The legendary racing name Unser is a surname shared by four generations of race car drivers from the Unser family. Al Unser Sr. was an American race car driver who won the Indianapolis 500 four times, making him one of only three drivers to have done so. Al Unser Jr. is also an American race car driver who won the Indianapolis 500 twice and the CART championship four times. Bobby Unser was an American race car driver who won the Indianapolis 500 three times and the USAC National Championship twice. Al Unser III is an American race car driver who has competed in the IndyCar Series and the NASCAR Xfinity Series.