This paper deals with the simulation of car suspension parameter impact on the contact between the tyre and an uneven road. The simulation was based on the quarter car vehicle model used for the analysis of vertical vibrations of sprung and unsprung mass under the influence of discrete road unevenness. The parameters of the model relate to the front axle of a VW Passat B5. Suspension and damping characteristics were described by non-linear functions. The results included in the paper cover the influence of changing the rebound damping force, main spring stiffness coefficient and the unsprung mass on active safety and ride comfort.