 They group cars into three categories with specific engine sizes; less than one litre, less than two litres, and over two litres.Hillclimbs, sprint races and smaller races expanded the championship, which now had about 15 races per season.The famous races like Le Mans still counted towards the prototype championship, however, the points valuation wasn't very tabular so the FIA returned to the original form of the championship with about 6 to 10 races.