Worthington Compressor Services Petrolube series is specifically designed to be used on all reciprocating compressors currently using a standard petroleum based lubricant. What separates the Worthington product from the standard petroleum is the process with which the Petrolube is made. We start with highly refined base stocks and add a proprietary additive which inhibits the formation of varnish and carbon while providing superior thermal and oxidative stability.Petrolube is sold in the standard SAE 20, 30 and 40 weights.