In the present study, a numerical analysis of the three-dimensional heat transfer and fluid flow for a vehicle cooling system was developed. The flow field of the engine room between the grille and radiator was analyzed. The results show that, as the airflow inlet grille angle $alpha$ is varied from $15^{circ}$ to $-15^{circ}$, the air flow rate compared with $alpha=0^{circ}$(horizontal) changes from -11.9% to +5.1%; while the heat flux from the radiator changes from -9.2% to +4.4%. When the airflow inlet bumper angle $eta$ is varied from $-5^{circ}$ to $+15^{circ}$, the heat flux from the radiator compared with $eta=0^{circ}$(horizontal) increases up to +4.4%. When the airflow inlet grille angle $alpha=-15^{circ}$ and the bumper grill angle $eta=+15^{circ}$, the airflow rates and heat flux compared with($alpha=0^{circ}$, $eta=0^{circ}$) can be increased to +9.5% and +7.5%, respectively. The results indicate that the optimal angles for cooling efficiency are used.