#42-Justin Marks was fastest during opening practice at Road America with a speed of 107.923mph.
The rest of the top 10: #48-Brennan Poole, #22-Austin Cindric, #7-Justin Allgaier, #62-Brendan Gaughan, #11-Blake Koch, #19-Matt Tifft, #00-Cole Custer, #24-Dylan Lupton, and #51-Jeremy Clements.
38 drivers practiced during the session.
See complete results on the Road America practice 1 speeds page (pdf).
