The Mini Cooper S with a 1,275 cc engine was introduced in 1964.
BMC added the 1,275 cc Cooper S to the Mini range in April 1964. It used the enlarged version of the A-series four-cylinder engine and was developed alongside a 970 cc Cooper S. The 970 cc car helped BMC compete in under-1,000 cc racing classes, while the 1,275 cc version delivered stronger performance.
The new engine was not the first Cooper S. The high-performance model had debuted in 1963 with a 1,071 cc engine, larger brakes and competition-oriented tuning. The 1,275 cc model therefore represented an expansion of the Cooper S range rather than its original launch.
The 1,275 cc Cooper S became the best-known classic performance Mini. Cooper S cars helped establish the Mini’s racing reputation and won the Monte Carlo Rally in 1964, 1965 and 1967. Production of the 1,275 cc Cooper S continued until 1971, when it was discontinued in the United Kingdom and eventually replaced in the sporting range by the less powerful Mini 1275 GT.