Viewing the Tire Rack website for a set of tires. Through the end of the month they offer a $75 rebate on selected Kuhmo tires. After the rebate, a set of four PA31 tires costs $156 in a 205-50-15 size. (This size is virtually the same diameter as the original 185-55-15 that comes with the Spark EV.) Of course, shipping adds about another $65-70, but still a bargain. If you want to replace using the exact same size as originally equipped, both the PA31 and the Ecsta 4X II offer the 185-55-15 and 195-55-15 sizes.