There has been an increased focus on using gasoline direct injection engines operating at the stoichiometric point due to their potential to improve fuel economy. Nonetheless, particulate matter emitted by gasoline vehicles negatively affect human health. Gasoline particulate filters are the most promising technology in the reduction of particulate matter emissions along with fuel efficiency. Depending on the particle’s size, its deposition and trajectory highly depend on flow pattern; however, the flow regime within gasoline particulate filters is still yet to be solved. The present investigation uses a representation of a gasoline particulate filter to demonstrate the effects of turbulence in the flow behaviour therein. These effects are analysed utilising different Reynolds-average-Navier-Stokes models and the laminar model with inflow velocities and filter wall permeability. The results demonstrate that turbulence significantly modifies flow pattern within the channels and porous wall as well as the pressure drop.