[1][2] The T81 was designed ahead of the 1966 World Championship season to operate within the new 3 litre engine regulations that came into effect that year.

These were supplied by the Chipstead Group, Maserati's UK distributors, who had taken control of Cooper in April 1965.

In fact the car was Cooper's first monocoque chassis, although by this time such an arrangement had already become standard in Formula 1, having been pioneered by the Lotus 25 four years earlier.

Jochen Rindt and Richie Ginther were the works drivers, qualifying in seventh and ninth position respectively.

However John Surtees, who had replaced Ginther after walking out on Ferrari, took the car's first win in the final race of the 1966 season in Mexico, and in turn Surtees's replacement, Pedro Rodríguez, won the very next race, the 1967 season opener in South Africa.