Certain polyalkylene glycols, useful as lubricant additives, are soluble with all four types of hydrocarbon base oils (Groups I-IV) at a wide variety of ratios of oil to polyalkylene glycol and under a variety of conditions. These polyalkylene glycols are prepared by reacting a C8-C20 alcohol and a mixed butylene oxide/propylene oxide feed, wherein the ratio of butylene oxide to propylene oxide ranges from 3:1 to 1:1. The invention provides a means of providing desirable lubricant compositions which may pose fewer environmental problems.