A stock car is a car which has had changes made to it so that it is suitable for races in which the cars often crash into each other.
Stock car racing is a form of automobile racing run on oval tracks and road courses measuring approximately 0.25 to 2.66 miles (0.4 to 4.3 kilometers). It originally used production-model cars, hence the name "stock car", but is now run using cars specifically built for racing. It originates from the United States and Canada; the world's largest governing body is the American NASCAR.
Top-level stock cars exceed 200 mph (322 km/h) at speedway tracks and on superspeedway tracks such as Daytona International Speedway and Talladega Superspeedway.
Contemporary NASCAR-spec top-level cars produce maximum power outputs of 860–900 hp from their naturally aspirated V8 engines. In October 2007 American race car driver Russ Wicks set a speed record for stock cars in a 2007-season Dodge Charger built to NASCAR specifications by achieving a maximum speed of 244.9 mph (394.1 km/h) at Bonneville Speedway. For the 2015 NASCAR Cup Series, power output of the competing cars ranged from 750 to 800 hp (560 to 600 kW).