The Brabham BT4 was designated as an 'International' racecar but in practice most such cars were used in the Australasian 'Tasman' series which was run to the rules of the 2500 cc Formula One until 1970. The 'International' cars used the Coventry Climax FPF 2500 cc engine. The engine bays of these cars had to be different from the BT3 Formula One car of that year, hence a distinct chassis designation.

This car was driven by Jack Brabham to a win at the 1963 Australian Grand Prix. The car then changed hands and was primarily raced by Denny Hulme in the 1964. After Hulme the car continued to be raced by Lex Davison in 1965.