Larson led the single-lap average speed with 162.705 mph and set the mark early in the 50-minute session.
Statistically, Dover is one of Larson’s best tracks with five top-five and eight top-10 finishes in 11 career starts. He finished third in this year’s spring race.
Martin Truex Jr. ended up second (161.377 mph) and Kevin Harvick third (160.385 mph). Brad Keselowski and last weekend’s winner, Chase Elliott, rounded out the top-five.
Completing the top-10 speeds were Matt DiBenedetto, Ricky Stenhouse Jr., Chris Buescher, Austin Dillon and Kurt Busch.
Larson also had the fastest average speed (157.752 mph) among all drivers who ran at least 10 consecutive laps. Jimmie Johnson and Alex Bowman were second and third, respectively, in that category.