The Indianapolis 8 Hour is an endurance sports car race contested at Indianapolis Motor Speedway using the infield road course, first held in 2020,[1] making it the first ever endurance sports car race at this venue.

In 2022 the GT4 class was dropped; in addition the race ran into the twilight for the first time; and the GT World Challenge America entrants were awarded points at the full 8 hours rather than at the three-hour mark in previous years.

In 2022 14 cars took part in the IGTC within the total grid of 25 entries running GT World Challenge America.

The US leg of the SRO's IGTC - the California 8 Hours - was held at Laguna Seca circuit from 2016 to 2019.

[3] For 2022 the GT World Challenge America element of the event was extended such that the entire 8 hour duration scored points for the GTWC America entrants;[5] in previous years those entrants scored points for the first three hours only.