Production of the model now known as the Defender began in 1983 as the Land Rover 110, a name which reflected the 110-inch (2,800 mm) length of the wheelbase. The Land Rover 90, with 93-inch (2,362 mm) wheelbase, and Land Rover 127, with 127-inch (3,226 mm) wheelbase, soon followed.

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Superficially there is little to distinguish the post-1983 vehicles from the Series III Land Rover. A full-length bonnet, revised grille, plus the fitting of wheel arch extensions to cover wider-track axles are the most noticeable changes. Initially the conservative engineering department insisted that the Land Rover was also available with a part-time 4WD system familiar to derivatives produced since 1949. However, the part-time system failed to sell and was quickly dropped from the options list by 1984. While the engine and other body panels carried over from the Series III, mechanically the 90 and 110 were modernised.