I know the manual for my new compressor suggests straight 20 or 30 weight motor oil. But I'm wondering if anyone has another preferred case oil for their compressor. I need an oil light enough to contend with outside winter temperatures. I've heard that Marvel Mystery oil works and have even had Mineral Oil suggested. Your thoughts, please. Dave Brown Heritage Smithing Green Bay, WI ABANA, UMBA, GoM, MODA, ARG