A more powerful Mini Cooper, dubbed the “S“, was developed in tandem and released in 1963. Featuring a 1071 cc engine and larger servo-assisted disc brakes, 4,030 Cooper S cars were produced and sold until the model was updated in August 1964. Cooper also produced two models specifically for circuit racing, rated at 970 cc and a 1275 cc, both of which were also offered to the public. The smaller-engine model was not well received, and only 963 had been built when the model was discontinued in 1965. The 1275 cc Cooper S models continued in production until 1971.
Sales of the Mini Cooper were as follows: 64,000 Mark I Coopers with 997 cc or 998 cc engines; 19,000 Mark I Cooper S with 970 cc, 1071 cc or 1275 cc engines; 16,000 Mark II Coopers with 998 cc engines; 6,300 Mark II Cooper S with 1275 cc engines. There were no Mark III Coopers and just 1,570 Mark III Cooper S’s. The Mini Cooper S earned acclaim with Monte Carlo Rally victories in 1964, 1965 and 1967. Minis were initially placed first, second and third in the 1966 rally as well, but were disqualified after a controversial decision by the French judges. The disqualification related to the use of a variable resistance headlamp dimming circuit in place of a dual-filament lamp.
It should be noted that the Citroën DS that was eventually awarded first place had illegal white headlamps but escaped disqualification. The driver of the Citroën, Pauli Toivonen, was reluctant to accept the trophy and vowed that he would never race for Citroën again. BMC probably received more publicity from the disqualification than they would have gained from a victory – but had the Mini not been disqualified, it would have been the only car in history to be placed in the top three on the Monte Carlo for six consecutive years.