The IMSA Prototype Challenge Presented by Mazda officials recently announced the 2018 schedule will adopt an endurance-racing format for the six-race season.

The IMSA Prototype Challenge will shift from its longtime “sprint race” format of two 45-minute races per event to a single 1-hour, 45-minute endurance race per weekend for both classes starting next season. Teams will have the option of using single- or two-driver lineups for each race.

No driver may compete in more than one race car per weekend. The qualifying driver must start the race on the tires used in qualifying, and each competing driver will be required to meet a 40-minute minimum drive time.

Each pit stop also will have a minimum time requirement, as team personnel and pit lane equipment will be limited.

As is currently the case in the IMSA Prototype Challenge, LMP3 and MPC class winners and podium finishers each will be recognized individually.

The six-race 2018 season begins the weekend of Jan. 5–7 on the revered 3.56-mile Daytona International Speedway road circuit as part of the annual Roar Before the Rolex 24 At Daytona.

For more information, including rules and specifications, visit the IMSA webpage here.