A working group of the International Organization of Standardization (ISO), in cooperation with the Coordinating European Council (CEC), has conducted a round robin test program to compare laboratory bench tests to evaluate the lubricity characteristics of diesel fuels. The goal of the ISO program was to generate sufficient data from these test methods and from fuel injection equipment performance tests to select a test method for determining diesel fuel lubricity. The ISO group also aimed to produce sufficient information to define a minimum lubricity level that would protect fuel delivery system components.Four laboratory test methods were included in the program. These consisted of Falex's Ball on Three Seats (BOTS), Lubrizol's Modified Ball-on-Cylinder Lubricity Evaluator (BOCLE), Paramins' High Frequency Reciprocating Rig (HFRR), and the U.S. Army's Scuffing Load BOCLE. In-house injection equipment testing was conducted by Bosch, Lucas, and Stanadyne using rotary distributor pumps, and by Cummins Engine Company using unit injectors. Twelve fluids were evaluated in this program by 28 participants in Europe and North America.This paper provides a summary of the round robin test program, the statistical analysis of the data, and the conclusions which led to the selection of the high frequency reciprocating rig (HFRR) and a proposed ISO diesel fuel lubricity limit.