Does conventional/semi Oil do anything better than full Synthetic?

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I actually prefer a blend of mineral based and synthetic base oils. Some additives mix with different base oils better than others. You get some of the benefits of each. I have used Motorcraft semi synthetic 5W20 in Lamborghini and Ferrari as well as high powered Bentley and other engines for years. Analysis of the oils has shown normal or even low normal wear patterns.

ali
 
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If any benefit it would likely be due to changing more frequently (so anything like minor head gasket leak or fuel dilution gets flushed out more often), the theory of solvency for additives is a wash because the blender already factor in what to use to dissolve the additives they uses.
 
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The Tin Man feels much more limber after using conventional oil from Australia. Then again, Oz never did give nothing to the Tin Man that he didn't already have.
 
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I've read that one of synthetic oils' advantages was that oil tended to cling better than conventional dino. I feel that synthetic flows better in cold weather and can withstand breakdown to higher temps.
 
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Conventional oils are better at breaking in a new engine. It has more friction than synthetics and can help seat the rings faster.
 
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Conventional oils are better at breaking in a new engine. It has more friction than synthetics and can help seat the rings faster.
It's dependent on the base oil composition and the amount or type of friction modifiers present in the oil. Back in the day when synthetics were majority PAO the statement was generally more true but not so today with typical Group III based synthetics and highly additized conventionals. A Group III synthetic oil has the same basic chemical composition as a conventional.
 

dnewton3

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I am not a chemist, but as it's been explained to me by some very brainy cats here, the following is true:

Presuming the OP means conventional = grp II or II+, and "full synthetic" means grp IV (PAOs) ...
Yes, there is something that conventional oils do better than "full syns", believe it or not.

PAOs are not nearly at good at keeping additives in suspension; Grp II and II+ and III are much better at doing so. In fact, it is very common to see a hint of conventional oil mixed in with a "pure" PAO, so that it can carry the additives. There's no such thing as a "pure synthetic" (most commonly thought of as PAOs), because if it were "pure" there'd be lower base stock to carry the additives.

Now, if you are willing to accept that Grp III is a "full synthetic" (which many are not), then the conversation turns a bit because Grp III syns can carry their own additives well.
 
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I am not a chemist, but as it's been explained to me by some very brainy cats here, the following is true:

Presuming the OP means conventional = grp II or II+, and "full synthetic" means grp IV (PAOs) ...
Yes, there is something that conventional oils do better than "full syns", believe it or not.

PAOs are not nearly at good at keeping additives in suspension; Grp II and II+ and III are much better at doing so. In fact, it is very common to see a hint of conventional oil mixed in with a "pure" PAO, so that it can carry the additives. There's no such thing as a "pure synthetic" (most commonly thought of as PAOs), because if it were "pure" there'd be lower base stock to carry the additives.

Now, if you are willing to accept that Grp III is a "full synthetic" (which many are not), then the conversation turns a bit because Grp III syns can carry their own additives well.
Mobil also discovered early that all PAO didn't play well with oil seals of the day.
 
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