In January 1976 Mercedes-Benz introduced the 123 series saloon. It stepped out into the limelight for the first time with all the poise and assurance of being best in class. Classic body lines placed this new Mercedes-Benz in the tradition of its predecessor (W 115/114); they gave the new car modern elegance, a spirited but dignified look, and natural authority. This was no automotive revolutionary strutting out before the public, but a completely mature car of the upper mid-size category in which up-to-date technology and tried-and-tested engineering merged with the brand values. Much as expected, experts and customers alike gave the model a very warm welcome.
In various ways the design of the W 123 pointed towards the future: technically, with numerous innovations in the area of safety; and aesthetically, with a design that took its cue from the looks of the new S-Class W 116 and the current R/C 107 SL models. Expressions of this were the horizontally configured headlamps, for example, instead of the previous classic vertical lamps. The W 123 impressed with the high standard of its workmanship, its functionality, and its particularly wide range of body variants and engines. From 1977 this model series included the first production station wagon manufactured in-house by Mercedes-Benz.
Gains in safety and comfort
Greater safety, improved comfort and better serviceability: these were the demands made of the Mercedes-Benz design engineers when the specifications for the new model series were drawn up in 1968. Almost eight years later it was apparent that the experts from Stuttgart had accomplished their task in a convincing manner. It was precisely the high level of safety engineering and the mature overall design that secured this model the attention of the trade press and the customers from the very beginning.
The formulation of the specifications book laid the foundation for developing the future intermediate class model. In the years that followed, new design sketches were repeatedly thrown into the ring, demonstrating just how large the spectrum of possibilities for the design of the new Mercedes-Benz was: attempts at gentle renewal of the existing model series stood at one end of the spectrum of the studies; at the other, futuristic visions with sharp edges, roofs with huge overhangs at the back, steep rear windows and massive rubber bulges around the body. But the boldest designs remained in cold storage. By 1973 the shape of the W 123 was known for the most part. Preliminary prototypes were under way by 1974. The vehicle safety test series began with impact tests in the summer of 1974.
In developing the new model the design engineers set particular store on an even higher level of safety for the occupants. This was a topic of increasing debate in the 1970s and resulted in new regulations. On January 1, 1976, the Federal Republic of Germany made the wearing of seat belts for front seat passengers compulsory. In keeping with this trend, vehicle development focused on restraint systems and passenger compartments designed to minimise sources of injury. The engineers also considered integrating airbags, but these were not installed until 1982 as an optional extra in the W 123.
1975: Brilliant premiere
Perfect preparation was the slogan prior to the start of series production. For the first time at Mercedes-Benz a so-called pilot line was set up to build the W 123. On this training line, equipped similar to the future production facilities, workers practiced assembling the W 123. In all, 16 cars were produced there in summer 1975.
The meticulous preparation paid off, for the new model got a resounding reception from the public. Soon after presentation of the W 123 the first year's output was sold out; in 1976 young used cars of the series often fetched the price of a new car. Because of the long delivery times, among other reasons, Mercedes-Benz continued to build the "Stroke 8" for a whole year parallel to the new model. Taxi drivers, in particular, important customers in the intermediate range, had pressed for this offer.
Innovations and tried-and-tested technology
In technical terms the 123 series was an entirely new design, but was modelled both on its predecessor (W 115/114) and the new S-Class of 1972 (W 116). From the "Stroke 8" series the new model adopted in particular the engines, though with one exception: the newly designed 2.5-litre six-cylinder engine of the Mercedes-Benz 250 (M 123). Other features borrowed from the S-Class included the double-wishbone front suspension, in which the steering swivel axes of the wheels were aligned so that their imaginary extension coincided with the contact patch of the tyre on the roadway. This neutral setting (zero scrub radius) ensured that the wheels would not be deflected inwards or outwards during braking. The double-wishbone front suspension meant the elimination of the subframe, which had been introduced in the "Ponton" and presented the engine, transmission and front suspension as a unified whole. At the rear of the W 123 was a diagonal swing axle, which had proven its value in the W 115/114.
Occupant safety was served particularly by the combination of an even sturdier passenger compartment with large crumple zones: the front and rear ends of the vehicles were designed for controlled deformation in a collision to absorb appreciably more impact energy than was the case in earlier designs. The central section of the body, the so-called safety cell (patented in 1951 as "shape-retaining occupant compartment surrounded by energy absorbing zones at the front and rear"), had even more stability owing to the incorporation of stronger box sections in the roof frame and the six roof pillars. Stronger door beams ensured better impact protection.
The steering column of the 123 series was also optimised with a view to the driver's safety: a corrugated tube connected the jacket and the steering gear with each other. In an accident, the corrugated tube could buckle in different directions. This reduced the danger of the steering column penetrating into the passenger compartment (lance effect). This and the rigid passenger compartment with crumple zones were inventions of Béla Barényi, the pioneer of passive vehicle safety at Mercedes-Benz. Installation in the W 123 marked the premiere of the safety steering column, patented in 1963, as a complete system.
1976: Intermediate class with new face
When Mercedes-Benz put the new intermediate class saloon on the market in 1976, its place in the current Stuttgart model generation was recognisable at a single glance. Like the S-Class W 116 and the new SL of the 107 series, the W 123 had horizontal headlamps instead of the upright configuration of earlier days. The great majority of models illuminated the roadway with round headlamps in pairs behind a common rectangular lens. In 1976 this was the first hint of the "four-eyed" face of the 1995 E-Class (W 210) and its successor of 2002 (W 211). Only the top-of-the-range versions 280 and 280 E had rectangular halogen wide-band headlamps at the premiere of the W 123. In the 1982 facelift these rectangular lamps were then introduced for all versions and all body variants.
The lines of the saloon, from which the other body variants derived, impressed in 1976 by integrating up-to-date elements while paying regard to the established concept: draft designs during the planning period had put forward many variations for consideration, but neither the large roof-level rear spoilers nor the fastback concepts got beyond the drawing board. At the premiere of the new model the W 123 was offered not only as a saloon, but as a chassis too, in keeping with Mercedes-Benz tradition. Mainly Binz (Lorch) and Miesen (Bonn) built ambulances on this basis; hearses were created by Pollmann (Bremen), Rappold (Wülfrath), Stolle (Hanover) and Welsch (Mayen). The chassis with standard wheelbase (2.80 metres) was given the series number F 123 and were initially offered as the 240 D and 230. The extended chassis with a wheelbase of 3.43 metres (VF 123) was initially available for the 240 D, 300 D and 250.
Four or six cylinders?
The creators of the W 123 also fell back on proven technology for the engines. Solely the new 2.5-litre six-cylinder M 123 in model 250 (95 kW/129 hp) was newly developed for the premiere. The other eight models of the first year featured engines which had already powered the "Stroke 8": the in-line four-cylinder M 115 was used in the 200 (69 kW/94 hp) and 230 (80 kW/109 hp); the top-of-the-range 280 (115 kW/156 hp) and 280 E (130 kW/177 hp) models were amply powered by the M 110 in-line six-cylinder (as carburettor and injection engines). The diesel models 200 D (40 kW/55 hp), 220 D (44 kW/60 hp) and 240 D (48 kW/65) featured the four-cylinder engine OM 615; the 300 D model (59 kW/80 hp) was powered by the five-cylinder OM 617.
As early as 1978 Mercedes-Benz thoroughly revised this engine range. Up to the termination of the 123 series the power of the individual models increased owing to improved drive units. The 200 model (now with 80 kW/109 hp) even got a new engine, the M 102, in 1980. This engine was also fitted as an injection unit in the 100 kW (136 hp) 230 E model. An outstanding new power plant was the turbocharged five-cylinder diesel OM 617, which was included in the series in 1981 for the 300 D Turbodiesel model (92 kW/125 hp). In the United States this turbocharged compression-ignition engine was offered in all body variants; in Germany, however, the 300 D Turbodiesel model was available solely as a station wagon.
1977: Three new variants in one year
Enthusiasm for the W 123 increased further in 1977. This was the year in which Mercedes-Benz presented three additional body variants: the coupe, the long-wheelbase saloon, and for the first time in the brand's history a factory-built station wagon. By expanding its model range the brand forcefully demonstrated the versatility of the new model series. Compared with its predecessor, the coupe was much more independent in its design than the saloon. And the station wagon inaugurated an entirely new body variant in series production at Mercedes-Benz.
In March 1977 the coupe caused excitement at the International Motor Show in Geneva. Whereas the coupes of the "Stroke 8" series very closely followed the styling of the saloon, the new 230 C, 280 C and 280 CE models were distinctly more autonomous in character. Particularly the wheelbase, 8.5 centimetres shorter than that of the four-door version, in interplay with the lower roof and the sharply raked windscreen and backlight, gave the car a stockier, sportier look. The developers also improved the vehicle safety: a stiffened roof frame structure with high-strength roof pillars and reinforced doors resulted in an even sturdier safety passenger cell. The C 123 also profited fundamentally from the body design of the saloon, with its front and rear crumple zones designed for controlled deformability. The coupe also shared the suspension (diagonal swing rear axle and double-wishbone front suspension with zero scrub radius) and brake system with the four-door cars.
The appointments of the two-door versions were on a level with those of the top-of-the-range 280 and 280 E saloons. For all three coupe models this included wide-band headlamps, chromed air inlet grilles in front of the windscreen and chrome strips under the taillights. Accordingly, the facelift of September 1982 did not have as much of an impact on the coupes as it did on the saloons. After all, the coupes had always had the wide-band headlamps that were now introduced for all models. The new coupes were best recognised by the air inlet grilles in front of the windscreen, which were painted black from 1982 on.
Compression-ignition engine for the coupe
At production start-up there were three versions with petrol engine: the four-cylinder coupe from the 230 C model (80 kW/109 hp), and the two six-cylinder versions 280 C (115 kW/156 hp) and 280 CE models (130 kW/177 hp). A diesel-powered coupe, the 300 CD model (59 kW/80 hp), was added in autumn 1977, but this was produced exclusively for the US market. The diesel initiative in the elegant guise of the coupe pursued the aim of reducing the corporate average fuel economy (CAFE) of Mercedes-Benz automobiles in the North American market. CAFE describes the average fuel consumption of all models of a brand. The economical diesel engines permitted Mercedes-Benz to distinctly improve its CAFE score. When CAFE standards were further tightened, the 300 CD model was replaced in 1981 by the 300 CD Turbodiesel model. This coupe with its 92 kW (125 hp) output was not offered on the European market either, but superseded the 280 CE in the USA.
In 1980 the new 230 CE model replaced the 230 C coupe model. The 230 CE's M 102 engine with mechanically controlled petrol injection delivered 100 kW (136 hp). Mercedes-Benz also supplied the coupe with ABS as an optional extra, and – as of 1982 – with airbag. In August 1985 series production of the C 123 ceased. A total of 99,884 units of this model type were manufactured from 1977 to 1985, including 15,509 with diesel engine. In the first few months of its existence, particularly the long waits testified to customers' enthusiasm for the new coupe. Customers ordering in 1977 sometimes had to wait over two years for their cars.
1977: Long-wheelbase saloon
In August 1977 Mercedes-Benz introduced the long-wheelbase version of the intermediate class saloon: the wheelbase of the V 123 (3.43 metres) was 63 centimetres longer than that of the saloon (2.80 metres). That provided enough space for a third seat bench and made the car a comfortable taxi, company car or hotel limo for seven passengers. The 250, 240 D and 300 D models were offered with long wheelbase and had the same engines as in the W 123. Whereas the "tailfin" eight-seater saloon was limited to one very economical diesel engine (200 D long), the 123 series with three powerful versions of the long-wheelbase saloon followed the trend set by the "Stroke 8".
Despite its imposing proportions and powerful engines, the long-wheelbase saloon was not mainly intended as a representational vehicle. An indication of this was that the diesel engines were still in the majority as against the petrol engine of the 250 model. Rather, this body variant served as a sophisticated touring car for several passengers. Operating for hotels and trade fair companies and as a large-capacity taxi, the V 123 impressed with its high degree of ride comfort and great spaciousness. Many characteristics of this body variant were adopted by well-equipped vans.
1977: Station wagon model introduced at the Frankfurt Motor Show
A station wagon is a combination of passenger car and delivery van. Such vehicles have been available with the Mercedes star on the bonnet for several model generations. However, the cars were not built in Sindelfingen, but were the work of specialists: from 1953 on Lueg (Bochum) supplied the 170 V as a pack mule; in the late 1960s Binz (Lorch) even made a station wagon out of the sophisticated W 186. Versions of the "Ponton", the "Tailfin" and the "Stroke 8" followed (in each case by Binz and Miesen). In particular, the solutions for the W 115, which adopted the C-pillar without modification from the saloon, were considered questionable products of styling.
But these practical body variants with the large load space were not completely new to the Stuttgart engineers and designers. At first, under the name "Universal" Mercedes-Benz marketed the small "tailfin" as a station wagon model built by the Belgian manufacturer IMA. And the station wagon variant of the "Stroke 8", which had been developed to production standard, showed what an attractive load carrier should look like, even if in the end it was not manufactured in series. During the design phase of the W 123 there were still reservations about a station wagon as a fully-fledged member of the model family. The reason for this negative attitude was mainly to do with the reputation station wagons had at the time. The critics warned that this body type was too reminiscent of industry and the trades. They felt this was incompatible with the claim staked by a car in the Mercedes-Benz upper mid-range.
On the other hand, market research conducted during development of the concept for the 123 series showed there to be a definite demand for a sporty, luxurious five-door from quite a different segment of the market: the station wagon was well on its way to becoming a family and leisure car. The Board of Management realised this too and gave the go-ahead for the project in 1975. In the German market, though, the new Mercedes would not bear the typical German name for a station wagon, Kombi, and in 1975 the former designation Universal also failed to gain approval. At first the designation Stationswagen was considered meaning that instead of "250 K" or "250 U" the small six-cylinder variant with the load compartment would get the label "250 St" on the tailgate. Finally, it was decided that the suffix "T" should indicate the new variant, the letter standing for Tourism and Transport. The unusually high demand following its presentation at the Frankfurt International Motor Show (IAA) also suggested it stood for "Trend". Only the internal series designation still recalled the term Stationswagen: the station wagon model was coded S 123.
Station wagon: the sporty, elegant, spatial miracle
Series production of the station wagon commenced at the Bremen plant in April 1978. Technically the vehicle conformed to the saloon: drive system, brakes and suspension were identical, as were the exterior dimensions (length, width and wheelbase). But the rear end, with the high trailing edge of the roof and the low sill of the load compartment, made the new model variant a true spatial miracle. Even when the standard seats were occupied by the driver and as many as four passengers, the station wagon still offered 523 litres of space for loading up to the window line. And with the rear seat bench folded down, the load compartment capacity was 879 litres up to the window line. The concept additionally offered a number of options for flexible configuration of the interior. As an optional extra, the rear seat bench could be supplied with an asymmetric split. As required, one third or two thirds of the backrest could then be folded down. Additional folding seats facing the rear of the vehicle and stored in the load compartment floor were also available on demand. These features made for particularly flexible stowage space – appropriate for a well-appointed vehicle for family and sports, tourism and transport.
Automatic hydropneumatic level control made for a high degree of ride comfort irrespective of the load carried. This could be as much as 45 percent of the station wagon's kerb weight, which tipped the scales at 1500 kilograms. As an optional extra, the station wagon could be equipped with 15-inch wheels, alternative springs and shock absorbers, and a stronger brake booster, in which case the safe load capacity of the station wagon rose from the standard 560 kilograms to 700 kilograms. Further options included a child bench seat in the load area and chromed roof rails. The rails became standard equipment in the summer of 1978. All station wagon models were fitted with carpeting throughout, i.e. in the cargo area too. Unlike in the station wagons of other manufacturers, different materials were not used in order to distinguish between passenger and cargo areas.
The new body variant was initially offered as the 230 T, 250 T and 280 TE models, as well as the 240 TD and 300 TD. For all models light-alloy wheels were available as an optional extra, but only the 280 TE model had rectangular headlamps. The station wagon was built in Bremen. Only the models shown in Frankfurt and the first 100 vehicles of the series were produced in Sindelfingen. Seventy workers from the Bremen plant came to Sindelfingen for intensive training in the production of the new station wagon series, during which time 40 specialists from the parent plant of the W 123 put finishing touches to the production facilities for the station wagon in North Germany. Such painstaking preparations were largely responsible for the tributes that would later by heaped on the S 123 for its precision craftsmanship.
Turbodiesel premiere and facelift for the 123 series
During production of the W 123, the output of various models was improved on several occasions and new models were added. In 1980 the new M 102 engine superseded the old M 115; in the 200 model the new four-cylinder developed 80 kW (109 hp) as a carburettor engine; in the 230 E that replaced the old 230, the in-line four-cylinder – here fro the first time equipped with petrol injection – managed 100 kW (136 hp).
In October 1980 Mercedes-Benz presented a car with a turbocharged diesel engine for the first time in Germany. The 92 kW (125 hp) 300 TD Turbodiesel had the same engine as the 300 D Turbodiesel saloon and the 300 CD Turbodiesel coupe, both of which were built exclusively for the US market. At its 1980 launch, with a basic price of DM 37,200 the Turbodiesel was almost the most expensive production model of the 123 series. Only the 280 CE coupe model cost more (basic price DM 100 higher). Appropriately enough, the car with the turbocharged diesel power plant had the more upscale appointments, including rectangular wide-band headlamps and chromed air inlet grilles in front of the windscreen.
In September 1982 a previous distinguishing feature of the smaller models of the 123 series, the round twin headlamps, was discontinued. All models of the 123 series were equipped with the rectangular wide-band headlamps familiar from the 280 and 280 E models as part of an extensive model refinement package. The numerous other improvements included changed wind-deflecting mouldings on the A-pillars and power steering as standard.
Versatile: special versions of the 123 series
The W 123 often served as a basis for different bodies and conversions. For the purposes of the police, fire and rescue services there were modified saloons and station wagons. Companies like Binz and Miesen built ambulances on chassis. Other bodies and conversions – hearse, pickup, convertible, etc. – were created by outside bodybuilding firms. Finally, for taxi operation Mercedes-Benz offered the saloon, the station wagon and the long-wheelbase saloon ex factory with the appropriate specifications.
Various specially tuned versions of the 123 series were offered during its production life by companies like AMG, Brabus or Lorinser. The measures ranged from optical changes to the body with the help of paint, side skirts and various light-alloy wheels to modifications of the suspension for lowering the body, tauter damping, and camber changes on both axles. Other possibilities for sports-related improvement included optimisation programmes for production engines or the installation of more powerful engines.
The W 123 series and alternative drive systems
Mercedes-Benz began looking into alternative drive technologies at a very early stage. This purpose was repeatedly served by 123 series vehicles used by the engineers as test mules. In 1983 Mercedes-Benz presented a 280 TE with hydrogen drive. There was also a test vehicle with electric drive based on the station wagon. And from 1982 on there was even a 200 with bi-valent drive available as a production vehicle: the car operated on liquid gas or petrol, the driver choosing the mode by means of a switch.
From volume model to classic
Production of the saloon ceased in November 1985. As with the transition from "Stroke 8" to W 123, the new 124 series was built parallel to the old model for almost a year. Mercedes-Benz did not take the particularly successful station wagon models of the 123 series out of production until January 1986. Production of the 123 series ran from 1975 to 1986, with a total of just under 2.7 million vehicles being built. At 2,389,140 units, saloons made up the lion's share (2,375,440 saloons with standard wheelbase and 13,700 long-wheelbase saloons); but the new station wagon accounted for an impressive 199,517 units. The remainder was made up of 99,884 coupes, and finally 8,373 chassis for special-purpose bodies. Around 1,080,000 cars of the series were exported.
During ten years of production, the diesel-engined models proved the most successful: the top favourite among buyers was the 240 D model (448,986 saloons, 38,903 station wagons, 3841 long-wheelbase saloons and 1953 chassis for a total of 493,683 units). The most successful petrol-engined model was the 230 E model (245,588 saloons, 42,284 station wagons, 29,858 coupes and 294 chassis, giving a total of 318,024 units). Ranked according to body variants, the best-selling saloon was the 240 D model (448,986 units), the 230 TE model (42,284 units) proved to be the most popular station wagon, and among the coupe models the 280 CE (32,138 cars) took the honours. The 250 model led among the long-wheelbase saloons (5,180 units) and long-wheelbase chassis (2,888), the 240 D model among the chassis with standard wheelbase (794 units).
Many years after the end of production the 123 series was still a familiar sight on the roads. But today this generation of Mercedes-Benz upper mid-range has become something of a rarity and its models are rapidly establishing themselves as recent classics; the coupe, in particular, is one of the most coveted cars on the youngtimer scene.