The 1956 model was launched in September 1955. Independently adjustable separate front seats were made available at extra cost and at the same time the engine's compression ratio was increased from 6.73:1 to 7.5:1, lifting power by 3 horsepower to 93. Free-wheel was dropped and Laycock de Normanville electric overdrive made available. More sensitive power brakes were provided of a redesigned pattern. The recesses in the 'B' pillars that previously housed the trafficators in pre-1955 models were deleted in this update. Pleats were added to the seats, this treatment continued on subsequent P4 models.