Iowa IndyCar: Tony Kanaan leads practice for Ganassi and Chevrolet

The 2010 race winner's timesheet-topping lap was just his fifth of the 75-minute session, Kanaan setting a 17.2197-second lap amid a disjointed start.

Andretti pair Marco Andretti and Ryan Hunter-Reay both fell victim to kicks of oversteer in Turn 4 in separate incidents just 15 minutes in.

Bumpy patches in the latter half of the lap from last month's NASCAR Xfinity Series race are thought to have contributed to their spins, resulting in other drivers in the paddock adjusting rear wing settings to compensate for the unpredictable asphalt.

Andretti managed to avoid the barriers but three-time Iowa race winner Hunter-Reay was less fortunate, losing the rear into the wall and requiring a rear wing change.

Both were able to return to the track in the final 30 minutes to finish ninth and 16th respectively - which meant top Honda honours for Hunter-Reay in the Chevrolet-dominated session.

The session was largely quiet after the early spins but entertainment came courtesy of Ed Carpenter Racing duo Josef Newgarden and Ed Carpenter, who attempted some slipstreaming.

Newgarden finished third 0.0293s behind Kanaan's time, with Helio Castroneves second for Penske with a 17.2417s.

Championship leader Simon Pagenaud ended practice fifth behind reigning champion Scott Dixon.

Former Formula 1 pair Alexander Rossi and 2015 Iowa Indy Lights race winner Max Chilton completed the session in 11th and 12th respectively, 0.2s off Kanaan's pace.

PRACTICE TIMES