depending on the size of your compressor and if there are coolers on it ,at work, we used Lubrication Engineers Monolec comp/turbine oil in the iso -100 , in 25/30 hp Ingersol Rand,they ran 24/7 with unloader valves about fifty percent on average,,LE performed noticeably better than the Mobil overall, less wear and cleaner insides when we tore down for inspections and repair. I also used some Schaeffer's oils with real good results on some other compressors and vacuum pumps for back up use.