Two years later came the larger L20, with a six-cylinder variant of the company's module engine which had been introduced in the late 1930s.

At the end of 1949, Scania-Vabis introduced a direct injected diesel development of their module engine.

It had been designed in collaboration with British truck manufacturer Leyland Motors.

In 1951 the old fashioned non-synchro four-speed gear box was replaced by a synchronized five-speed transmission.

In the spring of 1954, the final development of Scania-Vabis’ six-cylinder module engines was introduced, with larger displacement.