CITGO CITGEAR Synthetic PAG (polyalkylene glycol) Gear Fluids are premium polyalkylene glycol lubricants formulated to provide excellent performance in gear boxes, worm gears, bearings, blowers, reciprocating compressors, and hydraulic systems beyond the capabilities of mineral oils. Not miscible with mineral oils and should not be used as make-up for systems filled with conventional mineral oils. Mineral oils should not be used as top-off for systems which contain CITGEAR Synthetic PAG Gear Fluids. CITGEAR Synthetic PAG fluids are hygroscopic and do not separate from water. As a result, water does not settle to the bottom of the systems reservoir.