four years. Unusual in Europe at the time were the wide, 90° opening rear doors. Also unusual were the windows in the rear doors that lowered fully, despite the intrusion the wheel arch into the door frame. Engine The 403 used an enlarged version of the Peugeot 203's 1290 cc petrol engine. Displacing 1468 cc, the straight-four unit employed pushrod-actuated valves and hemispherical combustion chambers and a crossflow cylinder head to produce at about 4,900 rpm and of torque at 2,500 rpm. Power increased to in 1958. An unusual feature at the time was the thermostatically controlled engine fan which cut out when the engine temperature fell to 75°C and reengaged when the engine temperature increased to 84°C. Claimed advantages included an improvement in fuel consumption of between 5% and 10% according to average speed and the avoidance, under many conditions, of fan noise. A small hot water-activated heating device for the carburetor linked to the heater for the passenger cabin — operating only when the driver activated the cabin heat, but not when the ambient temperature was high enough for the heater to be left off. A diesel powered Peugeot 403 estate was introduced in the Autumn of 1958, the first of a long line, followed by a diesel saloon a year later. After the 203's discontinuation in 1960, a version of its 1290 cc powerplant became available as an option on a reduced specification version of the 403, branded initially as the "403 Sept" ("7") and soon afterwards as the "403 Berline Luxe". Car tax in France was mostly based on engine size, and the smaller engined 403 fell within the 7CV taxation class rather than the 8CV of the bigger version. Transmission The 403 used a manual 4-speed all-synchromesh transmission driving the rear wheels. The gear change lever stuck out from the right side of the steering column. For the Paris Motor Show in October 1957 the manufacturer offered, at extra cost, an electro-magnetic Jaeger automatic clutch, activated when changing gear. Interior The front seats reclined, allowing their seat backs to be flush with the cushions of the rear seat, creating a "couchette". Body variants The wheelbase was lengthened by for the five door Peugeot 403 "Familiale" and "Commerciale" estate versions. The Familiale provided a third row of seats and was described as a 7/8 seater while the Commerciale offered a more conventional seat configuration for an