#32-Kyle Larson was fastest during opening practice at Chicagoland Speedway with a speed of 177.055mph. #99-Alex Bowman was second, followed by: #31-Justin Allgaier, #54-Kyle Busch, #3-Austin Dillon, #5-Brad Sweet, #22-Joey Logano, #12-Sam Hornish, Jr, #7-Regan Smith, and #20-Brian Vickers. 42 drivers practiced during the session. See complete results on the Chicago practice 1 speeds page (pdf) .
