High Quality Content by WIKIPEDIA articles! The 1991 IndyCar season, the thirteenth in the CART era of U.S. open-wheel racing, consisted of 18 races, beginning in Surfers Paradise, Queensland, Australia on March 17 and concluding in Monterey, California on October 20. There was one non-championship event, the Marlboro Challenge. The PPG Indy Car World Series Drivers` Champion was Michael Andretti, the Indianapolis 500 & Marlboro 500 winner was Rick Mears. Rookie of the Year was Jeff Andretti. The 75th Indianapolis 500 was sanctioned by the USAC, but counted in the CART points standings.