Mercedes W123 (1976-1986): the indestructible Mercedes

A saloon, then a whole family

The four-door saloon, code W123, led the way and would remain by far the most-produced version, with around 2.4 million built. It was joined in 1977 by the C123 coupé, lower, with no central pillar, and with its wheelbase shortened by 85 mm. In 1978 came the estate, which Mercedes calls "T" and whose internal code is S123. It was assembled in Bremen, and the very last W123s would roll out from there.

Two more niche versions complete the range:

• the V123, a saloon with a wheelbase stretched by 63 cm, with three rows of seats. Taxis, hotels and companies adopted it to carry seven or eight people;
• the F123, a long chassis delivered without rear bodywork, on which specialist coachbuilders such as Binz or Miesen built ambulances and hearses.

The engines: from taxi Diesel to fuel-injected six-cylinder

The designations follow the Mercedes tradition of the time: the number gives the displacement, the "D" signals a Diesel and the "E" petrol injection. The catalogue is wide, from the 2-litre four-cylinder to the 2.7-litre six-cylinder.

The petrols

At the bottom, the four-cylinder 200 and 230; above, the 250 and its 2.5-litre six-cylinder. The top of the range goes to the 280 and 280 E, powered by the M110 twin-overhead-cam six-cylinder of 2,746 cm³, carburettor or injection, which reaches 185 hp in its final version. In June 1980, a new four-cylinder, the M102, replaced the old engine in the 200 and 230, the latter becoming the fuel-injected 230 E.

The Diesels

This is where the W123 forged its reputation. The range starts with the four-cylinder 200 D, 220 D and 240 D, whose first versions top out at around fifty horsepower, and continues with the 3-litre five-cylinder of the 300 D. These engines are no powerhouses, but they seem impossible to wear out. German taxis made them their tool of the trade, and passing 500,000 km without major work was nothing exceptional.

Presented in September 1979 and built from 1980, the 300 TD Turbodiesel estate pushes the five-cylinder to 125 hp thanks to a turbocharger. On the W123, this turbocharged engine was also offered in saloon and coupé form, but only for export, to the United States in particular. In Europe, it remained reserved for the estate.

The W123's robustness was also proven in competition. In 1977, a barely modified 280 E won the London-Sydney marathon rally, an event lasting several weeks across Europe, Asia and Australia. For Mercedes, absent from competition for many years, it was a high-profile comeback.

Safety before gadgets

The W123 is nothing spectacular at first sight, but its body was designed to protect its occupants. The passenger compartment forms a rigid cell, reinforced at the roof and pillars, while the front and rear deform to absorb the energy of an impact. The doors receive reinforcements against side impacts, and the steering column is connected to the steering box by a corrugated tube designed to collapse, to stop it moving back towards the driver in an accident.

The electronic equipment arrived during its career and as an option, at high prices: ABS from 1980, then the driver's airbag in autumn 1982, paired with a seat belt pretensioner on the passenger side. A 1976 W123 therefore has neither: beware of adverts that promise equipment that is impossible for the year.

Three series for one silhouette

The W123 evolved through small changes. Enthusiasts tell three series apart:

• First series, until summer 1979: round headlights on most versions, with rectangular headlights reserved for the 280 and 280 E and the coupés;
• Second series, from August 1979 to August 1982: smaller steering wheel, new controls, revised upholstery;
• Third series, from September 1982: rectangular headlights and power steering as standard on all versions, black ventilation grilles in front of the windscreen.

These pointers are useful when ordering parts: lights, trim and controls change from one series to another, and a car may have received parts from a later series over the course of repairs.

The end of the career and the successor

At the end of 1984, Mercedes presented the W124, which gradually took over. W123 saloons and coupés left the lines in 1985, and the last estates rolled out of the Bremen plant in January 1986. The final tally was 2,696,915 units, all body styles combined.

One note on vocabulary, to finish: you often read that the W123 is the first "E-Class". The name did not exist at the time. It only appeared in July 1993, when Mercedes reorganised its range into Classes and renamed the facelifted W124. The W123 is the ancestor of the E-Class, not an E-Class.

Driving a W123 today: what to watch for

The W123's mechanicals largely live up to their reputation, provided they have been maintained. The weak points are rather to be found in the bodywork and the components that age with time:

• Corrosion: sills, wheel arches, floors and door bottoms deserve careful inspection, because build quality does not prevent rust. Tired body seals let water in.
• Running gear: bushes, ball joints and shock absorbers have often lived several lives on these high-mileage cars. See the running gear and suspension parts.
• Brakes: discs, pads and hoses are found in the W123 brakes section.
• Routine maintenance: a W123 Diesel lives a long time if it gets regular oil changes and clean filters. See the filters and the engine parts.

Before ordering anything, identify your model precisely using the table of Mercedes W123 engines: model type and engine code are detailed there for each version. And if your W123 spends the winter in the garage, our tips on winterising a classic car properly will help you find it in good shape in spring.

Nearly fifty years after its launch, the W123 remains one of the easiest classics to live with day to day. Robust, simple to maintain, comfortable: it never needed to try too hard to win people over.