LMDh (Le Mans Daytona h)[1] is a set of sports prototype regulations used alongside Le Mans Hypercar (LMH) in both the Grand Touring Prototype (GTP) class of the IMSA SportsCar Championship and the Hypercar class of the FIA World Endurance Championship.[2][3]
The LMDh ruleset was created jointly by the International Motor Sports Association (IMSA) and the Automobile Club de l'Ouest (ACO).[4] The cars serve as the successor to the Daytona Prototype International class, utilising regulations that were planned to become the next-generation Daytona Prototype International ruleset, converged with the Le Mans Hypercar ruleset.[5]
The FIA World Motor Sport Council had allowed LMDh cars to participate in the 2022 WEC season on a race-by-race basis, "to ensure the seamless introduction" in 2023; however, no LMDh cars would end up participating at any of the 2022 season races, and they would instead make their debut in the 2023 season.[6]