The T81 was the first Cooper entirely designed by Derrick White. Equipped with the Maserati V12 60 ° engine that gave about 360 horsepower, the T81 was initially built in five units and debuted in 1966 showing a certain competitiveness. John Surtees won in Mexico in 1966, the first Cooper victory since 1962. In 1967 the engine was updated and a modified version was presented, called T81B. The T81 / T81B were entered in their last races in 1968.