The roles of various fillers, i.e. short carbon fibers (SCF), graphite, hexagonal structured tungsten disulfide (WS₂) and aluminium nitride (AlN) nanoparticles, on the tribologial performance of polyphenylene sulphid (PPS) were explored with low-sulfur diesel as lubricant. It was demonstrated that the nanoparticles, especially AlN, remarkably improved the tribologial performance of PPS composites under diesel lubrication conditions. Moreover, presence of only very limited quantity of diesel results in the best tribological performance. It was manifested that the tribological performance was closely dependent on the tribofilm formed on steel counterface. Tribo-chemical reactions of PPS with both the steel counterpart and AlN nanoparticles were identified, as deemed important for generation of a robust tribofilm.