recombining them in proportions that would not normally happen and that is part & parcel of the normal processing of normal oils .
All that the oil companies did was add a couple of extra distillation processes to the regular processing .
Wow, this guy should write fiction, he's much better at it than giving oil advice.

Synthetic oils were a far cry from "exotic" once Mobil 1 and AMSOIL became available. The ability to improve conventional base oil quality (Group II) and improvements to PPD's and VII polymers was a natural evolution of lubricants and in no way depended on synthetics. Synthetic oils didn't see any form of wide adoption until the long life approvals were developed in Europe and they worked to extend drain intervals, which necessitated the use of PAO to hold up.

GM developed a "Corvette" spec, which was carried by Mobil 1, and GM and Mobil had a development partnership that benefited both parties.

Semi-synthetics were borne of the philosophy of providing some of the advantages PAO-based synthetic offered (better low temperature performance, greater oxidation resistance...etc) while keeping the cost down. Ergo, some synthetic base stocks were blended in with conventional base stocks which improved the overall performance. There's nothing BS about the name.

He seems to be wildly confused on the different base oil tiers and how that applies to oil labeling.

Group I is the lowest (solvent refined) base oil. Introduce hydrocracking and hydroprocessing and you get a purer end product with lower wax, which in turn has better cold temp performance and oxidation resistance, this is Group II. Refinements to this process have resulted in Group II+, which is an unofficial designation. Severe hydrotreating results in a very pure base oil with a higher VI and even better oxidation resistance and low temperature performance, this is Group III and is considered synthetic in most parts of the world that aren't Germany.

A semi-synthetic can be mixed with Group III, PAO, POE or AN's or a combination of those products. There is nothing that dictates how it is blended.

Modern synthetic oils of course are a blend of multiple bases, the slate for which includes:
1. Group III
2. GTL
3. PAO
4. POE
5. AN's

Mobil products are typically a blend of the bottom 4, while Shell synthetic oils typically use #2, there are still lubricants where they appear to use their Group III base (XHVI) oils. Even though GTL technically falls under the Group III category, it's performance is slotted between your typical Group III and PAO.
True synthetic oil, created by reacting gasses together under pressure is a different animal but you won't find it at your local discount car parts shop.
I assume he's trying to refer to PAO, which is produced using ethylene gas. This is still something that comes out of the distillation tree, but the production of the building blocks to produce PAO through this process means it has absolutely no slack wax in it and thus has extremely good cold temperature performance and oxidation resistance. These base oils have high natural VI's, which means less VII polymer is needed.

Mobil 1 EP 0w-20 is a predominantly PAO-based lubricant. Most commercial 0w-40's contain some percentage of PAO and Mobil uses it in varying quantities in many, if not most of their lubricants that you can indeed pick up at your local parts store.

There are plenty of readily available synthetic oils that indeed use PAO and are sold under the "vollsynthetisches" designation in Germany, such as the Ravenol shown in my signature. AMSOIL also still uses PAO in their Signature Series line and Redline white bottle lubes are majority PAO.
The oil companies then had a premium product that cost marginally more than the standard product but because of the hype around it could be sold for 3 times the price of regular oil and pushed it hard by extolling its better properties, most of which was almost true but none of it of any real benefit for any engine not specifically designed to run it .
So you can run it for 3 times as long as you can run standard oil before it oxadises and starts to brake down chemically.
But that is not why you change your oil
You change it to remove the acid byproducts of combustion which happen regardless of the oil used and more importantly to remove the ultra fine particulates that errode your engine the exact same was as the Colorado river has erroded the Grand Canyon , but they fail to tell you that.
Oils are of course designed to neutralize acids and hold these byproducts in suspension. Oils that are designed for extended drain intervals have improvements made to these characteristics so indeed can be run considerably longer without risk of those contaminants falling out of suspension. Oil filters remove the particulate.
As for mower engine what can I say?
Probably once or twice a year an old worn out 2.5Hp side valve B & S powered mower comes into the shop with about 1/3 of the original oil still in the crankcase burned to the consistency of triple cream on a mower that the owner has had since the 80's and never so much as checked to oil let alone change it or even top it up.

And I would imagine every tech on here would have the same thing happen to them every year
Your 1981 B & S engine will run happily of full splash lubrication and there is a good chance it was actually full splash .
So your use of it just goes to show your absolute failure of understanding of the fundamentals of lubrication inside an engine.
Not sure who he is responding to here but these tangential anecdotes are not at all germane to his earlier rants. That B&S engines are durable and wildly tolerant of abuse has nothing to do with that. And in terms of failure of understanding of the fundamentals, well.... we've been over that.
The tug-o-war between adheason, coheasion & gravity let alone the significance of valence inbalance at the terminals of the molecules, and the difference the shape of them makes to the flow of the oil through the galleries.
I'm definitely no quantum physics prof, but this is essentially word salad designed to hand wave away the fact that he doesn't understand pressurized lubrication or how a positive displacement oil pump operates. Bringing up quantum mechanics by mentioning valance imbalance (something to be discussed with reference to say manganites in terms of anode/cathode development for batteries for example, @JHZR2 is significantly better versed to speak on this bit than I am) isn't relevant here, neither is gravity or adhesion.

The polar nature of certain base oil molecules and additives is predominantly relevant with respect to non-pressure lubricated surfaces like cylinder walls, cam lobes...etc. Where you want to promote the maintenance of a film. This is particularly relevant to engines that sit for significant periods. Esters are quite polar and do a good job in this department, while PAO is not. Group I is also quite polar, but also has poor oxidation stability, amongst other detractors. Polar bases also have good solvency, which is why POE or lower group bases are blended with PAO to properly integrate the additive package.
And FWIW the only calculations in OLDS are just barely high school level and mainly about temperature flow & heat removal .
Get yourself a copy & read it then if you have understood what was written you will have just enough information to work out weather you are being fed fact, fiction or hype.
As an old text book it is probably everywhere used for $ 5 rather than the $ 50 I had to pay when it was a brand new publication.

Over the years I have found oil to be like religion and those who most strongly argue about it do so from a position of blind faith.
Yet he wrote a novel arguing about it... I wonder if he is aware that this observation is, contextually, just introspection?
On one of the motorcycle forums we ran a survey to see just how much the members understood about oil
The question was
Do multigrade oils get thicker as they get hotter. yes / no
Over 90% got it wrong .
I wonder which way he thinks it works? Judging from his remarks on synthetic "flowing too freely" I'm inclined to think that he may be in the wrong camp.
In my TAFE classe I used to ask the question
What is the purpose of the detergent molecules in oil ?
In the 11 years I taught not s single student got the question correct
We put the same question in the final exam and agin just about every student got it wrong
They all correctly described the mechanism of how they work but the students could not get the "detergents clean" BS out of their heads that the advertising companies had implanted .
And if you are wondering.
The function of the detergent is to carry away the particulates that they encounter & prevent them from combining
Secondary purpose is to make the contaminants close to the SG of the base oil so they will circulate freely within the oil to facilitate mechanical removal .
You will find that in OLDS as well no maths required."
Detergents are designed to keep particulate in suspension, this includes broken VII polymers, oxidation byproducts, combustion byproducts...etc. Dispersants are designed to prevent agglomeration, which would result in those products falling out of suspension.

While it is generally true that detergents are not designed to clean-up existing deposits, lubricants have been in fact advertised as being able to achieve that, which would be a function of the detergent and dispersant blend even if only by proxy, as if varnish or sludge is broken down and drawn into suspension via a mechanism such as the inclusion of an ester that does in fact clean, the role of those additives are to keep that in suspension, allowing larger particles to be captured by the oil filter.

A good example of this is my own series of runs with Mobil 1 in our Expedition, as well as @wwillson recent experience with the HPL lubricant products where he saw significant carbonaceous build-up in his filter as the result of this process.

@MolaKule can of course expound on this further.
 
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Let's not forget the if you are going from conventional oil to synthetic you must first run semi synthetic then if no leaks or oil usage you then can run synthetic. However be careful cause synthetic oil will damage seals after use of conventional oil.

You can't use synthetic oil if you used conventional oil for the early part of engine life.

Must flush engine first before you use synthetic.

Do not use 0w in Louisiana as a 10w will protect better in heat.

These are a few misconceptions I heard working at dealership.
 
No they aren't. Engines but be tolerant of a wide range of viscosities because of the impact ambient temperature has on it. This is the largest single factor in impacting what viscosity the engine sees when it is started.

Wrong.

Pressure is the artifact of resistance to flow. We see pressure on the gauge because the positive displacement pump is attempting to cram a specific volume of oil through the system. The heavier that oil is, the more difficult this is, so the artifact is increased pressure. The amount of pressure required reduces as the oil thins with heat, which is why hot oil pressure is lower from cold oil pressure.

When the oil is extremely thick, this can result in the pump going into bypass, which means some of that volume is shunted back to the feed-side and not forced through the engine.

Oil feed orifices are designed to bleed-off the necessary volume from the main gallery(ies) to feed their branches. So for example, on a pushrod engine, the feeds to the branches that feed the lifters and pressurize/lubricate the lifter bores are sized for that purposes are considerably smaller than the main gallery itself.

Oil is pumped, so "flow" is not important. Oils pumps are positive displacement, which means that each turn of the gears displaces a specific amount of oil. How that oil flows under gravity is irrelevant to that function as long as the oil can make its way up the pick-up. In a "sling" situation (small B&S engine) pump bypass doesn't even come into play because there isn't one.

No, the numbers on the bottle tell us two things:

1. The number in front of the W (Winter rating) of the lubricant is the ability for the oil to:
a. Make its way up the pick-up tube; be pumpable. This is MRV
b. Have a minimal impact on the cranking speed of the engine. This is CCS

2. The number after the W is representative of the "hot viscosity" of the oil and is measured at 100C. Each grade has a range assigned to it.

How the oil will "drain back down the drain holes" isn't factored into this scenario. The 100C figure is used to determine the amount of "cushion" in hydrodynamic situations, HTHS tells you that visc under higher temperature, and high shear, and the other figure, the Winter rating, tells you whether the oil is appropriate for the prevailing ambient conditions/starting temperature.

That makes zero sense. The oil pump doesn't know, or care, whether the oil is conventional or synthetic, as long as it can pump it, it will. Since an oil pump, not on the relief, displaces the same volume of oil per revolution, even the viscosity is mostly irrelevant here. While a lower viscosity oil will increase bearing side-leakage an engine would need to be completely destroyed; bearing clearances would have to be past "toss a rod through the side" and you'd have no oil pressure in the scenario he's trying to conjure up.

Viscosity is viscosity and doesn't depend on whether the oil is conventional or synthetic as well. A 5w-30 synthetic behaves the same as a 5w-30 conventional.

Again, wildly incorrect. A synthetic and conventional oil of the same viscosity flow the same, and the engine would have to be well beyond the ability to run for clearances to be large enough to allow all of the oil volume to escape. Of course the artifact of that would be no oil pressure. Engines aren't designed around conventional or synthetic or even a particularly viscosity, but they may have a certain hot viscosity in mind as part of the bearing design. For example, an engine designed to run on 0w-16, 0w-12 or 0w-8 will have wider bearings because of the greatly reduced HTHS viscosity of the lubricant. Because of the reduced load carrying capacity of the lubricant, the bearing area must be increased to prevent metal-to-metal contact.

And yet here you have Ford that spec'd both 5w-20 and 5w-50 for the same engine, lol. Engines are incredibly tolerant (necessarily so, due to the impact temperature has on viscosity, as outlined earlier) of a wide range of viscosities and as long as you don't use an oil with an inappropriate Winter rating (a 20w-50 when it's -25C vs a 5w-50) and don't go thinner than the allowable range (don't run a 0w-12 in an xW-20 application) the engine isn't going to care.

A red herring, strawman and generous hyperbole all wrapped into one here, oh my! No response warranted for this detour.

Gross generalizations and wild speculation, not worth addressing, it isn't even clear what he's addressing here.

It would have had nothing to do with the oil being synthetic or not and would be due to the oils having friction modifiers in them (which energy conserving oils do). Motorcycle oils are not friction modified, the reason of course is shared sumps. There are plenty of full synthetic motorcycle oils that are wholly appropriate.

Again, synthetics are not "freer flowing". While they often have a better Winter rating, this has nothing to do with operating viscosity. Not understanding the subject and then trotting out what amounts to urban legend isn't helping here. Using an oil not designed for motorcycle and shared sump applications can be problematic, but whether that lubricant is conventional or synthetic is wholly irrelevant.

And yet here we have somebody who clearly doesn't understand the basics 🤷‍♂️

Given the above observation, that's quite an ironic statement.

And yet he still doesn't understand viscosity. Clearly, this was money wasted if that's what was supposed to be learned.

But he said it will flow "too good" and explode, what's this pedal back? Now it's just going to cost more money?

Nope, they were developed for cold weather (arctic) and jet engine use, as conventional oils wouldn't hold up in turbine applications, oxidizing rapidly and breaking down. The Germans also developed the Fischer-Tropsch process during WWII, employing coal gasification to produce both fuel and lubricants because they were resource constrained. This process is now employed by Shell to produce their GTL synthetic base stocks and various other products from methane.

AMSOIL was started by a pilot who saw the superior characteristics of the synthetic lubricants developed for turbines and worked with Hatco to develop the first API-approved synthetic lubricant for automotive applications. This was followed by Mobil (Mobil 1) whose history of developing arctic and jet turbine oils using synthetic base stocks resulted in them using that knowledge to develop one for automotive use.


Oil plays a tremendously important role in cooling an air cooled engine, as you don't have any coolant, so the only thing taking heat away from parts is the oil.

Not sure what F1 has to do with this, it is far from the only racing venue to employ synthetic lubricants, they are used universally in everything from drag racing to 24hr races, Nascar....etc.

Wow, this guy should write fiction, he's much better at it than giving oil advice.

Synthetic oils were a far cry from "exotic" once Mobil 1 and AMSOIL became available. The ability to improve conventional base oil quality (Group II) and improvements to PPD's and VII polymers was a natural evolution of lubricants and in no way depended on synthetics. Synthetic oils didn't see any form of wide adoption until the long life approvals were developed in Europe and they worked to extend drain intervals, which necessitated the use of PAO to hold up.

GM developed a "Corvette" spec, which was carried by Mobil 1, and GM and Mobil had a development partnership that benefited both parties.

Semi-synthetics were borne of the philosophy of providing some of the advantages PAO-based synthetic offered (better low temperature performance, greater oxidation resistance...etc) while keeping the cost down. Ergo, some synthetic base stocks were blended in with conventional base stocks which improved the overall performance. There's nothing BS about the name.

He seems to be wildly confused on the different base oil tiers and how that applies to oil labeling.

Group I is the lowest (solvent refined) base oil. Introduce hydrocracking and hydroprocessing and you get a purer end product with lower wax, which in turn has better cold temp performance and oxidation resistance, this is Group II. Refinements to this process have resulted in Group II+, which is an unofficial designation. Severe hydrotreating results in a very pure base oil with a higher VI and even better oxidation resistance and low temperature performance, this is Group III and is considered synthetic in most parts of the world that aren't Germany.

A semi-synthetic can be mixed with Group III, PAO, POE or AN's or a combination of those products. There is nothing that dictates how it is blended.

Modern synthetic oils of course are a blend of multiple bases, the slate for which includes:
1. Group III
2. GTL
3. PAO
4. POE
5. AN's

Mobil products are typically a blend of the bottom 4, while Shell synthetic oils typically use #2, there are still lubricants where they appear to use their Group III base (XHVI) oils. Even though GTL technically falls under the Group III category, it's performance is slotted between your typical Group III and PAO.

I assume he's trying to refer to PAO, which is produced using ethylene gas. This is still something that comes out of the distillation tree, but the production of the building blocks to produce PAO through this process means it has absolutely no slack wax in it and thus has extremely good cold temperature performance and oxidation resistance. These base oils have high natural VI's, which means less VII polymer is needed.

Mobil 1 EP 0w-20 is a predominantly PAO-based lubricant. Most commercial 0w-40's contain some percentage of PAO and Mobil uses it in varying quantities in many, if not most of their lubricants that you can indeed pick up at your local parts store.

There are plenty of readily available synthetic oils that indeed use PAO and are sold under the "vollsynthetisches" designation in Germany, such as the Ravenol shown in my signature. AMSOIL also still uses PAO in their Signature Series line and Redline white bottle lubes are majority PAO.

Oils are of course designed to neutralize acids and hold these byproducts in suspension. Oils that are designed for extended drain intervals have improvements made to these characteristics so indeed can be run considerably longer without risk of those contaminants falling out of suspension. Oil filters remove the particulate.

Not sure who he is responding to here but these tangential anecdotes are not at all germane to his earlier rants. That B&S engines are durable and wildly tolerant of abuse has nothing to do with that. And in terms of failure of understanding of the fundamentals, well.... we've been over that.

I'm definitely no quantum physics prof, but this is essentially word salad designed to hand wave away the fact that he doesn't understand pressurized lubrication or how a positive displacement oil pump operates. Bringing up quantum mechanics by mentioning valance imbalance (something to be discussed with reference to say manganites in terms of anode/cathode development for batteries for example, @JHZR2 is significantly better versed to speak on this bit than I am) isn't relevant here, neither is gravity or adhesion.

The polar nature of certain base oil molecules and additives is predominantly relevant with respect to non-pressure lubricated surfaces like cylinder walls, cam lobes...etc. Where you want to promote the maintenance of a film. This is particularly relevant to engines that sit for significant periods. Esters are quite polar and do a good job in this department, while PAO is not. Group I is also quite polar, but also has poor oxidation stability, amongst other detractors. Polar bases also have good solvency, which is why POE or lower group bases are blended with PAO to properly integrate the additive package.

Yet he wrote a novel arguing about it... I wonder if he is aware that this observation is, contextually, just introspection?

I wonder which way he thinks it works? Judging from his remarks on synthetic "flowing too freely" I'm inclined to think that he may be in the wrong camp.

Detergents are designed to keep particulate in suspension, this includes broken VII polymers, oxidation byproducts, combustion byproducts...etc. Dispersants are designed to prevent agglomeration, which would result in those products falling out of suspension.

While it is generally true that detergents are not designed to clean-up existing deposits, lubricants have been in fact advertised as being able to achieve that, which would be a function of the detergent and dispersant blend even if only by proxy, as if varnish or sludge is broken down and drawn into suspension via a mechanism such as the inclusion of an ester that does in fact clean, the role of those additives are to keep that in suspension, allowing larger particles to be captured by the oil filter.

A good example of this is my own series of runs with Mobil 1 in our Expedition, as well as @wwillson recent experience with the HPL lubricant products where he saw significant carbonaceous build-up in his filter as the result of this process.

@MolaKule can of course expound on this further.
Thanks a lot for such a thorough post. This is what I was really hoping for. It took a lot of years of casual browsing on here to pick up on this stuff. I'm still no expert but I believe I have the basics.
 
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