prerunner is a 2wd tacoma with the looks and suspension of a 4wd. S-runner is a 5-lug sporty truck with a 3.4l v-6 produced from '01-'04. The x-runner is like the new version of the s-runner, it is a sporty truck with ground effects packing the 4.0l v-6 produced from '05 and up.