All terrain vehicles (ATV) travel on every imaginable type of surface — from hard pack trails to muddy swamps. ATV tires must provide customer with acceptable ride and handling performance, and they must also generate extremely good wet traction characteristics in order to pull the vehicle through the tough stuff. This paper looks at a design tool that is routinely used to achieve one of these goals — optimum mud (wet) traction performance. Techniques described in this study evaluate the self‐cleaning ability of tread patterns. Smooth tires were modeled at typical vehicle loads and inflation pressures using finite element analysis. Footprint shapes and pressure distributions were taken from the analysis and used as input into the flow model. Mud was modeled as a highly viscous, Newtonian fluid and forced through the tread pattern. Flow velocities and pressures were computed using computational fluid dynamics and these responses were used to generate an overall measure of the cleaning efficiency of the tread. By visualizing the results, potential “clog” areas were identified and the tread pattern modified to improve flow.