What does compressor oil do and what is it composed of? Does it have to be from synthetic base? What kind of additives are added in? Would appreciate if anyone could give information on this, or where can i get the info? thanks.

This question has as many answers as there are compressor styles. Lubricants are selected for the application specific properties they posess. A compressor oil used in a reciprocating piston type compressor may not be the best choice for a rotary screw or axial turbine style of compressor. Compressor oils generally need to have very high oxidation stability due to the high temperatures associated with compressing gasses. If the oil is in contact with the medium being compressed such as in a flooded screw compressor then it needs to be compatable with the compressed gas. Synthetics offer better performance in most instances. Consult with your lubricant supplier, Equipment manufacturer, and a compressor service company such as John Henry Foster for answers to your specific application. You might d a web search on "compressor oils" to locate some inforamtion. Here is a link to a white paper detailing a study done by Amsoil on compressor fluids; http://www.lube-power.com/whitepaper.html A good comprehensive book on general lubrication for industry is "Practical Lubrication for Industrial Facilities" by Heinz P. Bloch, P.E. It can be purchased either from Noria's bookstore or Amazom.com