#23-Spencer Gallagher was fastest during opening practice at Michigan International Speedway with a speed of 190.305mph.
The rest of the top 10: #16-Ryan Reed, #22-Brad Keselowski, #18-Kyle Busch, #1-Elliott Sadler, #48-Brennan Poole, #9-William Byron, #00-Cole Custer, #20-Denny Hamlin, and #33-Brandon Jones.
All 40 drivers practiced during the session.
See complete results on the Michigan practice 1 speeds page (pdf).
