At the 2018 24 Hours of Le Mans, the initial details of the new top class for the FIA World Endurance Championship were announced at the ACO's annual press conference, with the regulations set to be active for 5 seasons. Numerous aspects of the design for the new class would be kept open, with a free engine architecture and the freedom to run any number of cylinders with the choice of a turbocharged or naturally aspirated design. The cars would have an overall weight of with a controlled weight distribution, alongside a defined maximum fuel flow, with controlled efficiency and other regulations to control developmental costs. Hybrid systems would feature an electric motor mounted on the front axle with a fixed performance of , giving the cars a four-wheel drive layout, while the engine's maximum performance target would be set at . Each car would have two seats, a larger cockpit than current LMP1 cars, a wider windscreen, and a roofline more consistent with road cars. Manufacturers would be required to make their hybrid systems available for privateer teams to lease at a cost cap, while any manufacturer or company would be able to design and build its own hybrid system, which would undergo homologation by the FIA and ACO. The cars would also be slower than their predecessors, with a target lap time of 3:20.