GT3 cars are set of regulations maintained by the FIA for grand tourer racing cars designed for use in various series throughout the world.

GT3 cars must be based on mass production road cars. The cars in GT3 are designed to have a weight between 1200kg and 1300kg with horsepower between 500 hp and 600 hp.

24H SERIES has featured cars such as Aston Martin AMR GT3, Audi R8 LMS GT3, Dodge Viper GT3-R, Ferrari 488 GT3, Lamborghini Huracán GT3, McLaren 720S GT3, Mercedes-AMG GT3, Bentley Continental GT3, Nissan GT-R Nismo GT3, Porsche 911 GT3 R.

Group GTX, exceptional cars, is a group of cars which is added to accept a wider variety of cars. The cars in GTX have a guide line of approx. 2,5-3,4 kg/hp (faster than GT4 and slower than GT3). Balance of performance will be applied on all cars to ensure that this is a competive but fair class.

24H SERIES has featured cars in the GTX class such as BMW M3 F80, Brokernet Silver Sting, KTM X-BOW GTX (X16), Lamborghini Huracán Super Trofeo, Lotus Exige V6 Cup R, MARC II V8, Porsche 911 Cup MR, Vortex 1.0.

The Porsche new 911 GT3 (992) models are high-performance homologation models of the Porsche 911 sports car. The cars are according to the regulations of the Porsche Carrera Cup.

The Porsche 911 GT3 models are high-performance homologation models of the Porsche 911 sports car.

The cars are according to the regulations of the Porsche Carrera Cup Deutschland.

Eligible models in the 991 class:

• Porsche 911 GT3 Cup (991 Gen I)
• Porsche 911 GT3 Cup (991 Gen II)

*Not a stand alone class anymore in 2023, all 991 cars will be applicable in the GTX class

In the GT4 class, the specific GT4 regulations are applicable. Same as GT3 cars, these cars must be based on mass production road cars.

24H SERIES has featured cars such as Aston Martin Vantage AMR GT4, Audi R8 LMS GT4, BMW M4 GT4, McLaren 570S GT4, Mercedes-AMG GT4, Porsche 718 Cayman GT4 CS MR.

A TCR Touring Car is a TCR-homologated car and and based on 4 or 5 door production cars, and are powered by 2.0 litre turbocharged engines. The balance of performance is according to the latest TCR BOP for Endurance Events.

24H SERIES has featured cars such as Audi RS3 LMS TCR, Cupra TCR, Honda Civic Type R TCR, Hyundai i30 N TCR, Opel Astra TCR, Peugeot 308 TCR, Volkswagen Golf GTi TCR.

Group TCX, exceptional cars, is a class generally meant for special Touring cars and some GT-cars, with approximately the performance of TCR cars. The cars in TCX class have a guide line of approx. 3,5-4,0 kg/hp. The BOP will be applied in a way to make it possible for both TCR and TCX to have the change for the overall victory in the TCE-Division.

24H SERIES has featured cars such as BMW 240i, BMW M2 CS Racing, BMW M240i Racing Cup, BMW M4 GTR, Ginetta G55, KTM X-BOW, Lamera Cup, Ligier JS2 R, Lotus Elise Cup PB-R, Porsche 718 Cayman GT4 CS, Seat Leon Cup Racer V1 DSG.

The performance guideline of the TC class is: Cars that are slower than class TCR and TCX. As a guideline, the following cars are eligible:

• Touring cars up to 2000cc and supercharged up to 1600cc
• BMW 240i Racing Cup (only if the car is acc. BMW Cup Regulations)

24H SERIES has featured cars such as BMW 335i Coupe, BMW E46 M3, BMW M2 CS Racing, BMW M240i Racing Cup, BMW M3, Honda Civic Si, Honda FK8-Civic Type-R, Peugeot 308 Racing Cup, Peugeot RCZ, Renault Clio Cup IV, Seat Leon Supercopa MK2.