The Mercedes-Benz W110 and the six-cylinder W111 were the first series of Mercedes cars to be extensively crash tested for occupant safety.

The "D" denoted a Diesel engine, a technology pioneered by Mercedes-Benz and championed despite widespread derision in the motoring press.

[citation needed] The body was derived from the W111 series but with a 145 mm shorter nose and round headlights (which gave a front-end appearance more reminiscent of the W120/121 "Ponton" models).

The interior layout and dimensions were also identical to the W111 220b, but with fewer options such as fixed-back seats and bakelite trim on the dashboard (as opposed to wood in the W111 models).

Because the 190c and 190Dc models were basically a W111 220b with a shorter front, they offered the same interior and luggage space as the W111 series but with smaller and more fuel efficient engines.

An estate version of the 230S four-cylinder-engined car was introduced in 1965 and achieved modest success in certain markets including Germany, Belgium and the UK.