A three-ball-on-disk (TBOD) bench test has been developed to evaluate high-temperature liquid lubricants such as the polyphenyl ethers. The TBOD test method is capable of generating an integrated set of tribo-measurements including friction, wear, lubricant consumption, and lubricant tribochemistry. Unlike the four-ball wear test, well-defined wear scars of circular and elliptical shapes are exclusively produced, which is critical for precise wear volume calculation.Presented at the 48th Annual Meeting in Calgary, Alberta, Canada May 17–20, 1993