Nowadays, the automotive engines are downsizing, thus offering limited space for engine intake air filter media. This results in higher aerosol velocity through the filter media. At a higher velocity, the aerosol particles reenter into the fluid stream and thereafter penetrate through the filter media. This causes significant reduction in filtration efficiency. Here, an attempt is made to understand the particle penetration behavior of automotive engine intake air filter media. To establish the flow field, numerical simulations are carried out on a panel type pleated air filter with pleat height 26 mm, pleat pitch 4.5 mm and pleat angle 2.50 degree. A series of tests are conducted using ISO 12103 A2 fine dust on a flat cellulosic paper filter media at a range of velocities derived numerically. The methodology followed for modeling the fibrous media using finite volume commercial CFD code for analyzing the flow field is presented. The calculations of pressure drop are compared with the experimental measurements. Further CFD calculations of the flow field in the pleat region serve as input concerning the velocities for flat sheet testing of dust loading. Filtration efficiency as a function of pressure drop is studied to understand the particle penetration during dust loading. An increase in particle penetration is observed with the increase in face velocity.