Mercedes-Benz 300 SL

The Mercedes-Benz 300 SL (chassis code W 198) is a two-seat sports car that was produced by Mercedes-Benz from 1954 to 1957 as a gullwinged coupé and from 1957 to 1963 as a roadster. The 300 SL traces its origins to the company's 1952 racing car, the W194, and was equipped with a mechanical direct fuel-injection system that increased the power output of its three-liter overhead camshaft straight-six engine.

The 300 SL was capable of reaching 260 km/h (162 mph), earning it a reputation as a sports car racing champion and making it the fastest production car of its time. The car's iconic gullwing doors and innovative lightweight tubular-frame construction were groundbreaking.

The designation "SL" is an abbreviation of the German term , meaning "super-light", a reference to the car's racing-bred lightweight construction. The 300 SL was introduced to the American market at the suggestion of Max Hoffman, Mercedes-Benz's United States importer at the time, who recognized the potential demand for a high-performance sports car among American buyers. The Mercedes-Benz 300 SL remains a highly sought-after classic car and is celebrated for its performance, design, and technological advancements.

Development

Origin in the W194 racing car

The 300 SL traces its origin to an endurance racer, the Mercedes-Benz W194, developed by Daimler-Benz in 1951. It used the 3-liter inline-6 M186 engine, shared by the company flagship 300 "Adenauer" saloon (W186) and the two-seat 300 S grand tourer (W188).

Although W194's engine produced less power than competing cars by Ferrari and Jaguar, its low weight and low aerodynamic drag made the W194 fast enough to be competitive in endurance races.

Mercedes-Benz developed a new version for the 1953 racing season by replacing the M186's carburetors with mechanical direct fuel-injection, and shifting to 16-inch wheels; the gearbox was installed on its rear axle. Its body was made of Elektron, a magnesium alloy, which reduced its weight by . Mercedes-Benz decided not to race this alloy car, choosing instead to begin participating in Formula One in 1954. Later versions revised the body to lower air resistance, and did not continue the transmission arrangement.

Origin of the 300 SL

The idea of Mercedes producing a toned-down Grand Prix car targeted to affluent performance enthusiasts in the booming post-war American market was suggested by the company's U.S. importer, Max Hoffman, at a 1953 directors' meeting in Stuttgart. Mercedes' new general director, Fritz Konecke, agreed to Hoffman's order for 1,000 cars to guarantee the success of the production run; after Hoffman placed an initial order for 1,000 to support their production. The roadster was DM 32,500 in Germany, and $10,950 in the US – 10 percent more expensive than the coupé in Europe, and over 70 percent more in the US.

{| class="wikitable" style="text-align:center; width:50em"

!| Option|| Price (USD)

|Color (other than metallic silver)||65

|Bumper guards (4)||40

|Windscreen washers||18

|Becker radio||264

|Leather upholstery (coupé)||165

|Fitted luggage (roadster)||85

|Crated shipment from factory||80

|Competition springs (4)||88

|Competition front shock absorbers (2) ||41

|Competition rear shock absorbers (2) || 85

|Competition camshaft||73

|Rudge wheels (5) ||350

|Optional ring and pinion gears, per set||80

|Hardtop for roadster|| 178

SL abbreviation

thumb|1955 Mercedes-Benz 300SL Gullwing

Mercedes-Benz did not announce what the abbreviation "SL" meant when the car was introduced; magazines and company officials have called it "Sport Leicht" and "Super Leicht" ("light"). It was called "Sport Leicht" on the company website until 2017, when "SL" was changed to "Super Leicht" after a chance finding in the corporate archives.

300 SLS

thumb|The 1957 [[Sports Car Club of America championship-winning 300 SLS was a 300 SL roadster modified to meet its racing standards.]]

A special 300 SLS (Super Light Special) version of the 300 SL roadster was created for the Mercedes-Benz US racing team to compete on the Sports Car Club of America (SCCA) national circuit in 1957. After the 300 SL coupé dominated the D Production class en route to titles in 1955 and 1956, the rules were changed to make the class more competitive by enlarging the maximum engine size from 3 to 3.5 liters. Rather than radically modifying its engine size (on the cusp of releasing the company's new 300 SL roadster, replacing the coupé), Mercedes-Benz created two roadsters to campaign on the D Modified class SCAA circuit. They featured a solid cover over the passenger seat, a low-profile racing screen in place of a full-width and -height windscreen, a driver's seat roll bar, a custom cowl with engine air intake, and no front and rear bumpers. These and other modifications lowered vehicle weight from to . Engine output was increased , to . Team driver Paul O'Shea again won the title for the company.

Overview

thumb|alt=A black coupé with its bonnet, both doors, and boot open|The coupé’s unusually high and wide door threshold led to the adaptation of its signature [[gullwing doors.]]

The 300 SL has a steel tubular frame chassis, with a steel body combined with an aluminum bonnet, doors, dashboard, and boot lid to further reduce weight. An additional could be eliminated with an expensive all-aluminum body, but only 29 were made. Storage space for luggage is behind the seats in the coupé; the boot only holds a spare wheel and fuel tank. The roadster was available with two custom-fitted leather suitcases for the larger boot. The coupé's windows are fixed and roll down in the roadster.

Exterior

The body consists mainly of sheet steel, with the bonnet, boot lid, dashboard, sill, and door skins made of aluminum. Silver-grey was the standard color; all others were options.

The objective of the overall design was to make the vehicle as streamlined as possible. The width of the tubular frame along the cockpit allowed the cabin roofline to be inset considerably on both sides, dramatically reducing the front area. The structure was also quite high between the wheels, prohibiting the attachment of standard doors. The only option – already used on the W194 race car – which would allow passengers over its high, deep sill was a gullwing door.

The car’s distinctive eyebrows are a functional feature in the front, both physically and aerodynamically deflecting road water from the windscreen, and stylistic in the rear, added for visual symmetry.

Engine

The Mercedes-Benz M198 engine is a water-cooled overhead cam straight six. Like the racing Mercedes-Benz M194, the 300 SL borrowed the basic two-valves-per-cylinder M186 engine from the regular four-door 300 (W186 "Adenauer") luxury touring car introduced in 1951. Compression was set at 8.55:1. The result was aerodynamic efficiency and an enormous, sand-cast aluminum intake manifold as wide as the engine.

The engine was coupled by a single-disc dry clutch to a four-speed transmission with gear ratios of 3.34:1, 1.97:1, 1.39:1, and 1:1, and a reverse ratio of 2.73:1. From March 1963 to the end of production later that year, a light alloy engine block was installed in 209 vehicles.

Chassis

thumb|alt=See caption|The 300 SL's [[space frame|tubular frame]]

Like modern racing cars, the 300 SL has a tubular frame, designed by Mercedes head engineer Rudolf Uhlenhaut and made of chrome-molybdenum steel. Such a frame provided high rigidity with low mass. Thin straight tubes were assembled as triangles, with the finished frame weighing a remarkable . Elements of the coupé frame fill span the entire width of the vehicle’s track from wheel to wheel, making for an unusually high and deep threshold for access to the passenger compartment. The upper tube is so high it is level with the driver's elbow,

Suspension

The 300 SL's 4-wheel independent suspension was borrowed heavily from the regular Mercedes-Benz W186 "Adenauer" luxury tourer, given a sportier tuning. Front-to-rear weight distribution is almost exactly in the center of the vehicle.

The front suspension consists of unequal-length double wishbones, coil springs, hydraulic telescopic shock absorbers, and an anti-roll bar.

The rear has a low-pivot swing axle, radius arms, and coil springs. Being jointed only at the differential (lacking a modern constant velocity joint as used today with independent suspension), the swing axle could make rear end cornering treacherous at high speeds or on bad roads due to extreme changes in camber. This was remedied in the roadster by switching to a high-pivot geometry. A brake booster drew vacuum from the intake manifold to assist pedal effort. Brake shoes were wide. The front drums had double cylinders, the rear single. The handbrake was mechanical, acting only on the rear wheels. In March 1961 disc brakes replaced drums all round.

thumb|alt=A roadster with many other cars|The roadster was produced from 1957 to 1963

thumb|alt=A hard-top roadster parked on a street|300 SL hardtop roadster

Mechanically, the M198 engine power was boosted to , and the rear suspension enhanced by lowering the swing axle's pivot point below the differential centerline. The resulting notable improvements in handling and ride comfort it was available with custom configured leather luggage to maximize trunk space gained by moving the spare tire beneath its floor and shrinking the fuel tank.

Originally, the roadster came with a stowable soft top. In September 1958, an optional weatherproof hardtop became available. In 1951, the company built five V8 W165 cars and engines to enter the Grand Prix.

1952

The 300 SL's first race was the 1952 Mille Miglia. The race was from Brescia to Rome and back, pitting Karl Kling's 300 SL against Giovanni Bracco's new 3-liter V-12 Ferrari. Stirling Moss won the overall title at the 1955 Mille Miglia in a 300 SLR racing car, and John Fitch won his class in a production 300 SL coupé. The marathon Liege-Rome-Liege rally was won in 1955 by Olivier Gendebien, and in 1956 by Willy Mairesse. A 300 SL won the Sports Car Club of America Class D championship from 1955 to 1957.

1957–present

Horácio Macedo finished second in the 1960 Rali Vinho da Madeira. Former Gull Wing Group International president Bob Sirna set a Bonneville Speedway F/GT three-liter sports-car speed record of in a modified coupé in 2016.

Reception and sales

Sales quintupled in the model's second year but dropped off over the next three years.

Production numbers

{| class="wikitable" style="text-align:center; width:50em"

! || 1954 || 1955 || 1956 || 1957 || 1958 || 1959 || 1960 || 1961 || 1962 ||1963 || Total ||colspan="4"| Known to exist in 1994

!| Coupe

| 166 || 856 ||308 || 70 || || || ||

| | || || 1,400 ||colspan="4"| 1,200

!| Roadster

| | || || 618||267||200||241||256||182||94||1,858||colspan="4"|1,458

!| Total

|166|| 856 || 308 || 688||267||200||241||256||182||94||3,258||colspan="4"|2,658 available as coupe convertibles.

The gullwing-door V8 SLS AMG debuted in 2009 as the spiritual successor of the original 300 SL coupé. Produced through the end of 2014, it was replaced by the AMG GT, with traditional doors.

Mercedes-Benz 300 SL owners are supported by Gull Wing Group International, which began in 1961.

Replicas

thumb|300 SL from wood by Rémi Le Forestier

The Mercedes-Benz 300 SL was always popular with replica manufacturers. Mercedes-Benz, however, obtained a court order prohibiting faithful reproductions of the 300 SL, as the car's design is protected. For example, the Mercedes 300 SL Gullwing[40] and Mercedes 300 SL Roadster[41] models were produced in Germany by the Bavarian automobile manufacturer Scheib. Scheib initially built both models on its own chassis frames. The drivetrain and suspension, however, were taken from the Mercedes-Benz W 124. The Gullwing and Gullwing Roadster replicas came from Switzerland.

This legendary car has inspired many artists, some of whom have created life-size wooden replicas of artworks. A notable example is the famous wooden 300 SL with engine by French artist Rémi Le Forestier. He created it as a tribute to actor Alain Delon, who owned a car of this model in the 1950s.