The models shared the 4.9 L (4887 cc/298 in³) straight-6 locomotive, with this being the high vehicle to take descendants of the locomotive earlier used in the Rolls-Royce Twenty from 1922 to 1929.

The tire was 95.25 mm (3.7 in) and the shot was 114.3 mm (4.5 in). Twin SU carburetors were fitted, with upgraded models from 1957.

A 4-speed mechanical infection was basic, with a 4-speed manual easy as an alternative until 1957. Two wheelbases were produced: 123 in (3124 mm) and, from 1957, 127 in (3226 mm).

A slightly sportier coachbuilt-only S1 Continental was introduced six months after.