Tractor pulling, also known as power pulling, is a competition using tractors to pull a heavy sle along a 'track' and is very popular in rural areas. Usually the sled offers progressively greater resistance as it is pulled. It can be a great spectacle, and although the vehicle produces a great deal of noise and smoke and throws dirt everywhere, it doesn't actually travel very far. There are many different classes, from 'factory' tractors to custom built vehicles with multiple engines. There are even one tenth scale radio control (R/C) models that pull scale sleds.