Jimmie Johnson was the fastest in the only Friday practice session for Cup Series teams at Auto Club Speedway in Fontana, California with a lap of 179.386 mph (40.137 seconds).
Johnson topped the 50-minute session over Austin Dillon, who ran a fast lap of 179.350 mph. Another Chevrolet driver, Chris Buescher, was third fastest with a lap of 178.975 mph. Buescher jumped up the leaderboard late in the session when he completed a run with some drafting help.
Rounding out the top five were Joe Gibbs Racing teammates Kyle Busch and Denny Hamlin. Busch ran 178.802 mph with Hamlin clocking in at 178.767 mph.
The rest of the top 10 were Brad Keselowski at 178.399 mph, Chase Elliott at 178.390 mph, William Byron at 178.108 mph, Matt DiBenedetto at 178.020 mph, and Kyle Larson at 177.686 mph.
Defending race winner Martin Truex Jr. was 16th fastest at 177.405 mph.
David Ragan, who was 15th fastest, and Joey Logano, who was 25th, ran the most laps in the session with eight.
There were no incidents.
UP NEXT: Qualifying at 5:10 p.m. ET.