Helio Castroneves set out his bid for a fifth Indianapolis 500 pole position by setting the best lap of the month so far in the Pole Day morning practice session.
The Penske driver produced a lap of 39.5181 seconds at an average speed of 227.744mph early in the two-hour practice, which saw the field split into two groups for half an hour of running each before all cars were allowed to take to the track for the final hour.
Chevrolet-powered cars filled the top three positions, with Ana Beatriz second in Andretti Autosport and Conquest Racing's joint entry, followed by Castroneves' team-mate Ryan Briscoe.
Honda's leading contenders were Dario Franchitti (Ganassi) and consistently impressive rookie Josef Newgarden (Sarah Fisher Hartman) in sixth, split by Andretti driver James Hinchcliffe.
Qualifying begins at 11am local time, with positions 10 to 24 set during the first five hours of running. The fastest nine drivers then return to the track to shoot for pole position.
Pos Driver Team/Car Time Gap
1. Helio Castroneves Penske DW12-Chevy 39.5181s
2. Ana Beatriz Andretti/Conquest DW12-Chevy 39.7901s + 0.2720s
3. Ryan Briscoe Penske DW12-Chevy 39.9914s + 0.3002s
4. Dario Franchitti Ganassi DW12-Honda 39.8640s + 0.3321s
5. James Hinchcliffe Andretti DW12-Chevy 39.8611s + 0.3430s
6. Josef Newgarden Fisher DW12-Honda 39.8796s + 0.3615s
7. JR Hildebrand Panther DW12-Chevy 39.9141s + 0.3960s
8. Graham Rahal Ganassi DW12-Honda 39.9309s + 0.4128s
9. Wade Cunningham Foyt DW12-Honda 39.9337s + 0.4156s
10. Will Power Penske DW12-Chevy 39.9354s + 0.4173s
11. Sebastian Saavedra AFS/Andretti DW12-Chevy 39.9450s + 0.4269s
12. Tony Kanaan KV DW12-Chevy 39.9533s + 0.4352s
13. EJ Viso KV DW12-Chevy 40.0454s + 0.5273s
14. Charlie Kimball Ganassi DW12-Honda 40.1054s + 0.5873s
15. Alex Tagliani Herta DW12-Honda 40.1150s + 0.5969s
16. Scott Dixon Ganassi DW12-Honda 40.1400s + 0.6219s
17. Bryan Clauson Fisher DW12-Honda 40.1403s + 0.6222s
18. Ed Carpenter Carpenter DW12-Chevy 40.1661s + 0.6480s
19. Rubens Barrichello KV DW12-Chevy 40.1670s + 0.6489s
20. James Jakes Dale Coyne DW12-Honda 40.1734s + 0.6553s
21. Mike Conway Foyt DW12-Honda 40.1762s + 0.6581s
22. Sebastien Bourdais Dragon DW12-Chevy 40.1814s + 0.6633s
23. Takuma Sato Rahal DW12-Honda 40.2380s + 0.7199s
24. Katherine Legge Dragon DW12-Chevy 40.2684s + 0.7503s
25. Michel Jourdain Jr Rahal DW12-Honda 40.3716s + 0.8535s
26. Townsend Bell Schmidt DW12-Honda 40.4197s + 0.9016s
27. Oriol Servia Panther/DRR DW12-Chevy 40.5192s + 1.0011s
28. Simon Pagenaud Schmidt DW12-Honda 40.6647s + 1.1466s
29. Justin Wilson Dale Coyne DW12-Honda 40.6655s + 1.1474s
30. Simona de Silvestro HVM DW12-Lotus 41.8724s + 2.3543s