The base, four-cylinder 180/190 and the
W105 six-cylinder 219
Ponton models looked very similar in appearance, from the rear doors forward, to the more luxury
W128 and
W180 stretched wheelbase six-cylinder 220a and 220 S(E) models. From behind, one could not easily differentiate even the top-of-the-line 220SE (E for 'Einspritzung', or fuel injection) from a base 180 model, but the longer bonnet (and wheelbase), and chrome touches identified it as an upscale, six-cylinder model. The 1951 to 1957
Mercedes-Benz 300 W186
Adenauer company flagship was a much larger car, with its own frame, body, interior, and engine. It was followed through 1962 by an updated limousine length
Mercedes-Benz 300d W189. The W120/W121 shared their
Ponton nickname with
other Mercedes models, drawn from their
ponton styling, a prominent design and styling trend regarded as resembling a
pontoon that unified a car's previously articulated hood, body, fenders and running boards into a singular envelope. The 180 and 190 four-cylinders were widely used as German taxis. Only these shorter Pontons featured low-wattage parking clearance lights at front bumper top rear. As in other Mercedes models, a simple toggle switch above the driver's left knee selected which side would illuminate, so as not to needlessly run down the battery, no small concern when restarting diesels in winter. Heater air intakes were on both sides of the radiator grille only on the W120/W121. The form and body of the car changed little during its production run. However, in 1957, a year after the introduction of the 190 saloon, the 180's M136 engine, which had originally been designed for the
Mercedes-Benz 170 Sb, was replaced with a downtuned version of the 190's M 121. The same year, the Mercedes star atop the faux external radiator cap was made spring-loaded to give when bumped: reports at the time indicated that this was either to pander to the requirements of certain export markets, notably
Switzerland, or to reduce the risk of pedestrian injury in the event of an accident. By 1959, the star was spring-retained on a ball base. A related two-door luxury roadster variant, the
W121 B II 190SL, was produced from 1955 to 1963. At the 1959
Frankfurt Motor Show, in time for the 1960 US model year, a slightly wider grille and slimmer taillights were introduced. The same wider grille was carried forward to the car's more flamboyantly styled
W110 "Fintail" successors, during 1961. At the time,
Studebaker-Packard had an agreement with
Mercedes-Benz to distribute their cars in the
US market. A prototype was built based on the W120 with Packard-styled headlights similar to those fitted on the
Packard Patrician. This prototype was called the
W122 but it never reached the production state; This was likely because the W120 platform that the prototype was based on was reaching the end of its life cycle, while the compact luxury sector was not that developed in the US market yet. == Technical description ==