A hydrotreated diesel supplied by t

A hydrotreated diesel supplied by the Qilu Petrochemical Company was adopted as the test fuel in this study,with its typical properties listed in Table 1. The sulfur and nitrogen content of the diesel was determined using an Antek 9000 sulfur and nitrogen fluorescence analyzer.Density, viscosity, and distillation range of the diesel sample were determined according to the standard method GB/T 2540—1981, GB 265—1975, and GB 255—1977,respectively. Additives were added to the test fuel in a concentration range from 50 μg/g to 500 μg/g. All lubricity measurements were performed by the High-Frequency Reciprocating Rig (HFRR) apparatus according to the ISO-12156 method.