The Star Mazda Championship and World Challenge Series will be a part of the Indy® Grand Prix of Sonoma weekend, Aug. 26-28, at Infineon Raceway.

The two series will add to an already action-packed race weekend in Sonoma, which also includes the Formula Car Challenge, presented by Goodyear (www.formulacarchallenge.com), and the always-popular Historic Grand Prix (www.historicgrandprix.com). That makes five different racing series battling on the challenging road course, headlined by the IZOD IndyCar® Series.

It will be a double-header weekend for the World Challenge, with 50-minute timed feature races set for Saturday and Sunday of race weekend in all three classes: Grand Touring (GT), Grand Touring Sport (GTS) and Touring Car (TC). The World Challenge is known for its exciting standing starts, as well as action-packed racing. Fans can expect such makes as Toyota, Corvette, Cadillac and Porsche on the road course. This marks the World Challenge's first visit to Sonoma since 2006 (www.world-challenge.com).

The Star Mazda Championship, presented by Goodyear, is making its first appearance at Infineon Raceway since 2005 and can count among its graduates INDYCAR drivers Marco Andretti, Graham Rahal and Raphael Matos, as well as former NASCAR Sprint Cup Series star and Manteca native Scott Speed. The Star Mazda Championship will run alongside the IZOD IndyCar Series six times during the 2011 race season. The Star Mazda Championship will run its feature race on Saturday of race weekend (www.starmazda.com).

The main event of the weekend, the Indy Grand Prix of Sonoma, featuring defending Sonoma champion Will Power, 2010 series champion Dario Franchitti and Danica Patrick, will take the green flag on Sunday, Aug. 28.

For more information about the event weekend or for tickets call 800-870-RACE or visit www.infineonraceway.com/indycar.