The W123 models surpassed their predecessor, the Mercedes-Benz W114, as the most successful Mercedes, selling 2.7 million units before production ended in the autumn of 1985 for the saloon/sedan versions and January 1986 for coupés and estates/station wagons.

[4] Following a slow production build-up during the first year, customers who placed their orders faced a lengthy waiting period of nine to twelve months.

Bruno Sacco defined the modern history of Mercedes-Benz, as he was responsible for the design of every Mercedes car, bus and truck for 25 years.

[8][9] Once the W123 reached the end of its service life, they were often shipped to Africa and third world countries where they were highly esteemed for their ability to travel on rough roads and to not require frequent maintenance.

The design is updated with styling cues from its larger sibling, Mercedes-Benz W116, namely wider ribbed taillights, horizontal headlamps, front turn signal indicators on the outer edge, and pull-to-open door handles.

If the optional air conditioning unit was ordered, a temperature roll dial was fitted to the row of control switches.

This setup is the same for North American models with the sealed beam units and glass plate partially covering the headlamp housing.

[11] The limousine was built on a stretched W123 saloon/sedan chassis with additional lower side panels behind the rear passenger doors.

The stretched limousine version was offered with complete front body clip (B-pillar forward) and strengthened chassis as the base for ambulances or hearses to be built by the conversion specialists such as Binz and Miesen.

[11] The world's first turbocharged diesel engine for a passenger vehicle, the OM617 A, was finally introduced in W123 models in September 1979, exclusive to the 300TD Turbodiesel for the European market.

One notable achievement was in the 28,200 km (17,500 mi)[16] 1977 London–Sydney Marathon road race, where the 280E won first and second, ahead of the third and fourth place Citroën CX.

The naturally aspirated 300TD was sold for two years (1979-1980) until the turbocharged 300TD Turbodiesel replaced it from autumn 1980 because consumers found the 300TD to be too heavy and too slow with the less powerful engine.

From 1981 until 1985, W123 models were sold only with diesel engines to comply with the federal regulation on corporate average fuel economy (CAFE) without paying heavy penalties.

[citation needed] Four-speed manual gearboxes were offered with four-cylinder inline engines (2.3-litre M115 petrol and 2.4-litre OM616 Diesel) only.

Customers could choose cloth, MB-Tex vinyl, velour or leather for the upholstery as well as interior wood trim for dashboard and centre console.

The driving dynamic enhancement options for extra cost became more extensive over the time: ABS (from August 1980 onward), self-locking differential gear, five-speed manual gearbox (introduced in 1982 for European markets only), Tempomat cruise control system, power steering system (standard from 1982 onward), passenger-side external rear view mirror (standard on S123 model), "Alpine" horn with selectable loudness (popular in Switzerland due to strict noise regulations), retractable steering column (from 1982 onward) and so forth.

For the first time in an executive saloon from Mercedes-Benz, the W123 had the option of fully automatic climate control at extra cost.

A rare option was a column gear selector that could be ordered with an automatic gearbox if the customer wished.

In the estate/station wagon model, a third row rear-facing foldable seat was offered as an extra cost option.

A new five-speed manual gearbox was introduced in February 1982 and was available in all models except those with the 3-litre turbocharged diesel engine but not in North America.