I only use a Diesel engine oil.....have done for the past 10-twenty years with no problems.....
To replace my big Broom-Wade piston compressor would be over £8,000....so plenty to worry about..In various locations I have 5 comp running with the same oil...
as an add on.....
all my metal lathes and milling machine gearboxes get the Red automatic gear box oil from the automotive scene...