Josef Newgarden opened the Milwaukee IndyCar weekend by setting the pace in the opening practice session on the one-mile oval. The Sarah Fisher Hartman driver lapped in 22.0232 seconds at a speed of 165.916mph in his Dallara-Honda at what is the first of the short oval circuits visited by the series this year.
Helio Castroneves was 0.0863sec slower in his Penske-run Dallara-Chevrolet, the Chevy-powered machines being outnumbered 6-4 by their Japanese counterparts in the top 10.
KV's EJ Viso was third quickest, with Bryan Herta driver Alex Tagliani and Panther's JR Hildebrand rounding out the top five.
Last year's Milwaukee winner Dario Franchitti finished up just behind his Target Chip Ganassi Racing teammate Scott Dixon with the 11th-best time, while championship leader Will Power was 19th for Penske.