Understanding Lubricity in Blended Brands of Oil......

[Idrinkmotoroil]

It has always been my "gut" feeling that conventional group one or two oils had some type of redeeming quality which allows them perform well inside the bowels of our engines. I have always been impressed how some group one and two oils perform pretty decently in comparison to much more expensive synthetics , at least in short term drain intervals. Thus I always thought of blended oils as being the "best of both worlds", thinking that conventional oil has its benefits, as does synthetic oil. I am just talking off the top of my head here, based on my gut feelings, nothing scientific to prove any of my beliefs.

Lately I have been looking at the Schaeffers and Synergyn products (I am in the process of using both of them in my next two oil changes). I noticed that they both talk about the superior lubricity qualities of conventional oil stocks. From their literature it sounds as if they use conventional oils due to their lubricity traits. So the question is, does conventional oil have superior lubricity traits compared to synthetic oil ?. In other words, is there something about group one and two oils that is helpful to the operation of our engines, which you don't quite get with a full synthetic oil ?. I hope I am not confusing things here.

As usual, any opinions welcomed.

 

[pedaltothemetal]

I have my own opinions about the lubricity of dino vs $$$synthetic. In oil analysis it's important to get the TBN to see if there is still life left in if you are doing long drains. Besides that, I believe all other measurements other than the depleting of what was there to start with in the virgin oil anaylis is not accurate. The wear metals from the engine I don't believe to be soluable so what is measure is not all of it. If one were to get an accurate picture, then you have to take apart the engine and gather every metalic particle and then measure them. I have been looking at the testimonials of engine longevity and that's where in my mind determines which oil gives the best wear. I also find wear = friction and friction = temperature. Some testimonials in Redline and Royal Purple convince me that these and others of the "you get what you pay for synthetic group" has something in there that the cheaper oils don't have to prevent wear.

 

[Patman]

quote:

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Originally posted by pedaltothemetal:
I have been looking at the testimonials of engine longevity and that's where in my mind determines which oil gives the best wear.

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Obviously if an engine lasts long using a certain oil and a certain interval, that lets us know what the true story is, but who can wait that long? By the time that particular engine has racked up 200 or 300k, the oil that person used has been reformulated a few times.

We need to figure out NOW, as to what oils work better than others. The best way to do it would obviously be through engine teardown, but who can afford that? And even if you could, why would you bother? Oil analysis may not be 100% perfect (esp. with such varience between labs) but it's still very valid.

And back to the original topic, I believe that each base oil has it's own pros and cons compared to the others, so blending them helps get the best of everything. Sort of like how a lot of synthetics use both PAOs and Esters, since they compliment each other. (when I say blending, I mean by the oil companies, not the home brew stuff individuals get by mixing brands)

 

[MolaKule]

"In other words, is there something about group one and two oils that is helpful to the operation of our engines, which you don't quite get with a full synthetic oil ?. I hope I am not confusing things here. "

There is always compromise and se-sawing to get the best lubricant at the most modest price.

The higher the group (mineral oil) the less the amount of sulfur in the base oil. Sulfur provides a measure of the base oil's lubricity (anti-friction, AW properties) and anti-oxidant capabilities. You lose some of that the higher you go in group number. So you have to make it up in the additves.

PAO's and Esters (full synth's) have natural lubricity based upon their molecular structure. Esters are the most thermally (oxidatively)stable, most anti-friction fluids available. Unfortunately, they cost more than PAO's, so you add just enough Esters to make up for some of the disadvantages of PAO's. The exception is Redline, since they use more PE esters. PE's run approx. $13.00/L for lab grade fluids, so Redline can't sell them cheaply.

So, the lower group mineral fluids have natural lubricity and AW built in because of the high sulfur contents (600-900) ppms.

Since synthetics basically possess no inherent AW properties (but great FM properties), they have to have fairly large values of ZDDP or moderate levels of Moly or other metals to provide that capability.

Formulating with various base oils and additives is both an art and a science.

 

[Idrinkmotoroil]

Molakule, that is a **** helpful reply, thanks very much for that insightful information. Very interesting stuff indeed.