IndyCar takes hybrid testing to its marquee venue in Indianapolis

INDIANAPOLIS (AP) — Indianapolis Motor Speedway reverted to its original purpose Thursday — serving as a test track for new automobile technology.

The lessons learned about IndyCar's new hybrid cars could reverberate throughout next season.

Four drivers, including reigning series champ Alex Palou, spent Thursday turning laps on the 2.5-mile Brickyard in race cars equipped with paddles or buttons used to store or deploy extra energy while cars are on the track.

The early reviews were mixed.