PAO stands for polyalphaolefins; commonly referred to as synthetic hydrocarbons, these base fluids are the most widely used variety of synthetic oil blends mainly for their ability to maintain performance in spite of temperature extremes and their similarity to - but improved performance over - mineral oil base fluids. Synthetic PAO Compressor Oils are intended for use in various types of air compressors including reciprocating, centrifugal, and rotary screw compressors and are especially useful in situations where mineral oil-based products are not up to the task of severe applications where high pressures and temperatures can be an issue.
ISO VG 46 oil has a midpoint kinematic viscosity of 46 mm2/s, also referred to as centistokes (cSt). The midpoint is derived by taking the average of both the minimum and maximum kinematic viscosities. In the case of ISO VG 46 oil, those numbers are 50.6 cSt and 41.4 cSt, respectively. These numbers refer to the standard testing mechanisms used to determine how much resistance to flow (i.e. viscosity) these oils demonstrate.