the australian one and a half litre championship was a cams sanctioned national motor racing title contested annually from 1964 to 1968. it was open to drivers of cars complying with the australian 1½ litre formula which specified open wheel racing cars fitted with unsupercharged engines using commercially available fuel and limited to 1500cc capacity. the title was staged over a single race in the first two years and over a series of races in the last three.