Leisure hours last year ran 19 turn truck and a Mod class. 19 turn truck is the most popular. Mod is where u would run a buggy or truck against people with faster and more expensive motors, generally around 12 turn. A stock motor is around 27 turns. Consider this if looking at rtr's and try to get a motor size to suit the racing u want to do. The associated or losi both have nice trucks. the associated is the most popular at leisure.