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 km). It originally used production-model cars, hence the name "stock car", but is now run using cars specifically built for racing. It originated in the southern United States; the world's largest governing body is the American NASCAR. Its NASCAR Cup Series is the premier top-level series of professional stock car racing. Australia, Canada, New Zealand, Mexico, Brazil and the United Kingdom also have forms of stock car racing. Top-level races typically range between 200 and 600 miles (322 and 966 km) in length.