The Austin Mini-Cooper S with 1071 cc capacity had been on sale since March 1963 and it was joined by a further Cooper S model with a capacity of 1275 cc in spring 1964. The 1275 Series model had been developed as the basis of homologation for the 1300 cc class in international rally sport. Acceleration to 100 km/h in less than 11 seconds and a top speed of nearly 160 km/h (with variations depending on the ratio) meant that the most powerful Cooper S achieved the performance of a full-blooded sports car. The car achieved three overall victories in the Monte Carlo Rally in 1964, 1965 and 1967. It became the darling of the public and emerged as the epitome of the Cooper S.