I changed the oil in my bike 3 times this year and only have 2500 miles - but I've got several years on my compressor and haven't changed the oil yet.
I can't find an owners manual but the last time I talked to anybody about air compressor oil, I was told to use a non detergent oil because it didn't foam - is that still the way to go ??
btw it's a 220 volt 175 psI