The class was an amalgamation of the previous Australian Formula 2 and Australian Formula 3 categories, using the same or newly developed cars, but powered by production-based single-cam, 2 valve per cylinder engines, with an engine capacity between 1100 cc and 1600 cc. Popular engines initially included the Toyota 2T, Ford Kent and Holden Gemini. Later on the Volkswagen Golf became the engine of choice due to its lighter weight and greater power levels. Initially the new format proved to be very successful, attracting the largest grids seen in Australian formula racing for years. The manufacture of cars in Australia for the formula flourished. It wasn't uncommon to see cars designed and built by the same person that drove them.