This document specifies a test method using the high-frequency reciprocating rig (HFRR), using a digital camera, for assessing the lubricating property of petroleum-based middle distillate fuels, paraffinic diesel fuels, and biodiesel blends, with and without lubricity enhancing additives, with HFRR wear scar diameters (WSDs) of 350 ¼m to 700 ¼m. This test method applies to fuels used in diesel engines. NOTE It is not known if this test method will predict the performance of all additive/fuel combinations.