n [ U ]
a popular type of car racing in the US. The cars are like those used for the Indianapolis 500 . They are very powerful and can go at more than 230 miles/370 kilometres per hour. Drivers compete in a season of 16 Champcar races between March and September to win the IndyCar World Series. The races are mostly in the US but some are also held in Canada, Australia and Brazil. The Championships were started in 1916 by the American Automobile Association.