ISO 68 POE ESTER AC Compressor oil as Additive?

[ARCOgraphite]

I see this stuff when I'm at NAPA. I read the bottle and its says 100% POE Ester lubricant. I had been able to find VOA of this stuff in the past but cant seem to locate any that show additives - if any. When I did a general search I did see you can get pure PAO also in ISO 68 (20 weight) and ISO 100 (30 weight). Without any experience in using this it seems the ISO 68 could be the poor mans "micro lubricant".

 

[Keith_Stone]

Use only for the intended application. POE compressor oil is highly hydroscopic. IMO as a lube outside its purpose is pointless. It's pretty much raw POE with few additives.

 

[ARCOgraphite]

But can we assume this same POE oil was traditioanlly blended in the classic EoM trisynthetic formula of PAO/AN/POE? I was thinking a maybe pint per sump as an effective polar lube booster. The add pack in the sump oil will control the base number?

 

[dave123]

Sounds like a great idea I go for it if it was you car but I would run a full QT more has to be better.

 

[ARCOgraphite]

I was thinking you KNOW whats in the bottle compared to OTC snake oils - and you will make your own semi-syn blend from your fave conventional oil. I was more worried about additive clash. Dont know if this uses a Ca detergent(OK?) or some app specific lithium compound (not ok for sump). Also would like to see volatility.

 

[Keith_Stone]

Now that one I can't answer. I just don't know. I would however be hard pressed to assume. Are all application POE's backward compatible? HVAC POE's have been known to be rough on seals and gaskets. Especially those not designed for it.
IMO I'd prefer a higher PAO to POE content, like 4:1 as a motor lube but that's an opinion.

 

[Tom NJ]

In order for an ISO 68 POE to be miscible with HFC refrigerants, it must contain a high percentage of branched acids, which lowers the VI and raises the pour point compared to the linear POEs usually used in motor oils. That said, the results are still pretty good, with VIs of 90-120 and pour points around -40F.

These POE AC lubricants contain little to no additives, and have no detergents, dispersants, or ZDDP. Therefore adding them to motor oil will dilute vital additives. I wouldn't exceed 10%, and even then I'm not sure it's worth it.

Personally I would not add it to my motor oil at all unless I could dose it first with a good DI package.

Tom NJ

 

[daman]

This has been discussed here before,no it wont work.

 

[ARCOgraphite]

Thanks Tom - I did see the modest VI and high 40C visc. on one PDS I found and went, Hmmmm ... Now i know. Another drawback, this stuff is not inexpensive but is cheaper than the once popular "micro lubricant". Not for over winter I suppose.

 

[ARCOgraphite]

Discussed, but tried with rigorous UOA and fuel mileage reporting? I might plan the latter. Also as an additive (12-16oz) NOT 100% sump. Also pure PAO are available too.

 

[Tom NJ]

Originally Posted By: ARCOgraphite
But can we assume this same POE oil was traditioanlly blended in the classic EoM trisynthetic formula of PAO/AN/POE?


Not even close. The XOM POE was a linear TMP ester with a Kv40 of 19 cSt (between ISO 15 and 22) and a pour point of -65F. The ISO 68 AC POEs are branched pentaerythritol type esters with Kv40s of about 68 and pour points of about -40F. They are okay for motor oils but not the ideal, and have no additives.

Tom NJ

 

[bullwinkle]

I would think oxidation would also be a problem-refrigeration oil was never intended to be used in the presence of oxygen, moisture, or anything but refrigerant. It sounds risky to me.

 

[JHZR2]

There are tons of different kinds of esters, and those double end capped HVAC ones will bear no resemblance to another ester.

Remember, "ester" only means one kind of functional group in an organic molecule.

I believe MolaKule had some good ester writeups some time back.

 

[Tom NJ]

Originally Posted By: bullwinkle
I would think oxidation would also be a problem-refrigeration oil was never intended to be used in the presence of oxygen, moisture, or anything but refrigerant. It sounds risky to me.


Actually the highly branched PE type POEs are more oxidatively stable than regular POEs because they have fewer methylene hydrogens. They are used in the most advanced jet engine oils and high temperature industrial lubeicants.

For more technical info on esters see: Esters in Synthetic Lubricants

Tom NJ

 

[ARCOgraphite]

Guys, Thanks for the info. I had lightly researched this stuff about 5 years ago but forgot most of it. I didnt get any juice to try today - only went to Advance AP to get some denso PT20TT plugs for ford/mazda waste spark ignition. I Inquired about AC lubricant and they only had PAG ISO 100.

 

[ac_tc]

Use redline engine oil instead as an additive if
you just want to índuce some esters into your oil.

 

[Ken2]

PAG oils are nasty. Dangerous vapors, makes paint bubble, eats certain elastomers. Nasty stuff. I've used in in R134a reefer systems.