IMSA will mandate four and three-driver lineups for all WeatherTech SportsCar Championship classes in the Rolex 24 at Daytona and six-hour races, respectively, beginning in 2025, it has been revealed.
Additionally, three-driver lineups will now become mandatory across the field for the Mobil 1 Twelve Hours of Sebring and Motul Petit Le Mans from next year.
Confirmed in the publication of next year’s sporting regulations, IMSA will require the GTP and GTD Pro classes to follow the same protocol that’s been in place for the Pro-Am-enforced LMP2 and GTD classes in the Michelin Endurance Cup rounds.
Previously, GTP and GTD Pro teams had the option of running one less driver in those races, with entrants taking split approaches, particularly at Daytona and most opting not to use three drivers at the Sahlen’s Six Hours of The Glen.
While the rule for the Rolex 24 and six-hour races will not come into effect until 2025, GTP and GTD Pro teams will need to run with three-driver lineups in the ten and 12-hour enduros at Michelin Raceway Road Atlanta and Sebring International Raceway, respectively, beginning next year.
Although not mandatory until now, three-driver lineups in GTP and GTD Pro for those races have been commonplace.
The 2025 WeatherTech Championship season, meanwhile, is expected to have two six-hour races on its calendar, with Watkins Glen being joined by the newly lengthened six-hour Battle on the Bricks at Indianapolis Motor Speedway.
Minor changes have been made to the 177-page sporting regulations document that will be in effect for the 2024 season, meanwhile.
In addition to clarifications of testing regulations, particularly with tire usage, IMSA has clarified that LMP2 and GTD Pro/GTD teams are not be allowed to change tires during qualifying sessions.
This came into question during qualifying at last month’s Motul Petit Le Mans, which saw mixed conditions. The regulation now states that teams “must use only dry or wet tires.”
Additionally, teams will now only be permitted a maximum of one change of class within a category per season, subject to the sole discretion of IMSA.
This rule is directly in reference to GTD Pro and GTD, which saw several teams switch classes multiple times over the course of the 2023 season.
For the one permitted change, a team representative must given written notice of the change request to IMSA’s electronic registration system by no later than the event entry deadline, while it’s prohibited to change class without the express permission of the sanctioning body.
IMSA has also increased the penalties for full season teams not participating in all events, stating that entrants are subject to “penalty and fines” for missing races in addition to still being responsible for all season-long entry fees.
This comes amid the sanctioning body’s oversubscribed entry list for the 2024 season, which was released during last month’s season-ending Petit Le Mans. A reserve list has been established, although not published, by the series.