The identification of tribofilm wear mechanisms is further perplexed by antagonistic effects between additives and dispersants. Under certain conditions, the effectiveness of an additive could be reduced in the presence of a dispersant [
31,
32,
33]. Dispersants are used to sustain the stability and cleanness of oil blends by inhibiting the agglomeration of wear debris [
34], or nanoparticles used as lubricant additives [
35]. For instance, different chemical interactions and tribological characteristics were found when detergents and dispersants were incorporated in a base oil that contained ZDDP [
24,
36,
37,
38]. Succinimides represent a common class of dispersants, whether simultaneously used with additives or alone in fully formulated lubricants [
24,
34,
35,
39]. These dispersants undergo adsorption on steel surfaces, forming nanometer-thick boundary films. Nevertheless, high dispersant concentration levels may suppress tribofilm formation [
40], or the dispersant might become ineffective in reducing wear when the tribofilm is highly degraded because it could be entirely consumed in dispersing the wear debris [
41]. However, while incorporating a succinimide dispersant in base oil can effectively disperse the wear debris, it cannot provide significant wear protection in the absence of an antiwear additive [
34]. Chemical interactions between ZDDP and different nitrogenous dispersants have been reported to produce different friction behaviors, illuminating varying levels of competitive effects of these additives on friction characteristics [
38]. Indisputably, understanding these antagonistic effects between additives and dispersants is critical for developing lubricant formulations that provide a balance between tribofilm antiwear properties and lubricant stability and cleanness
