Mercedes-Benz 190SL - World Of Classic Cars - Rank 51

The development of the 1955 Mercedes-Benz 190SL came about as a way to give everyday consumers a version of the powerful Mercedes-Benz 300SL. Unfortunately, in the opinion of many connoisseurs, it is not as well-regarded as its handsome and athletic older brother, and is not regarded as a real collectible.

Mercedes-Benz 190SL Convertible 1958

The general consensus is that the 190SL is underpowered and lacks performance. If it is compared with its stable-mate, the 300SL, or the 507, then the criticism is valid. The 356 had less power, but it was much lighter and far more nimble.
Perhaps the fault lies with Mercedes-Benz itself and its approach at the time of the little 190SL's introduction. In its styling and general concept, it was regarded as a sports car by the press and the public alike, but the company quietly promoted it as a sports tourer. There was not a lot of conviction in the tourer stance though, and at the car's introduction, the manufacturer talked quite openly of a version specifically for the race track.

Mercedes-Benz 190SL Roadster 1960

After the destruction of its Stuttgart factories during World War II, Daimler-Benz began its postwar reconstruction with limited production of the Mercedes Type 170 series sedan, complete with styling and a side-valve 1.7-liter four-cylinder engine that were strictly prewar. At the same time, postwar Germany desperately needed trucks and Daimler-Benz obliged.
The profits from these operations were plowed back into building new facilities, and in designing and developing important new models. While the prewar 170 was upgraded between 1946 and 1951, running in parallel was the development of a completely new range of luxury six-cylinder sedans and coupes. These appeared in 1951 as the 220 and 300, the engines of both models featuring a single chain-driven overheadcamshaft.

Mercedes-Benz 190SL Roadster 1961

With a successful prewar history on the racetracks of Europe with the all-conquering Silver Arrows, many Daimler-Benz engineers, particularly Rudolf Uhlenhaut, pushed for the company to re-enter motorsports. Formula 1 was out of the question -- the resources simply weren't available -- but developing a sports racing car using as many production components as possible from the new 300 series appealed to management.
Out of these discussions came the brilliant, but complex, 300SL. It was immediately successful, taking a fine second place to Ferrari in the 1952 Mille Miglia, victory in Bern, Switzerland, two weeks later, followed by outright victory at the grueling 24 hours at Le Mans.

Introduction of the 1955 Mercedes-Benz 190SL

The introduction of the 1955Mercedes-Benz 190SL was held in tandem with the debut of the more powerful 300SL, which overshadowed the 190SL almost from the beginning. The four-cylinder, two-seat sports car had a lot of solid qualities all its own, but just couldn't compete with its bigger sibling.
Mercedes-Benz's United States importer, Max Hoffman, an expatriate Austrian who became known as the "Baron of Park Avenue," wanted a production version of the 300SL to sell to his wealthy American clientele. But at the same time, he recognized the need for a less complex and more affordable sports car carrying the three-pointed star.

Mercedes-Benz 190SL Roadster 1955

His vision was of a sports car utilizing major components from the sedan range but wrapped in a svelte, stylish body. Hoffman would be successful with both requests, the 190SL and 300SL having their world premieres at the New York Motor Show on February 6, 1954.
Although the development and engineering for the 300SL came from Uhlenhaut's racing department, the 190SL was developed by technical director Fritz Nallinger's passenger car team. Nonetheless, both shared very similar styling cues, in particular the smooth roundness of their respective designs and the new grille.
The tall, imperious radiator topped with a three-pointed star was forsaken on the SLs for a far simpler, open design; a wide rectangular opening edged with chrome trim and a large star-in-a-circle within. The theme has been retained in various forms on the SL range ever since.

Mercedes-Benz 190SL Roadster 1958

By late 1951, the "Ponton" styling of the new W180 series 220 sedans was settled and production plans were well under way. Designers and engineers next began preparations during 1952 for the smaller W120 series 180 that would share a great deal of hardware with its big brother.
An offshoot of the W120 program was W121, which would become the 190SL. Early concepts of the 190SL were drawn in late September 1953 after the board had met earlier the same month with Hoffman in Stuttgart-Untertürkheim.
The 190SL's styling was developed by a small team under the direction of Karl Wilfert, Mercedes's chief stylist. While Friedrich Geiger designed the 300SL body, it was Walter Hacker and his people, including a young Paul Bracq (later to gain international recognition at BMW and Peugeot), who were responsible for the shape of the small sportwagen.

1955 Mercedes-Benz 190SL Design

The basic shape of the 1955Mercedes-Benz 190SL design was arrived at almost immediately. It featured headlights mounted at the leading edge of the front fenders, small strakes over the front wheel arch, a graceful curve up and over the rear fender to a sloping rear trunk, and, of course, the "open mouth" front air intake with the floating three-pointed star within.

Mercedes-Benz 190SL Roadster 1961

The 190SL sat on a 94.5-inch wheelbase, coincidentally the same as the 300SL, but was much leaner in its lines. Wheel tracks were 56.3 and 58.3 inches front and rear, respectively, and overall length was 166 inches. Body width was a wide 68.5 inches.
It was a prototype 190SL that was displayed at the 1954 New York Motor Show to gauge buyer interest. The reaction was positive and development, particularly of the body style, continued.
For its second premiere at the Geneva Salon in March 1955, many styling touches from the prototype were modified in preparation for series production. Detail changes included:

A redesigned hood with a smooth, full-length bulge replacing an ugly air scoop. Furthermore, the hood opening was shortened and hinged at the front.

The grille shape was more rounded.

Front fender profiles were altered slightly to raise their line into the doors.

Strakes were added over the rear wheel arches, matching those at the front (Mercedes publications referred to these styling elements as "splash shields").

Round front parking lights replaced rectangular units.

The fuel filler was shifted from the lower right rear corner under a flap to a normal locked cap protruding from the rear panel to the right of the license plate.

Mercedes-Benz scripts were removed from low down on the front fenders.

Inside, the dash was altered, too. The prototype's instrument binnacle was flat, shallow, and wide, with the minor gauges positioned between the speedometer and tachometer. For production, the binnacle projected slightly, was much taller and narrower, and the ancillary gauges relocated in a line below the two major dials.

Mercedes-Benz 190SL 1961

The dash top was extensively padded to reduce sun glare and increase occupant safety. (An early press photograph even showed the 190SL with a column gearshift lever.) A neat touch, and perhaps an indication of how Mercedes-Benz marketing folks really saw the 190SL, was the provision of two sets of heater controls -- one for the driver and another for the passenger. This required two heater matrixes under the hood and two sets of air trunks.

1955 Mercedes-Benz 190SL

Mechanically, the 1955 Mercedes-Benz 190SL was very advanced for the year of its introduction on the world market. Like the W180- and W186-series six-cylinder sedans, the 190SL's four-cylinder enginewould feature a single, chain-driven overhead camshaft operating staggered valves via pivoted long-and-short rocker arms. Designated M121, it shared nothing with its sedan counterpart's aged side-valve engine.

Mercedes-Benz 190SL Roadster 1962

The M121 engine was the first of a new four-cylinder engine family developed by the team led by Hans Scherenberg. Karl-Heinz Goschel is generally recognized as the key engineer in the development program.
Although the M121's cylinder-block material was cast iron and not aluminum alloy, as in the 300SL, the two did have 85mm cylinder bores in common. The stroke of the four-cylinder's forged three-bearing crankshaft was 83.6mm, giving a capacity of 1897cc. (Why the 88mm stroke of the six's crank was not retained to give a full 2.0-liter capacity has never been revealed.)
On a compression of 8.5:1 and with two side-draft, twin-choke Solex 44 PHH carburetors, Mercedes initially claimed 110 horsepower (125 SAE) at 5,500 rpm and maximum torque of 114 pound-feet at 4,000 rpm. By the time the 190SL went into series production, advertised power was reduced slightly to 105 bhp at 5,700 rpm and torque to 105 pound-feet at 3,200 rpm.

Mercedes-Benz 190SL Roadster 1961

Standing upright in the engine bay -- there wasn't room to lay it over as in the 300SL -- the under-hood view was highlighted by the cast aluminum plenum that channeled air from the circular air cleaner mounted on the bulkhead to the carbs. Tucked away under the carburetors was a four-into-one fabricated exhaust manifold; despite the overhead camshaft, the M121 engine's sophistication did not run to a cross-flow cylinder head.
The four-speed all-synchromesh gearbox was modified to accept a remote floor gearshift linkage. First prototypes were seen with a long, cranked lever that originated from well under the dash, but by production, this had given way to a neat central floor lever.
Suspension was, in the Mercedes-Benz tradition, independent all around. At the front were classic upper and lower wishbones with coil springs, while at the rear was D-B's famous single-pivot swing-axle. Coil springs were mounted on long trailing arms with rubber bushings to minimize noise transfer.

Mercedes-Benz 190SL Roadster 1961

Mounted horizontally above the differential was another coil spring that Mercedes referred to as a "compensating" spring designed to reduce camber variations during wheel movement. This low pivot-point system evolved out of Mercedes's 300SL racing program. The same system would appear on the 220 series sedans and, later, on the 190 sedans.
Braking also had a competition heritage. All four wheels carried finned aluminum nine-inch drums with steel liners. The front drums had twin-leading shoes, with leading-and-trailing shoes at the rear. An ATE Hydrovac booster was an option when production began, but from mid-1956 onward, it was fitted as standard.

Mercedes-Benz 190SL Roadster 1962

As on the new 220 sedans, the 190SL had a completely new self-supporting frame-floor system. It comprised a deep central tunnel, to accommodate the tail-shaft, flanked by rigid, welded box-section sills with a ribbed, pressed steel floor panel. The body panels were welded to this assembly.
Bolted to the front of this rigid frame was a demountable engine subframe. It attached at three points, all rubber insulated, and enabled the front suspension, steering, engine, and gearbox to be mounted as a unit on the assembly line, as well as facilitating simpler maintenance when the time came.