Will Power topped the opening practice session for this weekend's IndyCar race at Mid-Ohio.
The Australian set the pace with a best lap of 1m06.8632, putting him 0.1581 seconds clear of closest rival Scott Dixon. Michael Andretti, Simon Pagenaud and Graham Rahal rounded out the top five.
Most teams arrived armed with information from last week's test, although Friday's warmer conditions and lower grip levels left several drivers feeling that their times were unrepresentative of their potential. Power is one of those who expects the track to evolve, but he said that getting a strong start to the weekend was important.
"The weather is going to change a lot over the next day or so," he said. "It was good to get a clean, fast lap and get confidence going into tomorrow."
The session was interrupted by a few cautions, including Alex Tagliani hitting the barriers at Turn 9 and Simona de Silvestro stopping on the track, but the latter was still encouraged by her first taste of the updated Lotus engine.
"We didn't test here when it was really grippy, so we're just taking it step by step," said the Swiss, who finished up 24th. "I think we've improved quite a bit. It was a good session."
Friday also marked the return of Giorgio Pantano, who has been subbed in to replace the injured Charlie Kimball at Ganassi.
"I have a good feeling about today," the single-seater veteran said. "I think in tomorrow's practice I'll be able to put myself more in the front."
Pos Driver Team/Car Time Gap 1. Will Power Penske Dallara-Chevy 1m06.8632s 2. Scott Dixon Ganassi Dallara-Honda 1m07.0213s + 0.1581s 3. Marco Andretti Andretti Dallara-Chevy 1m07.0644s + 0.2012s 4. Simon Pagenaud Schmidt Dallara-Honda 1m07.1063s + 0.2431s 5. Graham Rahal Ganassi Dallara-Honda 1m07.1088s + 0.2456s 6. James Jakes Coyne Dallara-Honda 1m07.2401s + 0.3769s 7. Josef Newgarden Panther Dallara-Honda 1m07.3133s + 0.4501s 8. Alex Tagliani Herta Dallara-Honda 1m07.3463s + 0.4831s 9. Dario Franchitti Ganassi Dallara-Honda 1m07.3574s + 0.4942s 10. Mike Conway Foyt Dallara-Honda 1m07.3899s + 0.5267s 11. Sebastien Bourdais Dragon Dallara-Chevy 1m07.4599s + 0.5967s 12. Oriol Servia Panther/DRR Dallara-Chevy 1m07.5207s + 0.6575s 13. JR Hildebrand Panther Dallara-Chevy 1m07.5361s + 0.6729s 14. Helio Castroneves Penske Dallara-Chevy 1m07.5518s + 0.6886s 15. Ryan Briscoe Penske Dallara-Chevy 1m07.5909s + 0.7277s 16. Ryan Hunter-Reay Andretti Dallara-Chevy 1m07.6638s + 0.8006s 17. James Hinchcliffe Andretti Dallara-Chevy 1m07.6766s + 0.8134s 18. Justin Wilson Coyne Dallara-Honda 1m07.7670s + 0.9038s 19. Takuma Sato Rahal Dallara-Honda 1m07.7677s + 0.9045s 20. Rubens Barrichello KV Dallara-Chevy 1m07.8628s + 0.9996s 21. EJ Viso KV Dallara-Chevy 1m07.9241s + 1.0609s 22. Tony Kanaan KV Dallara-Chevy 1m07.9520s + 1.0888s 23. Giorgio Pantano Ganassi Dallara-Honda 1m08.0753s + 1.2121s 24. Simona de Silvestro HVM Dallara-Lotus 1m08.4263s + 1.5631s 25. Ed Carpenter Carpenter Dallara-Chevy 1m08.9171s + 2.0539s