BUYERS GUIDE
Top of the Line – W186, W188 & W189 Sedans, Coupes & Cabriolets • 1951-1962
The discrete, desirable and largely handbuilt Mercedes-Benz 300 series was a true top-of-the-market successor to the company’s storied ‘Grand Mercedes’ vehicles of the 1930s
Article: Richard Simonds, Gary Anderson
Data Tables: Daniel Stahl
Images: Maurice lIang • Daimler Archives
With German industry in shambles at the end of World War II, the management of Daimler-Benz aspired to regain the glory of the 1930s, when Mercedes-Benz vehicles were at the forefront of elegance and engineering. To achieve this lofty goal, the firm planned and executed a multi-pronged strategy to rebuild its enviable prewar strength and reputation. The company first built basic 170 utility vehicles and small sedans to replenish financial reserves before using that foundation to create an extraordinary series of sedans, coupes and cabriolets to reclaim its position as a world leader in luxury.
The return of elegance
At the Frankfurt Auto Show in April 1951, Daimler-Benz introduced a limited range of four-door sedans built around the company’s new 3-liter engine – vehicles thus designated as 300s. These stately machines offered tall grilles and voluptuous curves that recalled the automobiles of the late 1930s and early 1940s.
The 300 offered a 6-cylinder engine with overhead cam and two carburetors, 4-speed column-shifted manual transmission, and load-leveling rear axle, plus a massive X-frame, 12-volt electrical system and a central lubrication for the front suspension. Beautiful interiors rich with wood, Wilton carpets and high-quality fabric or leather upholstery created a sense of traditional luxury. The fledgling Federal Republic of Germany soon adopted a stretched version of the 300 as a state vehicle for the country’s first chancellor, Konrad Adenauer: The spacious interior allowed him to wear his top hat in the car – giving the 300 its enduring nickname, the “Adenauer.”
The 300b added a brake booster, front-door vent windows, two double-barreled carburetors and higher compression for more power. The 300c received a Borg-Warner automatic transmission and a larger rear window in 1955. In 1957, the 300d was completely restyled, had a longer wheelbase and a fuel-injected engine.
The Adenauer was available as both sedan and cabriolet. The cabriolet offered a soft top with Landau bars that folded back but did not fully retract to the body line. The rearview mirror was on a shaft that could be pivoted up to see above the convertible top when it was folded down. Though popular as parade cars for dignitaries, only a very small number of these four-door cabriolets were built.
The 300 sedans also were the basis for development of one of Mercedes-Benz’s most famous models, the 300SL Gullwing. By June 1951, believing its reputation would benefit from a return to international motorsports in Grand Prix and sports-car racing, management undertook the development of a racecar based on the block and head of the 300 engine. The 2,996cc engine block was canted at 45-degrees to fit in the low, space-frame body of the 300SL. Transmission, suspension components, and many interior elements were lifted straight from the parts’ bin of the 300-series sedans. The W194 300SLs – in coupe, roadster, and open-wheel form – would capture victory after victory all over the world, underlining the superiority of German engineering and reliability.
Adding sporty performance
The final prong of the company’s reputation-rebuilding strategy was introduced at the Paris Motor Show in October 1951. The 300S was a two-door grand touring automobile with coupe, cabriolet and roadster styles. This new range targeted entertainment celebrities and wealthy trendsetters just beginning to show off their affluence in postwar Europe and America; it was available only by custom order. Designated as the W188 with a wheelbase nearly six inches shorter than the Adenauer, this automobile used the 300 head and block, but with three carburetors, producing 150 horsepower. The 300Sc of 1956-1957 added chrome accents and a fuel-injected engine.
All three body styles were sketched by Hermann Ahrens, designer of the grand prewar 540Ks. Rather than drawing on the futuristic aero style popularized by American designers, Ahrens echoed key features of the 540Ks – a tall proud grille topped with the Mercedes star, curvaceous front fenders and a long hood line with short rear deck to visually thrust the car forward with a sense of presence and class. The 300S and 300Sc cabriolets were similar to the four-door 300 cabriolets. The 300S and 300Sc roadster had a fully retracting soft top that fit under a taut tonneau cover level with the body.
The interiors of these impressive two-door vehicles displayed meticulous design, fabrication and assembly. Wood veneer in a rich variety of grains and finishes was available, and soft trim was of the finest leather and woven wool. Luxury details included rear seats that folded down for luggage and a rear-view mirror that, like that of the 300d cabriolet, could be pivoted upward for visibility over the folded cabriolet top. A Grundig or Becker Nürnberg radio was standard, complete with two large speakers mounted in the foot wells. A set of fitted leather luggage for the trunk was available, as well as a set that fitted behind the front seats. Although many owners requested the fitted trunk luggage, the interior set is extraordinarily rare.
The impressive trio of personal luxury two-door models on the Paris show stand excited the crowds. Orders quickly flooded in; production was at capacity through 1952 and 1953. However, demand for such perfection wasn’t infinite, even in the burgeoning economies of the 1950s. Only 92 examples of the exclusive 300S left the Sindelfingen coachworks in 1954-1955. The revamped 300Sc appeared in 1956-1957 before the series was canceled.
When new, the sedans cost more than the famed 300SLs and the two-door models. However, the latter cars today command substantially more than the four-door sedans and cabriolets.
Given the styling and engine choices that were available to luxury buyers in the United States, Mercedes-Benz had to make changes in its luxury models. After all, a customer could buy a longer, lower, wider Cadillac or Lincoln with a V-8 engine, automatic transmission and air-conditioning for half the price of a top-of-the-line Mercedes-Benz sedan. Still, with their traditional elegance, the 300s were often purchased by wealthy people who did not want the ostentation that came with a Rolls Royce, Cadillac or Lincoln.
Reasons to buy a 300-series
Any of the 300s offer grand touring in luxury, elegance and style, often earning thumbs-ups from other drivers when cruising down the highway. Exclusiveness means the driver will be noticed – particularly in the four-door cabriolet and two-door models – when arriving at a car show.
Both two-door and four-door vehicles are very durable, with design features that were unusual for their time, such as a front lubrication system, rear load-leveling mechanism, four-wheel independent suspension and a 12v electrical system.
Sedans offer room for six occupants (with three in front) or room for five in luxury. The coupes, cabriolets, and roadsters are quite comfortable for four occupants. Every model in the 300 range offers grand touring with classic luxury, elegance and style.
Reasons not to buy a 300 series
If the car in question has not been well maintained, it can become a money pit. Replacement parts are difficult to find due to the low volume of original production. Restoration can be very expensive and exceed market value.
These automobiles offer very leisurely performance – even for the 1950s. In traffic, the heavy clutch and manual transmission can make driving laborious. The Borg-Warner automatic transmission does not match the torque curves of the engine and is expensive to repair; it can be replaced by a more modern transmission if total originality is not a concern.
Checkpoints
Keep in mind that these cars are about 60-70 years old, and were assembled to order and produced only in limited numbers. Finding a completely original example is very important. Each unit was essentially hand-made; coupes, cabriolets and roadsters were custom-built and hand finished to a very high level of perfection. Consequently, body parts are not directly interchangeable.
Structurally, the biggest risk for the potential purchaser is rust that can be found in the box frame of the body-on-frame construction and around headlights, door drains and doorsills. A practical buyer should think carefully before undertaking an extensive restoration of one of these imposing cars; costs can quickly exceed market value many times over. Such a heroic effort may be worthwhile as a labor of love, but as an investment, it rarely pays off.
Carburetors are prone to warping and internal corrosion; balancing the two- and three-carburetor models is as much an art as it is science, and best done by someone with experience. Fuel-injection systems are subject to fuel deposits that make the vehicle run rough – or not at all. This is true of all cars with carburetors or fuel injection when they are not used regularly.
Electrical systems on unrestored cars likely will need replacement wiring and new relays and switches. Interior parts can be very expensive and difficult to find. Original tube-type radios are costly to replace, but can be rebuilt for a fee.
Suspension components are not readily available and expensive to replace or rebuild. If not lubricated regularly, the grease hardens and can cause suspension breakage.
Finally
Despite the complexity of these rare vehicles and the multiple challenges to restoring and maintaining them properly, W186, W188 and W189 300s change hands at very high prices, although significantly lower than the sports cars that share the same basic engine. Buyers who are able to afford one of these marvelous machines – and those of us who cannot – can not help but admire these fine automobiles that played such a key historic role in Mercedes-Benz regaining its reputation and status in the 1950s.
1952 W186 300 Sedan
1958 W188 II 300Sc Roadster
1958 W188 II 300Sc Coupe
1958 W188 II 300Sc Cabriolet
1958 W186 300c Cabriolet D
German Chancellor Konrad Adenauer (in office 1949-1963) used a 300 limousine; this example is on display at the national museum of German history in Bonn, the Haus der Geschichte.
Chronology
1951 April 300 (W186) 4-door sedan revealed at first postwar Frankfurt international Auto Show
1951 October 300S (W188) 2-door introduced as roadster, cabriolet and coupe at Paris Motor Show
1951 November 300 sedan production starts, with 4-speed transmission (most column shift), two single-barrel carburetors, rear load levelers, front suspension lubrication, low-compression engines (6.4:1 for poor postwar fuels)
1952 March 300 cabriolet added
1952 June 300S cabriolet production starts
1952 August 300S coupe production starts
1952 September 300S roadster production starts
1954 March Recirculating-ball steering replaces worm steering in all models
1954 April 300 sedan and cabriolet production ends
1954 May 300b sedan introduced, higher compression engines (7.4:1),
two double-barrel carburetors, brake booster, front vent windows,
rear door wind deflectors; 300b cabriolet added
1955 June 300S roadster production ends
1955 July 300S cabriolet production ends
1955 August 300b sedan, 300S coupe production ends
1955 September 300c production starts as improved sedan with larger rear window, available Borg-Warner 3-speed automatic transmission, larger tires
1955 December 300c cabriolet added. 300Sc coupe cabriolet, roadster production starts with chrome trim around the wheel arches & side of engine, and fuel-injection (“Einspritzmotor”) badge on rear bumper
1956 May 300c with 4 inch longer wheelbase introduced
1956 June s300c cabriolet production ends
1957 July 300c sedan production ends – all versions
1957 August 300d sedan is a redesign with 4-inch-longer wheelbase of 300c, pillarless hardtop construction, larger trunk, more vertical front and rear fenders and taillights, fuel injection, higher-compression ratio engine, and a Borg-Warner 3-speed automatic transmission; manual transmission optional
1958 April 300Sc coupe, cabriolet and roadster production ends
1958 July 300d cabriolet production starts
1958 December Optional Behr air conditioning offered for 300d, a first for Mercedes-Benz
1962 February 300d cabriolet production ends
1962 March 300d sedan production ends
Notes: Most 300c and nearly all 300d models sold in the United States had automatic transmissions. All postwar Mercedes-Benz engines have hardened valve seats and valves, allowing them to be operated with unleaded fuel. The 300, 300b and 300c can be operated on regular fuel; the higher-compression 300d requires premium fuel.
MODEL YEARS CHASSIS ENGINE POWER (DIN hp) TORQUE (DIN lb-ft)
300 Sedan 1951-1954 186.000 2,996cc I6 115 at 4,600 145 at 2,500
Cabriolet D 1952-1954 186.014
300S Coupe 1952-195 188.011 2,996cc I6 150 at 5,000 170 at 3,800
Cabriolet A 1952-1955 188.000
Roadster 1952-1955 188.012
300b Sedan 1954-1955 186.011 2,996cc I6 125 at 4,500 163 at 2,600
Cabriolet D 1954-1955 186.014
300c Sedan 1955-1957 186.016 2,996cc I6 125 at 4,500 163 at 2,600
Cabriolet D 1955-1956 186.033
300Sc Coupe 1955-1958 188.014 2,996cc I6 175 at 5,400 188 at 4,300
Cabriolet A 1956-1957 188.013
Roadster 1956-1958 188.015
300d Sedan 1957-1962 189.010 2,996cc 160 at 5,300 175 at 4,200
Cabriolet D 1958-1962 189.033
MODEL TRANSMISSION 0-62 MPH TOP SPEED MPG (US)
300 Sedan M-4 18 sec. 96 14.3
Cabriolet D
300S Coupe M-4 15 sec. 109 13.8
Cabriolet A
Roadster
300b Sedan M-4 17 sec. 99 14.7
Cabriolet D
300c Sedan A-3 • M-4 17-18 sec. 96-99 13.8-14.7
Cabriolet D
300Sc Coupe M-4 14 sec. 112 13.8
Cabriolet A
Roadster
300d Sedan A-3 • M-4 17-18 sec. 103-106 13-13.8
Cabriolet D
Production Totals
YEARS MODEL TOTAL BUILT
1951-1954 300 Sedan • Cabriolet 4,927
1951-1955 300S Coupe • Cabriolet • Roadster 560
1954-1955 300b Sedan • Cabriolet 1,878
1955-1957 300c Sedan • Cabriolet 1,483
1955-1958 300Sc Coupe • Cabriolet • Roadster 20