The Oxford was updated for 1957 with a new fluted bonnet and small rear fins and an optional two-tone paint scheme all announced on 18 October 1956.

[5] Inside the bench seats trimmed in leather remained but the instrument cluster was revised and a new dished steering wheel fitted.

The engine now produced 55 hp (41 kW) following an increase in compression ratio though the top speed and acceleration remained the same.

A semi-automatic, two pedal, "Manumatic" transmission with centrifugal clutch with vacuum operation coupled to gear changes was optional.

The IV was introduced in 1957, announced by BMC with the Riley Two-Point-Six on 23 August 1957[8] and produced alongside the Series V until 1960.