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There is no misinformation in what I said. If you have a point to contest be specific and we can discuss. If your used oil is not dirty and black your oil is a problem, or you are changing it at 1000 miles or something.
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James all I was saying was that group III & IV synthetics have very poor natural cleaning ability. In fact their solvency for sludge and additives is lower than group I & II. Synthetics only cope with this problem by using a good additive pack that overcomes this negative aspect of the group III & IV's. And that depends on the blender. Some may not choose well. I realize this seems to be a big surprise for many BITOG contributors, but it is the truth.
Ron, yes unfortunately, there is a good bit of misinformation in some of what you post. One trend you exhibit is to focus narrowly (dare I say obsessively) one just one feature of an oil (or certain group or class of oils) to the exclusion of the dezens, if not hundreds of others features or qualities; and then, based upon your focus on one narrow characteristic, you make broad-brush declarations about the oils in question. With respect to this thread, solvency and color (in use) are prime examples. These are but two of the observable characteristics of a motor oil, among the very many characteristics that all bear upon the user's ultimate result, good, bad or indifferent.
Take, for example, this statement you made earlier in this thread:
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I would just look for black dirty oil, and change it at 3K conventional and 5K max synthetic. If it is not black and dirty then you have the wrong oil. And keep in mind that there is nothing magic about synthetics. They have low solvency and need a lot of help to prevent sludge formation.
First, as correctly pointed out by another member earlier, color is not reliable indicator of oil quality or performance (diesels turn oil black almost immediately). You also totally overlook the possibility that you might just have a clean running engine. For example, a few years back, I was driving, of all things, a V-6 Camry, with the arguably infamous 1MZ V-6. During the wty, it developed a slight seeping oil leak around the front valve/head cover. I wandered back to the service bay to have a look for myself, and saw it with the cover off – all you could see was two shiny clean camshafts, their associated hardware, and a large expanse of clean, bare aluminum underneath. This, btw, was late in a fill of Mobil-1 (in fact, they changed to a new fill of M1 after doing the repair.
The oil in this engine, which had been M1 from after the first ~1500 miles or so, always stayed very clean looking. It darkened just a tad, but always stayed completely transparent. AND on top of that, the engine was squeaky clean inside. Well, how do you account for that? I think I had exactly the correct oil for that engine.
Solubility? Well, I’m pretty well convinced by the mass survival of engines being fed synthetic oils, that this is a non-issue as to finished lubes, regardless of base origin, used anywhere remotely near a reasonable interval for the product at issue. I’ve tried a couple long-ish OCIs and seen others go far longer (data in our own UOA section). You certainly are correct about solubility in a general and theoretical sense, but experience has proven that in reality, the inherent solubility of a base oil fades into relative insignificance when you consider finished lube products as they are actually used in the real world. By making solubility into a bigger issue than it really is, you are spreading mis-information. Same for color.
Finally, if you want to see an oil that "needs a lot of help to prevent sludge formation", I'd go with a nice solvent refined, Group-I.
