In this study the linear mixing rules were tested for mixtures representative of diesel fuels. First, we defined a set of mixtures containing various proportions of six components that represent the main chemical families in diesel fuel. The mixture matrix followed a formal experimental design to ensure that it sampled the full chemical space possible with six components. The ρ of these mixtures were measured, then the results were fit to Eq. ( ). Similarly, the YSIs of the mixtures were measured, then fit to Eq. (4).