All the different types of air compressors have different specs of Compressor Oil.

And it's Tuff to find out exactly what "compressor oil" IS,and the various specs,,,,such as to be able to Cross-Refference it and use a more common type oil.

Recips---Piston Type compressors such as yours most probably is use what is basically NON-Detergent Engine Oil.

It has a different additive package than actual engine oil,also.

It has a different Oxidation Inhibitor,,,and very Low Ash content.

Reasons are to protect the valves,,,and to prevent carbon deposits.

The NON-detergent deal is this----

Compressors are almost all SPLASH Lubrication.

The Crankshaft Stirs the oil and splatters it around inside the crankcase to deliver the oil to the various parts.

Conventional Motor Oil would be whipped into a Foam very quickly,,which reduces the "Flow Rate/and the Return Rate".

Not enough LIQUID Volume reduces Cooling as well.

Foamy Oil cannot carry away much heat from internal parts.

The Detergents in Engine oil are what Foams---it does OK in Engines,,,because they have a shrouded Sump to collect returned oil,,,and a Pressure Pump to deliver oil "piped" thru passages under pressure,,,where it Cannot foam.

Old Lawn Mower engines' Lube System is identical to Air Compressors---a Splash & Splatter type---and they've insisted on Non-Detergent Oil forever,for exact same reasons.

Non Detergent oil also does NOT suspend Carbon Particles.

It appears to stay "Clean" itself,,,but the bottom of the crancase is filled with Sludge which falls Out of the Oil.

Hi-Detergent Oil DOES suspend carbon---which is why Engine Oil comes out "Black" and Filthy looking,,,but inside of engine is relatively Clean.

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Official Recommendation:

Use actual "Compressor Oil".

It's available at most auto parts & hardware stores & Home Depot type places.

Dayton has it's own oil label.

Part # 1WG49 for Synthetic Oil

Part # 1WG50 for Mineral Oil

"Non-Official"

Any 30 Weight NON-Detergent Motor Oil is fine for air compressors.

That weight is suitable for a wide range of weather temperatures.

In Sub-Zero Climates,,,Try 10 or 20 weight to reduce start-up torque/load on electric motor when cold

In areas with Long,Hot Summers,,and mild winters,,40 weight is good for compressors which get heavy useage /long runtimes.

10's of thousands of air compressors have run 10~15~20+ Years

on plain old 30 weight Non Detergent Motor Oil.

(Probably as many have run fine "forever" on "WRONG" Hi-Detergent Motor Oil.....Nope,,it's Not RIGHT,,,but it IS the Reality.

People do it all the time with no disaster occuring.

Which probably only proves "Oily Shaving Foam" is a better lube than expected.

---I still would NOT use Hi-Detergent oil in any kind of Splash Lubed Motor or Compressor,,,,,why tempt fate??)

Compressors Mfgrs wised-up to Synthetic Oils long time ago.

The superior lubrication and extended run-time/Duty Cycle of the compressors and the extended Change Intervals all adds up to Lots of $$$ in Industrial/Commercial Apps.

Synthetic Compressor Oil is Crazy Expensive---$15~20+++ per Qt.

Mobil 1 Synthetic,,,just the commonly available Motor Oil,,,is increasingly coming to be recommended by various compressor manufacturers as an "Official Substitute"

What's notable about that is some of them specify their regular compressor oil for Standard Duty Service around 60% Duty Cycle,,,40~45 minutes per hour.

and then specify Mobil 1 for 100% Duty Cycle--where the compressor runs all day long,or hours on end.

So it seems to boil down to:

*OFFICIALLY>>Specific Labeled Compressor Oil

*Generically>> 30 weight (+/- depending on climate) NON-Detergent Motor Oil

*Heavy Duty/Extreme Service>> Any Synthetic Compressor Oil,,or Mobil 1 Synthetic motor oil

*"Emergency/Worst Case">> in a situation where nothing else is available and oil MUST be added,,,,any conventional Motor Oil will do....even Hi-Detergent(which is technically WRONG)

best choice would be a Single Weight Oil,,straight 30 weight.

For Real & Valid Reasons It's NEVER recommended,,,

but in real-world experience it's been used for decades without causing any obvious harm.

Personally--I would not hesitate to use it if I Had To,,

but I would replace it with "proper" oil soon as I could .

Hope that helps

Happy Holidays