Kyle Larson put up a fast time early and held the advantage throughout the first practice session for the Gander Outdoors 400 at Dover International Speedway. He set the pace with a lap of 164.444 mph.
Chase Elliott was the fastest Chevrolet driver with a lap of 163.236 mph in fourth.
Last week’s winner Ryan Blaney (162.719) rounded out the top five.
The fastest Toyota belonged to Denny Hamlin. He had the seventh best speed of 162.690 mph.
Bubba Wallace (18) posted the most laps.