James Hinchcliffe topped the second practice session at Barber Motorsports Park, and was the only driver to set a time underneath a 1:09, laying down a 1:08.999.
The difficult track layout proved to be a challenge for a number of drivers who found themselves taking trips through the grass and gravel.
One driver ended up in the barrier, with the Dayle Coyne car of Santino Ferrucci going off, but managed to get away without any major damage, and ended up third in the session..
IndyCar's latest race-winner Colton Herta was second, as he too had an off towards the end of the session, taking to the grass and following the route until he could rejoin the circuit.
There is some doubt over the pace of the red Firestone tyres, which are designed to be the quicker tyre ahead of the 'blacks.' However, a number of drivers struggled on the stickier tyre, with Andretti's Zach Veach confirming after the session that he is not so sure which is quicker.
The second Dale Coyne Racing car of Sebastien Bourdais was fourth, beating the leading Andretti of Alexander Rossi, who edged out teammate Ryan Hunter-Reay.
After causing a late red flag late on in the first practice session, Spencer Pigot ended the day in seventh, ahead of Patricio O'Ward, Marco Andretti and the reigning series champion Scott Dixon.
|1.||James Hinchcliffe||Schmidt Peterson Motorsports||1:08.9994|
|2.||Colton Herta||Harding Racing||1:09.0084||+0.0090|
|3.||Santino Ferrucci||Dale Coyne Racing||1:09.0461||+0.0467|
|4.||Sebastien Bourdais||Dale Coyne Racing||1:09.0968||+0.0974|
|5.||Alexander Rossi||Andretti Autosport||1:09.1140||+0.1146|
|6.||Ryan Hunter-Reay||Andretti Autosport||1:09.1545||+0.1551|
|7.||Spencer Pigot||Ed Carpenter Racing||1:09.2055||+0.2061|
|9.||Marco Andretti||Andretti Autosport||1:09.3113||+0.3119|
|10.||Scott Dixon||Chip Ganassi Racing||1:09.4079||+0.4085|
|11.||Will Power||Team Penske||1:09.4166||+0.4172|
|12.||Zach Veach||Andretti Autosport||1:09.4320||+0.4326|
|13.||Takuma Sato||Rahal Letterman Lanigan Racing||1:09.4532||+0.4538|
|14.||Marcus Ericsson||Schmidt Peterson Motorsports||1:09.5385||+0.5391|
|15.||Simon Pagenaud||Team Penske||1:09.5546||+0.5552|
|16.||Graham Rahal||Rahal Letterman Lanigan Racing||1:09.5660||+0.5666|
|17.||Felix Rosenqvist||Chip Ganassi Racing||1:09.5986||+0.5992|
|18.||Josef Newgarden||Team Penske||1:09.6309||+0.6315|
|19.||Jack Harvey||Meyer Shank Racing||1:09.8179||+0.8185|
|20.||Matheus Leist||A.J. Foyt Enterprises||1:09.8893||+0.8899|
|21.||Tony Kanaan||A.J. Foyt Enterprises||1:09.8971||+0.8977|
|22.||Ed Jones||Ed Carpenter Racing||1:10.0486||+1.0492|