Air compressor oil

[vpt]

I was always taught non detergent for systems with no filter so particulates fall to the bottom. With systems that have a filter use detergent oil to suspend particulates to be filtered out.


I haven't changed the oil in my compressor yet. It is due I am sure. I'm just gonna get some ND 30w and let her chooch. If she blows she blows, compressor heads are cheap.

[3 Phase Lightbulb]

I use Mobile 1 synthetic 5w30 in my compressor (after it was broken in)

[wierdscience]

I use Mobile 1 synthetic 5w30 in my compressor (after it was broken in)

Probably fine,Mobil 1 being full synthetic probably is already low ash and anti-foaming.

[wierdscience]

For 2-stage compressors where the temps get high DIN 51506 VDL might be good specification to look for.
Carbon/ash buildup seems to be the main reason to avoid multi-weight oils as viscosity index modifiers and detergents make more carbon buildup. (Some compressor oils seem to come with ashless detergents)

The best ones are usually just base oils with maybe some anti-foaming additive.

[wierdscience]

I was always taught non detergent for systems with no filter so particulates fall to the bottom. With systems that have a filter use detergent oil to suspend particulates to be filtered out.


I haven't changed the oil in my compressor yet. It is due I am sure. I'm just gonna get some ND 30w and let her chooch. If she blows she blows, compressor heads are cheap.

Compressors are basically 100 year old internal combustion engines without the ignition system,carburator and camshaft.There just isn't a need for all the additives and detergents,mainly because there are no combustion products to get past the rings.

[3 Phase Lightbulb]

Probably fine,Mobil 1 being full synthetic probably is already low ash and anti-foaming.

IIRC, the manual actually suggested Mobil 1 synthetic.

[vpt]

Compressors are basically 100 year old internal combustion engines without the ignition system,carburator and camshaft.There just isn't a need for all the additives and detergents,mainly because there are no combustion products to get past the rings.

Yes. I feel people put way to much thought and worry into oils now days. Even in cars as long as you change it oil related problems just aren't a problem any more. Doesn't matter what oil.

[DS_park]

I was always taught non detergent for systems with no filter so particulates fall to the bottom. With systems that have a filter use detergent oil to suspend particulates to be filtered out.


I haven't changed the oil in my compressor yet. It is due I am sure. I'm just gonna get some ND 30w and let her chooch. If she blows she blows, compressor heads are cheap.

+1.
Even with no oil filter, regular oil changes will eliminate the suspended stuff. Millions of air-cooled VW bug motors (no oil filter) lived long happy lives on detergent oil with regular changes of course. Even back in the 80's Sears lawn mowers were delivered with a bottle SAE detergent oil.

Probably most important, regardless of the oil selected, is to do the first oil change which flushes out all the break in particles.

[Willy]

I have to agree 100% with not only with the recommendations as laid out by weirdscience but also his anecdotal references and experiences, I've seen the same results in heavy duty industrial quality compressors.

While just about any oil that would be considered for use in an air compressor will offer decent lubricating qualities, rust and oxidation protection, and anti foaming additives, the key difference in any good air compressor oil is that it is designed to shed water and keep it out of suspension rather than turn it into an emulsion. And yes I agree, not only are additive packages that are required in fuel burning engines not needed, they can be detrimental in air compressor applications.
Rememember that an additive package can constitute up to 25% of an oil's volume so it is definitely a factor.
I'm sure that in light of this OEMs often times don't want to over complicate their recommendations by saying, for instance that oils with ashless dispersants are okay as it only confuses the issue, they need to keep their guidelines simple even though other types of oils may be acceptable.

As always it's best to follow the lube recommendations of the manufacture, he knows the design parameters of the unit better than anyone and has the most to gain by his product exceeding customer expectations.

When I bought my compressor back in 1975 or 76 I lost the owners manual that accompanied the unit and when it was due for it's annual oil change, not knowing any better at the time, I simply used a good quality 10w30 motor oil and have continued to do so ever since, religiously once a year. In retrospect the saving factor is probably the low duty cycle it sees as it seldom gets really hot since most use is intermittent. However I will continue to use the 10w30 motor oil in light of the excellent service it has shown, as the only work required to the compressor in close to 45 years was an oil seal replacement about 25 years ago.
I equate the service it sees to an air compressor as used on air brake equipped vehicles, intermittent duty, engine oil lubricated.

The best recommendation I can give though is to follow OEM lube requirements, change oil at least annually and keep the air going into the unit clean.