quote:No, it's not myth, though most synthetics DO have some VI improvers, just not nearly as much as conventional oils. It's the inherently HIGH VI of the PAO and/or esters (and Group III, if it's a wax isomerate) that obviates the need for much VI improver in synthetics. FWIW and IMO, a finished PCMO that had 30% VI improvers would be essentially useless as an engine lubricant. Its operational life would be considerably less than 3000 miles.
Originally posted by userfriendly: Is it just a myth that synthetic engine oils have no VI improvers? If light viscosity base oils are cheaper to produce than heavier oils, a VI improved light weight synthetic would satisfy the product description. Could for example a 10W30 "synthetic" engine oil be blended from the following? 40% group III or PAO ISO 10 base lube, 30% VII, 30% 10w group I/additive carrier package That could be called a TRY-SYNTHETIC
quote:Where are you coming up with this stuff from? "Bright stock" isn't used to classify any Group IV or Group V base oil. And I don't know of even a Group I based oil that has 15% VI improvers. I think you need to do a litte bit more research on how PCMOs are "built" before you start trying to build 'em from scratch on paper.
Originally posted by userfriendly: Ok, lets change that 30% figure to 15% bright stock and 15% VI improver.
quote:Well, "us" doesn't need enlightening. You, however, can find all the info you need by reading many of the posts that are already on this forum. As an example, MolaKule posted in this very thread the percentages of VI improvers used in conventional oils, and they are nowhere near your hypothetical numbers. Take the time to dig around on this forum and read. There is a lot to learn here.
Originally posted by userfriendly: Please enlighten us.
quote:Sorry User. Maybe this will help. POA's and olefin copolymers (OCP's) are both synthesized hydrocarbon molecules, but olefin copolymers is the term most often applied to the fluids used to make oil thickeners and tackifiers. Some flavors of OCP's can be used as base oils. PAO's start with a refinery gas using a process called "catalytic oligomerization of linear alpha-olefins" having six or more (usually 10) carbon atoms. Oligomerization is the "polymerization to low-molecular-weight products" to design a set of smaller molecules that perform as planned. Further molecule linking with hydrogen gas results in a more stable molecule, a process called "hydrogenation." PAO's then are "hydrogenated oligomers of 1-alkenes" in general terms. The viscosity of the final PAO fluid is a result of the type of catalyst used in the process. A catalyst is a material (a metal with a highly ractive gas), such as Boron tri-Flouride (2-10 cSt), aluminum tri-chloride (14 to 25 cSt) and others that accelerates or helps to change a molecule. Intermediate viscosites are made by blending the low viscosity PAO's with PAO's of higher viscosity, such as 40 AND 100 cSt products. [ September 06, 2003, 12:00 PM: Message edited by: MolaKule ]
Still not enlightened I've read thread after thread of people discussing the topic of what by defination constitutes a synthetic material. Now here I have a couple of guys that are saying on one hand, that poly alfa olefins are a synthetic, but olefin copolymers are not synthetic.
quote:I respect your point of view, and I may be just un-aware, but I was under the impression that MOROR OIL, the low quality stuff we find... IS made of BRIGHTSTOCK. Are they not a BASE stock oils (brightstocks)? I do believe that they still make engine oil out of bright stock. If regular oils are not what is, or perhaps the question should be What are the most common base stocks for I or II's? Wouldn't all I,II,III have to start from the same base stock? IS a Neutral base oil made from brightstock or a different animal?
Originally posted by MolaKule: ---snip-- Brightstocks are mostly used in mineral oil gear lubes and greases. --snip--
quote:"Brightstock" is a solvent extracted Group I base oil. I think you are confusing feedstock with "base oils." The feedstock for Group I and Group II is the VGO (vacuum gas oil), which is a product of distilling raw crude. Group III can also have VGO as its feedstock, but some Group III base oils use wax as the feedstock (either slack wax derived during the solvent extraction of Group I production, or waxy raffinate). These Group IIIs are known as "wax isomerates" and they are the Group IIIs that come the closest to matching PAO as far as VI, pour point, oxidation stability, and volatility.
Originally posted by Robbie Alexander:quote:I respect your point of view, and I may be just un-aware, but I was under the impression that MOROR OIL, the low quality stuff we find... IS made of BRIGHTSTOCK. Are they not a BASE stock oils (brightstocks)? I do believe that they still make engine oil out of bright stock. If regular oils are not what is, or perhaps the question should be What are the most common base stocks for I or II's? Wouldn't all I,II,III have to start from the same base stock? IS a Neutral base oil made from brightstock or a different animal?
Originally posted by MolaKule: ---snip-- Brightstocks are mostly used in mineral oil gear lubes and greases. --snip--