Urban Legend from decades ago ... synthetic oil was "too slick" for engines

[OVERKILL]

How does this keep getting repeated?!?!

I WAS THERE. In the 80s, switching to Mobil 1, 10w-30 almost instantly wiped out main seals and dumped oil everywhere. I always knew this going in, and always just replaced the main seals when oil started leaking all over the place, after a hundred miles or so. It was the price I expected to pay, to run those older design motors out past 200,000 miles, which was far less commonplace then. Being a lot younger, I didn't mind getting greasy, getting under the car, and replacing seals. Seals were a lot easier to get to in those days too, in fact a lot of cars were designed so the main seals could be replaced in an hour.

But Mobil1 made engines leak, period. Anyone saying anything contrary just goes to show what a heaping pile the internet has become. Dead internet is real, AOL starting endless summer was just the beginning.

Mobil 1, particularly in the tri-syn era, contained both esters and AN's, both of which clean. This was also during an era when the performance standards for engine oils were much lower than they are now.

So, if you had an engine that was run on the conventional swill of the era, it likely contained considerable deposits, which also worked as dams that blocked leaks. Switching to an oil with a base oil blend that dissolved these deposits would very quickly reveal these leaks. This is why just replacing the seal/gasket would resolve the issue and it wouldn't come back, because the issue wasn't in fact caused by the oil, simply revealed by it.

 

[RDY4WAR]

Mechanics are some of the worst to take specific, technical advice from (in general) as they are heavily biased. (often unknowingly so) If all you see is bad things all do, you're going to form wrong conclusions. I call it Echo Chamber Syndrome. Brand X could have no higher or lower fail rate than any other brand, but when that particular brand accounts for 50% of market share, it's going to appear as though they have a higher fail rate if all you're seeing are the bad.

ASE techs aren't taught jack about engine oil except how to change it. Many of them spread the same myths that have been circulating for decades.

 

[Carlostrece]

Mechanics generally know little to nothing about engine oil, just like the guys swapping parts at power plants generally don't know much about the lubricants used in the turbines, it's Engineers that get into that data and analyze it.

Certified mechanics might disagree. Are you an oil engineer? I know an oil company management person who agrees with mechanics.

I know an oil engineer too, but we've never discussed this topic. If I get the chance I'll talk to him about it. However, I don't know how much he knows about cars. The oil engineer I know is part of a team that makes oil, but I don't know if he's ever worked on a car or changed his own oil.

 

[kschachn]

You can have your opinion. I have mine. I know several certified mechanics who say exactly what I said. Possibly you may know others who think differently.

The dealership wasn't going to risk a potential problem that might come back to them. The dealership played it safe. If the customer wanted to experiment by personally changing his oil from conv to syn in a high mileage car, that would be fine because it would be his risk. Switching that old HM car from conv to syn might have worked out fine, or might not. The dealership didn't want to risk it.

I've switched multiple HM cars from conv to syn.

Several old HM cars that I switched started leaking oil, and/or burning oil, and/or had lower oil pressure at idle. Switching those cars back to conv resolved those issues.

A few of the old HM cars I that switched from conv to syn had no problems.

If a person wants to switch an old HM car from conv to syn, then I suggest a HM syn oil to give the best chance for not leaking. My preferred HM syn for that is Quaker State High Mileage Full Syn because it's thicker than other HM syn oils.

My other preference is a HM blend oil such as Maxlife Blend or Quaker State HM (blend). Of the two, QS HM is thicker than Maxlife Blend, but I have had good results with Maxlife Blend. Maxlife Syn leaked like a sieve in that same car.

The thickest HM (blend) that I know of is Pennzoil HM (blend). But I don't need that thick to prevent my car from leaks, and it might be a bit thicker at cold start than I'd want.

So is it thickness? Or slipperiness? Or the method of obtaining the base stock? I can’t figure out.

 

[Hohn]

Let's not forget Dura Lube. The way that stuff was marketed it could fix anything. They practically stopped short of calling if an elixir.

I think I might have even bought some of that "fixir elixir" back in the day.

 

[OVERKILL]

Certified mechanics might disagree.

My best friend is a long time mechanic turned foreman for a bus company, has every Cummins certification under the sun, but, because he has self awareness, knows he knows very little about oil. He often asks me about it, and what we are discussing on here, because I stay on top of the subject more than he does.

Are you an oil engineer?

Nope, just an amateur oil enthusiast who has been told by people that make oils, like Dave at HPL, that it's shocking how much I know about the subject. Same reason I know obscene amounts about nuclear power generation: an insatiable thirst for knowledge and a natural inclination towards engineering subjects.

I believe @RDY4WAR and I are kindred spirits in that regard.

I know an oil company management person who agrees with mechanics.

Agrees in what way, and on what? Is this person a tribologist or formulator, or are they just making financial or business decisions? Was your query directed to him about the difference in additive package structure, and if there is one, between synthetic and conventional oils that could result in the synthetic oil having a lower COF?

I know an oil engineer too, but we've never discussed this topic. If I get the chance I'll talk to him about it. However, I don't know how much he knows about cars. The oil engineer I know is part of a team that makes oil, but I don't know if he's ever worked on a car or changed his own oil.

Well, he would at least be able to talk to you about additive packages and how they function, which sounds like it might be beneficial.

 

[JAG]

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

Chemically, it is interesting to consider the reasons for this measurement while it is recognized that in one case for PAO, the chemistry is entirely made up of highly branched isoparaffins. In the case of Oil B, which contains only Group III as a base oil, we have several different types of compounds present in that base oil such as isoparaffins, naphthenic compounds, cycloaliphatic compounds and others. Even though there are many isomers present for the PAO case, they are all still considered branched isoparaffins whereas there are more than just isoparaffins in the Group III oil. Since the chemical makeup is different for these different base oils; it is also understandable that some of the end properties would likewise be different.

 

[slo town]

My first new car was a 1978 VW Rabbit. Loved it. Quick, took corners like it was on rails, fuel injected, good MPG and was a far sight better than the Pinto/Gremlin/Vega offerings of the era. I eagerly tried Mobil 1 very early on, one-quart metal cans, but my engine couldn't hold oil pressure. The low oil pressure dummy light would constantly flicker at idle, and the idle was set at the right RPM. So perhaps it was "too slick."

I used those same metal can versions of Mobil 1 back then. At the time it only came in a 5W-20. I used it for a few hundred miles in my TR6. At hot idle the oil pressure was be far too low for my comfort. This wasn't because of "slickness", it was because 5W-20 was too thin for the motor. I remember 20W-50 was specified in the owners manual. My oil choice at the time was that green colored Kendall stuff. GT something IIRC.

Scott

 

[spasm3]

I always thought that Mazda recommending against synthetic oil in rotary applications was weird as they claimed it wouldn't burn as clean in the combustion chamber vs a conventional oil. Wouldn't a more refined oil like synthetic burn cleaner if the molecules were more even and more refined?

I seem to remember that this was some problem with synthetic affecting the apex seals in the mazda rotary.

 

[JRay’07]

I seem to remember that this was some problem with synthetic affecting the apex seals in the mazda rotary.

Strange as it sounds, Mazda also offered a synthetic oil made specifically for rotary engines.

 

[Hohn]

My best friend is a long time mechanic turned foreman for a bus company, has every Cummins certification under the sun, but, because he has self awareness, knows he knows very little about oil. He often asks me about it, and what we are discussing on here, because I stay on top of the subject more than he does.

Nope, just an amateur oil enthusiast who has been told by people that make oils, like Dave at HPL, that it's shocking how much I know about the subject. Same reason I know obscene amounts about nuclear power generation: an insatiable thirst for knowledge and a natural inclination towards engineering subjects.

I believe @RDY4WAR and I are kindred spirits in that regard.

Agrees in what way, and on what? Is this person a tribologist or formulator, or are they just making financial or business decisions? Was your query directed to him about the difference in additive package structure, and if there is one, between synthetic and conventional oils that could result in the synthetic oil having a lower COF?

Well, he would at least be able to talk to you about additive packages and how they function, which sounds like it might be beneficial.

I share your autodidactic tendencies. Insane levels of natural curiosity plus living in the information age that allows them to be indulged to a degree never before imaginable is a powerful combination.

My knowledge base in oil is far behind many people in this forum, but I'm trying to close the gap a bit.

 

[Hohn]

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


View attachment 283385

In an LSJr video, he mentions that friction and wear are a tradeoff--- namely, if want lower friction, it may come at the cost of slightly higher wear.

I took note of that because I've always been under the impression that friction WAS wear and vice versa. WHen I have a paradigm shattered, I remember it.

So, is it possible the group III has lower wear rates?

 

[OVERKILL]

In an LSJr video, he mentions that friction and wear are a tradeoff--- namely, if want lower friction, it may come at the cost of slightly higher wear.

I took note of that because I've always been under the impression that friction WAS wear and vice versa. WHen I have a paradigm shattered, I remember it.

So, is it possible the group III has lower wear rates?

I'm not sure if he was speaking to this specific bit, but back when the Honda paper was introduced ages ago, we (@Shannow was active in this discussion) were discussing the Stribeck curve in relationship to what Honda was discussing:

The emphasis with these thinner and thinner oils was to, enabled by special coatings and wider bearings, push more of the operating regime out of hydrodynamic and into mixed, where, despite there being a bit of wear, due to additives and these coatings, friction was lower, which incrementally improved efficiency.

This of course isn't about the base oil, but the different operating regimes where the fluid friction of hydrodynamic and zero wear actually has a higher friction coefficient than stepping into mixed, where the AW and FM additives sloughing, sliding and interacting actually reduces friction.

The information @JAG posted above is also valuable, as it shows that, with the same additive package, an oil formulated with straight PAO or Group III blended with PAO, can slightly improve efficiency (image is from the same link):

But, per my discussions with Dave, you likely wouldn't end up using identical additive chemistries for both a PAO-based oil and a Group III based one. Their (HPL) FM selection and treat rates are tested for each individual product, because different base additive chemistries and different base oil blends respond differently to different FM blends and treats.

 

[Astro14]

Mechanics generally know little to nothing about engine oil, just like the guys swapping parts at power plants generally don't know much about the lubricants used in the turbines, it's Engineers that get into that data and analyze it.

Agreed.

Some of the dumbest things I have ever heard about oil have come from “certified mechanics”.

My personal favorite - “You can’t use that 0W30 oil in your car, it won’t have enough pressure when it’s cold, because it’s a 0W. You need a 10W30 just to give it enough pressure when the engine is cold.”

 

[Astro14]

Certified mechanics might disagree. Are you an oil engineer? I know an oil company management person who agrees with mechanics.

I know an oil engineer too, but we've never discussed this topic. If I get the chance I'll talk to him about it. However, I don't know how much he knows about cars. The oil engineer I know is part of a team that makes oil, but I don't know if he's ever worked on a car or changed his own oil.

Uh, OK, so, now you’re saying that a manager knows more about oil than engineers?

And he is more likely than an engineer to have changed his own oil?

Really?

 

[Mechanician]

This one had some merit but not for the reasons many believed. It wasn't due to it being too "slick" but rather because the additive response was better in group I and II conventional base oils, promoting better ZDDP reactivity at colder temperatures. That's no longer the case as research in group III base oils is showing better additive response than group I and II. Thus, we're starting to see dedicated break-in oils made with group III base oil. You still don't want to use group IV PAO due to the low solubility and group V ester and AN due to competition with ZDDP at high concentrations.

I have a story of a Volkswagen DSM swearing to this, by telling me about a GTI at another shop in his district, in the early 2000s.

They had verified high oil consumption - low miles - no mechanical defects. Customer had changed the oil soon after purchase with some synthetic super oil, and the rings had never seated. He stated that under his direction, they had to remove the pistons, and wipe down the cylinders with solvent. Then refilled with a dino API rated oil for break in - problem was solved. FWIW

ASE techs aren't taught jack about engine oil except how to change it. Many of them spread the same myths that have been circulating for decades.

This is an aspect of so many trades, mentors pass down not only valuable experience, but also some misinformation. And so-on, and so-on.
We were taught to watch the API ratings!
Also to use what comes out of this hose.

 

[kschachn]

I have a story of a Volkswagen DSM swearing to this, by telling me about a GTI at another shop in his district, in the early 2000s.

They had verified high oil consumption - low miles - no mechanical defects. Customer had changed the oil soon after purchase with some synthetic super oil, and the rings had never seated. He stated that under his direction, they had to remove the pistons, and wipe down the cylinders with solvent. Then refilled with a dino API rated oil for break in - problem was solved. FWIW

That owner should have been using a VW 502 00 approved oil, right? I wonder how many fully conventional oils there were that obtained that approval back then?

Why the VW dealer would have used a "dino API rated oil" is a bit of a mystery.

 

[Johnson Johnson]

But they had Slick 50 back then

Absolute BS product that is. Unbelievable they're allowed to sell it.

 

[Mechanician]

That owner should have been using a VW 502 00 approved oil, right? I wonder how many fully conventional oils there were that obtained that approval back then?

Why the VW dealer would have used a "dino API rated oil" is a bit of a mystery.

Again this was a story I heard - FWIW.
The point he was making to me was - that the factory fill was a "break-in" oil, and should have been left in long enough to seat the rings.
He made a point to mention that he didn't want even the "recommended" oil used for the fill, but instead the most basic dino oil that could be found at Wally-world or where ever. Because he thought that would be more like the factory fill.
And as we know "recommended" translates to "Use whatever you want" to many.

 

[kschachn]

Again this was a story I heard - FWIW.
The point he was making to me was - that the factory fill was a "break-in" oil, and should have been left in long enough to seat the rings.
He made a point to mention that he didn't want even the "recommended" oil used for the fill, but instead the most basic dino oil that could be found at Wally-world or where ever. Because he thought that would be more like the factory fill.
And as we know "recommended" translates to "Use whatever you want" to many.

They guy is clueless. VW doesn’t use a special break-in oil, what was in the engine was the same approval as what was in the owner’s manual. And at that time it was a synthetic 502 00 approved oil.

The whole story seems more like a backhanded approach to prove something else. And not a very good one at that.