Evolutionary topology optimization using design space adjustment and refinement is used to optimize a knuckle in the suspension system of an automobile. Design space optimization used in this paper is a new efficient method for large-scale topology optimization by virtue of two reasons. First, the design space adjustment including multi-layer design space expansion and reduction is suitable for large-scale problems by virtue of its evolutionary nature. Second, the design space refinement can be done locally or globally when and where necessary and thus is very effective in obtaining a target resolution with much less number of elements. Minimum compliance for a knuckle is considered with the actual working condition to show the effectiveness and superiority of the new approach.