Six teams from the IZOD IndyCar® Series completed a one-day test session at Sonoma Raceway on Wednesday.

Ten drivers took to the 12-turn, 2.38-mile road course in preparation for the GoPro Grand Prix of Sonoma, Aug. 23-25. It marked the first of three scheduled INDYCAR tests in Sonoma for the year, with the others slated for August, just days before the main event. 

Participants in the test included KV Racing Technology drivers Tony Kanaan and Simona De Silvestro. Kanaan won the inaugural INDYCAR race in Sonoma in 2005 and was the 2004 series champion.

Other teams included Panther Dreyer & Reinbold Racing (Oriol Servia), Dragon Racing (Sebastien Bourdais and Sebastian Saavedra), Schmidt Peterson Motorsports (Simon Pagenaud and Tristan Vautier), Ed Carpenter Racing (Ed Carpenter) and Panther Racing (JR Hildebrand).

“This time of year, the track is green and the grass is keeping the sand and dust from going on the track. This is a great time of year to be out on track. Run to run, morning to afternoon, things are much more consistent,” said Hildebrand, a native of nearby Sausalito. “Once you get into summer, that element changes. It’s a very temperature-sensitive track. As far as the actual track conditions go, they are always a little bit different.”

IZOD IndyCar Series champion Ryan Hunter-Reay made a surprise visit to the test, taking the wheel of Carpenter’s No. 20 entry in a collaborative effort between Ed Carpenter Racing, Andretti Autosport and Team Chevy to work with various components.

“It’s been very good today. We are working through some methodical changes that Ed Carpenter Racing had coming here and we’re working on a few things for Chevy, so we’re getting a lot done in a short amount of time,” Hunter-Reay, who finished 18th at Sonoma in 2012 after an on-track incident with Alex Tagliani.

Sonoma Raceway will host the GoPro Grand Prix of Sonoma, Aug. 23-25.  The weekend will also feature the Maserati Trofeo World Series, the SCCA Pro Racing World Challenge and the Formula Car Championship.  For more information or to purchase tickets, call 800-870-RACE (7223) or visit