What Is the O’Reilly Auto Parts Series?
The NASCAR O’Reilly Auto Parts Series is NASCAR’s second-tier national touring series. It carried the Xfinity Series name through 2025 and adopted the O’Reilly Auto Parts title in 2026.
The series combines full-time championship teams, developing drivers, veteran series regulars and event-specific entries. A driver can compete for more than one organization during a season, so Grand National Today stores team/car assignments separately rather than forcing one team onto a driver’s entire year.