M143

When the W 143 took over from the W 21 in 1937 it inherited the older car's 2.2-liter six, now working through a conventional four-speed gearbox rather than the effective overdrive top of its predecessor. What it gained was breadth: two wheelbases, and bodywork running from two- and four-door saloons through Cabriolets A, B and D to Pullman-Limousines, landaulets and six-seat Tourenwagen. More than 20,000 were built by 1941, which made this quiet six one of the busiest engines in the pre-war range.

It had a harder-working life too. For the government's motor-vehicle winter test of 1938 — staged as a sporting contest, intended as a covert assessment of how ordinary German cars would serve in war — Daimler-Benz built the 230 SV, a two-seat sports car on the short 2,700 mm wheelbase with magnesium-alloy bodywork and aluminum wings. Thirty-three were made that year, their M143 given higher compression and 58 PS. In 1939 the same car returned as the 230 S, by which time the engine had been rebored and renamed M153.