Oils with no VI improvers at all?

[Patman]

I remember when I first got into synthetics, they used to say that most 10w30 synthetics contained no VI improvers at all. Is this still true? What oils and viscosities do you guys know of that contain zero VI improvers?

 

[MolaKule]

I recall some companies CLAIMING that there were no VI's. Now, formulation-wise, this would make sense, because many of these early oils consisted of di-ester bases, with a low-level additive package to mediate seal swell, friction modifiers, dispersans, etc. However, this was before wide spread "man-on-the-street" low-cost oil analysis. Therefore (using my Congressional voice, ah-hem!), I can neither deny nor confirm the above claim.

 

[Dick in Falls Church]

Some years back, AMSOIL made 10W-30 and 15W-40 without any VI improvers. When non-shear (or maybe low shear, or shear resistant) VI improvers became available, they reformulated. Possible that AMSOIL SAE 30 Diesel oil is made without VI improvers, but don't know. And they are a bit tight-lipped about formulations.

 

[frederick]

I have confirmed that Amsoil's SAE 30 contains no VI improvers. I do not know of any others except for maybe Schaeffer's straight weight synthetics, but I do not think they are sold in small quantities. GW

 

[Chris A]

Gosh, I hate to sound like a Royal Purple ad, but I was told that none of their street oils have VI improvers. I don't have the email in front of me right now, but I'll confirm what I state above. If I'm wrong, I'll post it.

 

[MolaKule]

Dick in Falls Church, VA.: "Some years back, AMSOIL made 10W-30 and 15W-40 without any VI improvers. When non-shear (or maybe low shear, or shear resistant) VI improvers became available, they reformulated. Possible that AMSOIL SAE 30 Diesel oil is made without VI improvers, but don't know. And they are a bit tight-lipped about formulations." This was mostly done for economic reasons. It was cheaper to reduce the ester percentages by using a mostly PAO base, changing the ester to TMP polyol, and adding the VI's. It's still good, but not as good as the original formula.

 

[Bror Jace]

I would expect all true straight-weight oils to have ZERO viscosity index improvers in them, dino or synthetic. It’s the multi-vis oils that are known for loading up on Viscosity Index Improver (VII). In general, the wider the spread, the greater the amount of VII needed … assuming all other variables are equal … and they usually are not. But … There’s been something that I’ve been wondering about for some time that some of you tribologists (official or otherwise) might have to answer. Which weight of oil (all other variables being equal) will have more VI? a 5W30 or a 10W40? The first oil has a spread of 25 points (30-5) while the second's is 30. But is it a straight, addition-progression like that? I’ve always figured the RATIO of the base oil to its “hot number” is more important than the subtracted spread. Taking a 5 weight oil and making to a 30 is a six-fold increase while taking a 10 weight oil and making it 40 is only four. See my point? Which methodology is correct and therefore which formulation (in general) uses more VII? As for the original question posed in this thread, I thought most REAL synthetic (Group IV & V base) oils of 10W30 weight had no viscosity index improvers. Conversely, I thought all 5W30 weights, even true synthetics, had some VII in them.

 

[Patman]

I believe that the thicker oils (the first number that is) need less VI improvers, so a 10w40, despite it's 30 point spread, will use less of the VIIs than a 5w30. As well, a 20w50 oil will use even less VIIs than a 10w40 also. A 10w40 definitely needs more VIIs than 10w30s, which is why I don't like that viscosity. [ July 18, 2002, 03:45 PM: Message edited by: Patman ]

 

[con carne]

quote:

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Originally posted by Bror Jace: As for the original question posed in this thread, I thought most REAL synthetic (Group IV & V base) oils of 10W30 weight had no viscosity index improvers. Conversely, I thought all 5W30 weights, even true synthetics, had some VII in them.

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I wish it was true Bror, but I have called many companies (including Redline on their "SAE Racing Oils") and they all told me the same thing - they all use VI improvers. The only one that I have found is Amsoil SAE 30 - they have assured me that there are zero VI improvers in this formulation. They also did say that their 10W30 and 15W40 oils contain the least amount.

 

[sprintman]

MolaKule, I see you say the Amsoil formulation good but not as good as it used to be? Overall how do you think Amsoil and Redline compare with their current formulations?. I personally like Delvac 1 and M1 0W40 but they generally seem to be very much out of favour on this forum (although some real SuperSyn analysis figures might change that).