Busch, again driving the No. 18 Toyota, was the fastest in the XFINITY Series first practice session for Saturday’s Treatmyclot.com 300 at the Auto Club Speedway.
Busch finished first practice with a speed of 177.327 mph, considerably faster than his JGR teammate, Erik Jones, who was second quickest at 174.982 mph. Busch only made two laps in the opening session. Jones made 21 laps.
Rounding out the top 10 were Kyle Larson, Elliott Sadler, Austin Dillon, Ryan Blaney, Daniel Suarez, Ryan Reed, Ty Dillon, and #7 Justin Allgaier.
Justin Allgaier will have to go to a backup car after he slid up into the wall during practice.