Chip Ganassi Racing teammates Kurt Busch and Kyle Larson led a pack of six Chevrolets in the top 10 during opening Cup Series practice at Dover.
Busch paced the 50-minute session with a lap of 168.445 mph (21.372 seconds). Busch’s lap was four miles an hour faster than the qualifying track record speed set by Brad Keselowski in 2014, which was 164.444 mph.
Larson’s best lap was 168.106 mph. Completing the top five was defending race winner Kevin Harvick at 167.950 mph (Ford), William Byron at 167.645 mph (Chevrolet), and Ryan Blaney also at 167.645 mph (Ford).
Filling out the top 10 were Alex Bowman at 167.512 mph (Chevrolet), Denny Hamlin at 167.496 mph (Toyota), Ricky Stenhouse Jr. at 167.170 mph (Ford), Chase Elliott at 167.162 mph (Chevrolet), and Jimmie Johnson at 167.069 mph (Chevrolet).
At 31st fastest Ryan Preece ran the most laps in practice with 29.
Four drivers lost 15 minutes of practice time. Ross Chastain, Chris Buescher, and Cody Ware were penalized because their cars were late to inspection at Talladega while Kurt Busch lost practice time because his car failed inspection multiple times last weekend.
UP NEXT: Qualifying at 3:35 p.m. ET.