1951 Citroen Traction Avant
The Citroën Traction Avant (French pronunciation: [tʁaksjɔ̃ aˈvɑ̃]) is an automobile which was produced by the French manufacturer Citroën from 1934 to 1957. About 760,000 units were produced.
The Traction Avant, French for "front wheel drive", was designed by André Lefèbvre and Flaminio Bertoni in late 1933 / early 1934. While not the first production front wheel drive car – Alvis built the 1928 FWD in the UK, Cord produced the L29 from 1929 to 1932 in the United States and DKW the F1 in 1931 in Germany – it was the world's first front-wheel drive steel monocoque production car. Along with DKW's 1930s models, the Traction successfully pioneered front-wheel drive on the European mass car market.
The Traction Avant's structure was a welded monocoque (unitized body). Most other cars of the era were based on a separate frame (chassis) onto which the non-structural body ("coachwork") was built. Monocoque construction (also called Unit Body or "Unibody" in the US today) results in a lighter vehicle, and is now used for virtually all car construction, although body-on-frame construction remains suitable for larger vehicles such as trucks.