Team Penske-Chevrolet stretched its legs at the start of the the second session, but it was the Chip Ganassi Racing-Honda of Scott Dixon which set the fastest speed of the day so far at 224.795mph.
Will Power was first to go past the 222mph mark in the four-hour second session, and then his Penske teammates Helio Castroneves and Josef Newgarden towed each other around so that the three-time Indy winner and series returnee briefly sat atop the speed charts with a 223.495.
However, 2013 Indy 500 winner Tony Kanaan then put his AJ Foyt Racing-Chevrolet on top with a 223.922mph on his 17th lap.
Then erstwhile teammate Dixon, the 2008 Indy winner and four-time series champion, ran his 224.795 to become the only Honda runner in the top seven.
When the yellow flags waved for a track inspection just before the halfway point of the session, Kanaan’s speed was still P2 ahead of the four Penskes led by Simon Pagenaud, whose fastest trap speed was a stout 233.566mph.
Spencer Pigot, who was recently confirmed as racing for Mazda at this weekend’s IMSA round in Mid-Ohio was seventh quickest for Ed Carpenter Racing-Chevy, just ahead of the Andretti Autosport cars of 2016 Indy winner Alexander Rossi and 2014 winner Ryan Hunter-Reay.
Defending race winner Takuma Sato completed the top 10 for Rahal Letterman Lanigan Racing-Honda.
The Carlin-Chevrolet drivers moved up the leaderboard, with Charlie Kimball P16 and Max Chilton P19.