The Citroën C4 and C6 models were designed to replace the Citroën Type A 10 hp and Citroën Type B model family cars. The styling of the two models was said to be heavily influenced by American counterparts of the same time period, however in France, the new model was considered just that: new.
The traditional grill styles of previous Citroën models were abandoned and a sleeker, flatter grill was used. There were numerous options in terms of body styles, including a particularly popular commercial line. These nameplates were later used for the Citroën C4 and the Citroën C6 in the 21st century; although being classified into a different class.
Sedan delivery and coupe utility vehicles were also produced under the Type AC4 index, in the basis of these vehicles, but were eventually replaced by the Citroen Type 23 trucks.

The Type AC 4 was launched in 1928 in the Paris Salon as was the six cylinder AC 6 both of which shared similar styling, albeit that the AC 6 had a longer bonnet than its four cylinder sibling.
In 1929, both vehicles were modified and renamed C4 and C6 and with a number of further modifications remained in production until 1932.
The AC 4 was
a very conventional design with an in-line four cylinder engine driving the rear
wheels via a three speed gearbox. Suspension was by leaf springs all around and
the front and rear drum brakes were Westinghouse servo assisted - a modern
feature in a twenties vintage car.


The engine of the Citroën AC 4 was a four cylinder 1628cc producing 30bhp at 3000rpm. This gave the car a top speed of approximately 80kph (around 50mph). With its worm and roller steering and servo assisted brakes this was a well-designed car of the twenties and was said to be excellent to drive.
The AC 4 Berline featured here was previously owned by the late Freddie Alles – an ardent collector of classic and vintage cars. The car was recently acquired by another collector / enthusiast of vintage and classic cars who prefers to remain anonymous.
Citroen AC 4
Technical Specifications
Production: 121,000
copies
Engine: 4 cylinders
Displacement: 1628 cm
3
Transmission: 3 speed
Gearbox, RWD
Brakes: Hydraulic
Servo assisted Drum Brakes all round
Unloaded weight: 1,175 to
1,245 kg
Maximum speed: More than 90
km/h
Length: 4 180 mm
Width: 1,580
mm
Height: 1,740
mm