The paper aims at numerically modeling the flow and thermal processes occurring in an agricultural tractor using Computational Fluid Dynamics (CFD) and determines the comfort level of the tractor operator during working condition. The motive of the investigation is to develop and demonstrate capabilities of CFD as an automotive analysis tool. The work describes a methodology that significantly stream lines the process of thermal flow taking place in a tractor by utilizing state-of-the art computer simulation of air flow and heat transfer.The numerical investigation carried out with a three-dimensional geometry of the vehicle assembly and the measurements were taken from the vehicle. The geometry created with Pro/Engineer formed the domain for the automatically generating discretized grid contained the majority of the main components within the underhood environment. The boundary conditions selected and applied to the numerical model, best represent the conditions present with the experimental tests. Subsequently, the boundary conditions and numerical models were applied to the grids in FLUENT . The 3D fan model with actual geometry simulated using Multiple Reference Frames (MRF) method  and momentum source has captured the effects very well. The energy sources are captured from the effect of engine and exhaust system. The analysis concluded with results obtained from the numerical CFD simulations performed using commercial solver. The validity and accuracy of the numerical solutions were verified and quantified with the experimental results.The parametric study consisted of two test cases: 1Vehicle in stationary condition with fan active2Vehicle in moving condition with the fan active.Accuracy of the CFD simulations, predicted temperatures throughout the under hood was determined using numerical sensors placed in the model at identical positions as the thermocouples in the experimental tests. The comparison of the experimental and numerical results for the temperatures indicated that, although the under hood compartment used in the numerical simulations was significantly simplified, the simulations were still capable of predicting the temperatures with an acceptable level of accuracy.