cheap compressor lubricants (what oil do you use and why?)

OK, so Yong Heng (and I assume the other cheap compressors) recommend an ISO 100 compressor oil. ISO 100 is equivalent to straight 30 weight oil.

I've seen some swear by Royal Purple Synthetic, and some use 30 weight non-detergent, and everything in between. Some compressors last a long time and some don't.

What's everyone's experience here? Do you really need to spend $20 a quart for Royal Purple, or would 5/30 Mobile 1 do the job? Why wouldn't you use a detergent oil?

I realize I'm opening up a lot of opinions here, but I'm interested in understanding what oils would do the job.

Thoughts??
 
Yong Heng actually 'recommends' iso 46, but, that is not a good idea to use in compressors like these.
Those in the know will recommend and only use 100 [And the Royal Purple version is a fantastic option]

That is what I use in my Yong Heng compressor.
Especially since I know how good the RP lubricates, and the fact that inside of the YH compressor, 
the connecting rod joins the crank with no bearing. So that said, there is constant metal on metal friction..
With something like that, RP was the Only choice for me. I wouldn't risk using anything else..

With compressors - "Compressor Specific Oil" is also the best way to go.

I've owned/operated custom shops and used countless compressors in the past..
Some large shop compressors - for pneumatic tools / auto paining, and other smaller compressors - for airbrushing, etc.
I've always used RP comp oils in those, and never had a single issue with any of them.

Just my $0.02, and 1st hand knowledge over a 20 year span.

Sam -
 
I have been using ISO46 only because I have it at work, but since my compressor went down I am going to change to synthetic oil, probably RP. I change my oil when it starts looking dirty, about every 3 hours run time or so. I haven't shopped locally for RP yet but will be doing so. One more thing I will be doing is keeping a log handy of run and fill times etc. I didn't worry about it before but it is nice to know where you stand.
 
When my YH Clone arrived, I clean it up and put Home Depot Synthetic Compressor oil in it, allowed it to run without a load for a few minutes, watching the temps climb. Turned it off and allowed it to cool, did that a couple times. Then I started filling my guns and tanks, I have less than an hour on it. I also put a small magnet in the bottom to collect any metal debris that I'll check during oil changes. I don't think I'll be changing the oil once it gets dirty as I'm not sure color is the driver on bad oil.

Smitty 
 
I have been a mechanic for many years and threw they years I have tested all oils from conventional and synthetic oils for lubricity and breakdown , and have done extensive oil samples to ee what protects things best and yes synthetic is much better then regular oil , I had done a study of RP.,Moblil 1 , AMS,and other brands all work well , but I have found AMS Oil to be just a few notches better , BUT I like synthetic oil best for compressors as these units do get pretty hot and hold not much oil so you want best qualities so weather any synthetic oil or synthetic compressor oil is best , also , Once it is switched over to synthetic , I replace it at 1 yr intervals only because of moisture in my shop .But the oil is still honey color after 1 yr a I seem to average about 10 hours a year on my compressor .

I use AMS OIL in my AirMax 4500
 
As far as finding Royal Purple comp oil 'locally', NAPA auto parts stores should have it in stock.
Make sure to call ahead of time to double-check. My local NAPA didn't have any in, so, I had them grab some from another store.
They'll deliver store-to-store for free, and it usually takes from between a few hours and 1 day. A qt of RP 100 is about $20.00

https://www.napaonline.com/en/p/RNJ01513

If you call NAPA, give them the part number, so they'll know Exactly what you're after: Part #: RPO 01513

Sam - 
 
fishingjim66,

***Distilled Water*** That is also great advise!

At the place I'm at right now, the water is very hard [lots of mineral particles]
I used the tap water in a 5-gal bucket, but, when I dumped it, I saw a mineral ring around the inside..
Long term, that would be an issue, so, for others . . That's another great maintenance tip.

Sam -

PS: I also fill two 2 ltr soda bottles, freeze them, and dunk them in the water bucket when the comp is running.
That also does a nice job of helping keep the temps down. Not always necessary, but, advised for longer run-times.
 
Another Amsoil fan here. Never ever used synthetic oil in my diesel trucks, but for my hatsan Lightning compressor I splurged and bought Amsoil ISO 100 SAE 30/40 right straight from Amsoils website for $14/quart. The temps on my compressor in topping off my tank from 3,200 psi to 4,500 psi haven’t gone past 165 degrees in the 20 minutes it takes. That’s during the summer. My last top off was this last December, and temp only rose to the 140’s.

I bought two quarts, and my compressor takes 14 ounces approximately, so, I’ve got enough for a couple of years of oil changes.
 
In a conversation with Air Venturi I was told Kobolt (Lowes) compressor oil comes from the same vat as the Air Venturi compressor oil. And, it is half the price. Also, distilled water will pull aluminum atoms from the metal. So, I used 1/4th antifreeze with the distilled water to prevent it from happening. Many engine blocks are made from aluminum these days so the antifreeze has stuff like alumaguard in it.
 
I was going to throw this data into some sort of spreadsheet before post it, 
but, since we're all sharing info, i might as well post the pic I have. =D 

I used my Yong Heng comp. [RP lube, 5 gal tap water w/ one 2-ltr bottle of ice]
I needed to fill a brand new / empty 88 cubic ft carbon fiber tank to 4500+psi.

Here's the data that I ended up with.
It'll show the start/stop time, the comp temp, and the tank pressure.

Blue shop cloth, then left yellow paper then right yellow paper. haha

1546708170_18036453475c30e4cadebd32.01797411_Yong Heng Data.jpg




I converted the thermometer on my comp to F, 
and didn't get the chance to convert back to C for everyone with the OEM C display.

Sam -

 
I have done many oil changes in my AV compressor. I started with the Lowes brand Kobalt to break it in a few hours and switched to Kobalt synthetic. Then after a few more changes i noticed a slight increase in the temp of the compressor. Someone on here recommended the Royal Purple synthetic. The stuff works great and the unit runs a bit cooler also. So unless someone finds something better I am sticking with it. They also sell it on amazon and with free shipping it is a win win.
 
What's everyone's experience here? Do you really need to spend $20 a quart for Royal Purple, or would 5/30 Mobile 1 do the job? Why wouldn't you use a detergent oil?
Thoughts??

Amsoil iso 100 compressor oil would be my first choice.

Detergent oils (most automotive) are for applications with an oil pump and filter. By suspending debris in the oil they can cause accelerated bearing wear in these pumps.
 
Tar Pits - I've unfortunately seen garbage like that.

What I find interesting is that for this little compressor, with all the cheapness built in, the best thing you can do is use the best lubricants possible to give it the best chance of a decent life. A bit later this spring, I'll probably spring for a Yong Heng, or clone and use either the Amsoil or RP in the crankcase. Really appreciate all the information - that's what I like about this forum, people share.
 
Detergent additives in oils help prevent the oil from gunking up..
It not used, after a long enough amount of time, the inside of the case could resemble the La Brea Tar Pits. 😁


The purpose dispersants in detergent oil is to suspend particles so the filter can remove them. Non-detergent oil is for engines with no filter and allows particles such as carbon and metal to fall out of the oil so they don't reach bearings.

Back in the day before modern engines you would have to decoke an engine at regular intervals so that the asphalt precipitating from non-detergent oil didn't completely plug the oil returns and block the drain.

Additives in detergent oils will fail if the oil is run for too long or overheated. The coolest running parts in an engine will gather asphalt the fastest.