Another Oil Thread, but for Air Compressor Oil

[Tom Wesenberg]

I have a small 3/4 H.P. 4 cylinder Craftsman air compressor that I bought at an auction a few years ago. I'll be changing oil for the first time since I bought it. It's too hard to get running when the temp gets below 55 degrees, so I need a lighter oil. I've always read that air compressors should use non detergent oil, as the detergent oil leaves the valves with a residue. I did a Google search for the best air compressor oil to use, and there was a wide variety of opinions, along with some sound information. It seems Mobil 1 synthetic oil is also OK to use, so I'll try a light weight of that, as my compressor sets out in the cold.

This compressor has 4 very small pistons, so it gives a nice even flow and is very quiet running. I believe it was sold mainly for spray painting, and should not be run any higher than about 75 PSI. I think it was made in the 50's or 60's.

[Mitch]

I know people that run a lighter weight detergent oil in their compressors and they hold up fine.

[DaWizard]

I agree with Mitch, I think the most important thing is to be sure it has oil, and there is nothing wrong with a lighter oil year round.

[Tom Wesenberg]

Choosing a motor oil can make your head spin. Here's a link to just Mobil 1 synthetic, let alone all the other oils Mobil sells. I think they even have a special oil if your car has just push button tuning, instead of signal seeking. This is nuts trying to figure out what oil a person should use. I thought Mobil 1, then pick the weight you want, if you choose synthetic, but there are 10 different Mobil1 oils in this link, plus Mobil now sells other full synthetic oils that aren't called Mobil1.

https://mobiloil.com/en/motor-oils/mobil-1

[Mitch]

Always use the flavored spec the car calls for.

[Big-Foot]

A good friend of mine is/was one of the head plant engineers for Beuller Corp and has built dozens of large (we're talking in excess of 100k sq ft) diecast and foundry operations before he started his consulting business. He swears by using Mobil1 10w30 motor oil in his compressors. I switched to this a good 20 years ago and have never yet been disappointed. My compressors run a bit quieter as well which is a bonus..