This paper presents a new tri-component diesel surrogate fuel chemical kinetic mechanism. The cross reaction mechanism between N-heptane and toluene is added to the third component detailed mechanism of cyclohexane. Based on the composition of the diesel fuel, N-heptane, toluene, and cyclohexane are selected as ideal components for this new diesel surrogate fuel. The best ratio of the selected diesel surrogate fuel components, which representing heptanes, toluene, and cyclohexane with a ratio of 8:1:1 is determined for the three suggested components. Numerically, the result obtained from a Zero-dimensional thermodynamic code for the proposed tri-component mechanism have been intensively validated against a single, and two components detailed chemical kinetic mechanism. Furthermore, the obtained results validated against the referenced experimental engine data. The obtained results of the tri-component mechanism provide a remarkable agreement between the obtained experimental data in terms of ignition delay angles. The obtained results of ignition delay angles show that the suggested chemical kinetics mechanism can capture the auto-ignition angle and the whole combustion process.