HOBS & Thermal Stability? Not according to YT Oil Guru🤔

[cadchris]

Can the experts please answer this about HOBS? I just got a reply from that "YouTube Oil Goober Guru Geek" when I left a comment about him not liking HOBS.
His reply: "Bio-derived base stocks tend to not be thermally stable and leave more deposits than traditional synthetic oils."
So does mean that well known leader in HOBS oil isn't thermally stable & leaves deposits, or is their chemistry advanced in some way?
What in the VOA would indicate this?

I'd like to reply to him intelligently & put him on the spot if he's wrong. I may need to reach out to that company & ask them for a scientific response.

 

[Rand]

IMO not worth engaging.. just move on with life.

All HOBS oils are not created equal you could both be right/correct/whatever

 

[JAG]

Here is some discussion. https://bobistheoilguy.com/forums/threads/hobs-base-oils-and-implicit-inherent-fm.365419/

I did high temperature tests of RLI 5W-40 when that oil became popular. I forget most of the details, but something along the lines of separation seemed to have occurred. Another member who used to post here also tested it in a lab and among other things, he reported that “veggie sludge” occurred. Some people on the forum got very upset about these results. Emotional and financial interests in a product tend to cause that reaction.

 

[Tom NJ]

HOBS (High Oleic Base Stocks) are derived from vegetable oils and are glyceryl esters containing a high percentage of oleic acid. Oleic acid has a double bond which is inherently oxidatively unstable. I have seen some data years ago in a slide presentation that HOBS as pure base stocks are less stable than Group I stocks, but I have not verified that statement and the technology may have improved (perhaps someone here has data?).

Such base oils require extra oxidation inhibition (special anti-oxidants) to make them useful, but I believe they are still not as thermally stable as properly inhibited fully saturated hydrocarbons such as Group III or PAO. Alternatively the double bonds can be hydrogenated to improve stability, but then you lose the already marginal low temperature flow properties.

I have seen HOBS recommended for lower temperature applications such in hydraulic oils, grease, or metal working fluids where their high VI, biodegradability, and lubricity are an advantage, and they have found some use in motor oils when well inhibited and blended with other stocks. I would not consider them for highly oxidative applications such as air compressors, oven chains, or jet engines. I have not seen data on deposit tendencies, but given the structure with double bonds and long linear hydrocarbon chains it would not surprise me if they were more deposit prone relative to saturated oils at very high temperatures.

 

[cadchris]

Thanks JAG & Tom for your expert insight. The article that JAG posted is what I've read many times & didn't know what to make of it & so called inherent problems of HOBS in general I read about.

It just has me thinking of not recommending it now for a unique application to a group of hardheaded "by the factory manual" sheeps & lemmings. I should start a dedicated thread for this particular auto group so they can read my concerns about this engine platform I recognized that others never did & so they can read what BITOG Experts have to say & my idea of a possible synergistic concoction added to a good quality high zddp oil that this group has been dedicated too after years of my readings here vs. HOBS RLI.
However at least consider using RLI antimony concentrate or EP #132 based on Molakul's early white paper on antimony & zddp that seems could be a good match in Oil Heaven, especially for this unique, very noisy old engine platform.

If an additive would work, it would be proof to convince this very rigid group to use an advanced fully formulated oil with similar properties to quiet down these noisy old motors.

Rand, you're right, I shouldn't have clicked on his video for any oil education, but was looking for an introductory 101 oil vid to show this group about current oil technology not discussed in a factory manual from 1980........
I think LS is trying to get a tv show on Motor Trend tv, since they fired everyone & discontinued all the good shows like Engine Masters from Westech Performance, Roadkill & Vicegrips Derrick & his antics! All those guys started on YouTube but weren't so smarty pants personalities & were genuine easy going gear heads.
I bet Todd from Project Farm & Lake Speed will show up on MotorTrend tv real soon for their outgoing'ness which I find too hard to watch & like you boldly advised:
"...move on with life....".
Remind you of someone?. I hope he doesn't show up here.

Anyway,
Personally, I'd hope someday Molakule would start doing Masterclasses & Tom too on offdays!
I'd sure Pay-Per-View!