Will Power headed the speed charts ahead of Penske team-mate Simon Pagenaud on a clear day, with Chevrolet occupying the top four places in the first practice session ahead of the 103rd running of the Indianapolis 500.
The 2018 winner set the field ablaze with his #12 5G entry with a 229.745mph average speed lap across the 2.5mile oval with Indy GP race winner Pagenaud narrowly behind on a 229.703mph lap. They were the only pair to cross over the 229mph barrier.
Ed Carpenter ended the day in the third in the #20 entry, he was fastest in the morning session before the refresher and RoP group hit the circuit. His best speed of the afternoon came in at 228.653mph.
Helio Castroneves in the #3 Pennzoil, who is in search of a fourth win at the famous Brickyard finished the session fourth as Chevrolet occupied the top four spots with a 228.441mph average speed, making it three Penske cars inside the top four.
Harding Steinbrenner Racing's Colton Herta was the first of the Honda-powered cars on the speed charts with a 228.284mph. The IndyCar Classis winner continued his form from April's open test by quickly getting up to speed.
The 19-year old did bring out the caution period during the session after spinning on the pit exit of Turn 2 whilst trying to get up to speed in traffic, completely destroying a set of tyres in the process.
“All the big speeds came from big tows,” Power said.
“It's kind of hard to judge the true speeds of cars right now by themselves. You don't know what aero configuration people are running, whether they're doing qualifying sims or they're in race trim. We don't know where we stack up, honestly, as far as true speed.”
All the drivers except Carlin's Patricio O'Ward who were required to participate in the rookie orientation or refresher programs were able to do so, including Fernando Alonso in the #66 McLaren-Chevrolet.
The recently signed Red Bull junior driver suffered gearbox problems and was unable to pass his RoP, team-mate Max Chilton jumped in his car for the remainder of the day once it was fixed as O'Ward was not permitted onto the track.
The Mexican will be given time on Wednesday to complete his program.
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