Auto Club Speedway has traditionally been a mighty test of horsepower and willpower for Xfinity Series regulars, but this season, in particular, there are a few reasons to believe that a 17-year string of Cup winners in the Xfinity race there may be stopped.

Fulltime Xfinity drivers Michael Annett started the year with a victory at Daytona and Christopher Bell answered at Atlanta – the first time a season has opened with back-to-back Xfinity Series regulars winning since 2012 when James Buescher won the Daytona season-opener and Elliott Sadler won the next week at Phoenix.

In particular – and with good timing – a pair of California drivers are leading the way in the series. Defending Xfinity Series champion Tyler Reddick, of Corning, Calif., leads the championship by four-points over Christopher Bell heading into Saturday’s Production Alliance Group 300 (at 5 pm ET on FS1, MRN, SiriusXM NASCAR Radio).

Reddick has two top-five and three top-ten finishes in the opening four races and has led the third-most laps (75) this season. A second championship would make him the first to earn back-to-back titles since Ricky Stenhouse Jr. in 2011-12.

Fellow Californian Cole Custer, of Ladera Ranch, finished runner-up to Reddick in the 2018 Xfinity Series Championship and trails his rival by only 11 points heading to their ‘home’ track. As with the Richard Childress Racing driver Reddick, Custer has a pair of top-fives and three top-tens through the opening four races with a best effort of runner-up to in Atlanta.

The Stewart-Haas Racing driver has the second best average finish this season (7.2) and a top-ten (sixth place in 2018) in two previous Xfinity starts at Auto Club Speedway.

The field will undoubtedly face a major challenge from Toyota driver Kyle Busch who begins the first of his two opportunities to score a historic 200th NASCAR national series win in this Saturday race. Busch leads all drivers with six previous wins in the Xfinity race at Auto Club Speedway.