#33- Brandon Jones was fastest during opening practice at Chicago with a speed of 174.413mph. The rest of the top 10: #20-Erik Jones, #19-Matt Tifft, #22-Ryan Blaney, #62-Brendan Gaughan, #2-Austin Dillon, #1-Elliott Sadler, #9-William Byron, #18-Daniel Suarez, and #3-Ty Dillon.
35 drivers practiced during the session.
See complete results on the Chicago practice 1 speeds page (pdf).
