#42-Kyle Larson was fastest during opening practice at Dover International Speedway with a speed of 154.540mph.
The rest of the top 10: #19-Matt Tifft, #22-Ryan Blaney, #18-Daniel Suarez, #1-Elliott Sadler, #7-Justin Allgaier, #00-Cole Custer, #33-Brandon Jones, #48-Brennan Poole, and #2-Austin Dillon.
39 drivers practiced during the session.
#23-Spencer Gallagher and #52-Joey Gase wrecked in turn 3. Both teams will need a backup.
See complete results on the Dover practice 1 speeds page (pdf).
