In 1945, Daimler-Benz, like the rest of German industry, lay in ruins. After two weeks of attention by the Eighth Air Force and the RAF, the firm's main plants at Stuttgart-Unterturkheim and Sindelfingnen were totally demolished. Daimler's board of directors flatly stated that the firm had ceased to exist. After they cleared the rubble, Daimler-Benz was back in business on a small scale, repairing American army vehicles. Soon the company was buying pre-war Mercedes models, restoring them, and bartering the cars for raw materials. By early 1946, Daimler, just like the American car industry, was cranking out new copies of its pre-war models.
In 1951, Daimler-Benz decided it would tell the world that it had arisen from the ashes in the most dramatic way possible - by returning to the race track. Several of the old pre-war W163 racers were bought out of private hands (two cars were found on a Berlin used-car lot) and once again set out to do combat. They were sent to the 1951 Argentine Grand Prix and failed miserably. At a New Year's celebration in late 1951, Daimler-Benz general manager Willhelm Haspel announced that it would return to racing with a completely new design, the 300 SL. The engine was a much-developed version of the 3-liter motor used in the 300, a large, heavy luxury limousine. SL stood for "Super Leicht", and the new, purpose-built race car was shown to the press on March 12, 1952.
Mercedes entered the 300 SL in its first event, the 19th running of the Mille Miglia, the following May. Karl Kling finished second to a Ferrari with pre-war Mercedes great Rudi Caracciola fourth in another 300 SL. Another name from pre-war Silver Arrow history, Hermann Lang, struck a mile marker and retired. Just a month later, on June 13, 1952, Mercedes entered three cars at Le Mans, ending a 22-year absence. The Mercerdes team, directed by the imposing figure of Alfred Neubauer, drove a calculated race, holding back, letting faster competitors run ahead and break.
When it was over Hermann Lang/Fritz Riess had won outright, followed by Theo Helferich/Norbert Niedermayer. Mercedes had demonstrated in the most convincing terms its resurrection from the ashes of war. Daimler-Benz was, in effect a microcosm of the "German economic miracle" then just getting under way. Other victory laurels would grace hoods of factory 300 SLs, most notably the 1952 Carrera Panamericana. The car, like so many other sports cars from the 1950s, owed its existence to the American importer of Mercedes, V Hoffman. It was Hoffman who suggested that Mercedes build a street version of the racing six-cylinder coupe. Opinions at Daimler-Benz were divided, but Hoffman was prepared to put his money on the table, placing an order for 1000 cars. This would also prompt the design of the 300 SL's smaller cousin, the 190 SL, with a similar thousand-car order.
Appropriately, the street-going version was first shown to the public not in Europe but at the New York Auto Show, in February 1954. Production got underway in early autumn. The 300 SL for public consumption consisted of a steel body over a multi-tube frame. Doors, hood and trunk were of aluminum. For competition use, customers could order an all-aluminum body, and 29 such lightweights were built. For rigidity, the tube frame formed large, wide box sections on either side of the cockpit. The only way to get an adequate door opening was to make the doors swing upward on spring-loaded struts from the roof centreline. The result has been known ever since as the Mercedes Gullwing.
The front suspension, consisting of unequal-length A-arms, coil springs over the tube shocks, and an anti-roll bar, was taken from the 300 sedan. The rear suspension, with coils over tube shocks and individually pivoted swing axles, came from the same source. The first 150 Gullwings had ZF worm-and-nut steering but this was changed to Mercedes recirculating ball for later cars. Customers with racing intentions could order optional Rudge knock-off hubs (heavier, but they made for quicker tire changes), competition shocks and stiffer springs. Standard tires were 6.50 x 15 bias-ply on 5-inch wide rims. For racing, customers could choose 6.70 x 15 on 5.5 x 15 wheels.
The Gullwing used huge A1-fin drum brakes with "turbo fins" to promote cooling. The A1-fin process consisted of a silicon-aluminium drum shrunk onto a steel hoop; the aluminium shell could conduct the heat away faster than a normal cast-iron drum. At the time, the 300SL's brakes were considered the last word in stopping power. While the competition 300 SL had used carburettors, Mercedes and Bosch called on their wartime experience with the DB 600 series of aircraft engines, and their mechanical fuel injection system - Mercedes was not the first to use Bosch mechanical fuel injection on a road car, but the German post-war minicars which first bought the Bosch system have long been forgotten.
Customers could choose from two states of tune, the standard 164kW or 179kW with the racing cam. The SL engine used a conventional overhead cam, actuating the valves through finger followers as the famed desmodromic valves of the racing Mercedes were too complex for civilian use. To cope with the engine's heat output, the 300 SL used 16 liters of oil in a dry sump system, with an oil cooler up front next to the radiator. Functional air outlets behind the front wheel openings provided additional cooling. The factory claimed a fuel consumption of 19 litres/100 km under hard driving, 9.5 litres/100 km at a steady 80 km/h. Combined with a huge 130-liter fuel tank the car had a realistic cruising range of well over 500 miles at high speed.
The 300 SL had a four-speed fully synchronized gearbox, and customers could choose from a series of final drive ratios. Unless otherwise specified, the U.S. market coupe came with 3.64 gears. The optional ratios were 3.42:1 and 3.25:1, for increased top speeds. The factory claimed a top speed of 155 mph for the tallest final drive ratio. Inside, the steering wheel could be released to flop down for easier entry. The driver and passenger sat in bucket seats covered in gabardine in a choice of blue, red, or green plaid, combined with MB-Tex (vinyl). The side windows were not lowerable but could be removed entirely and stowed in pouches. The vent windows could be opened for more fresh air if the car's ventilation blowers were inadequate.
Strangely the 300 SL coupe did not sell was well as Daimler-Benz would have liked; only 76 coupes were sold in 1957. Total coupe production reached 1400 units. Mercedes replaced the coupe with the heavier 300 SL roadster in 1957; before production ceased in favor of the pagoda-roof 230 SL in 1963, Mercedes built 1858 roadsters. The 300 SL coupe was the dream car of its day, the ultimate exotic. As exciting as the Gullwing had been, though, the 300 SL roadster was an even better engineered car. The frame was completely redesigned, to lower the engine and transmission and provide stiffness despite the lack of a roof and the conventional front-hinged doors cutting into the sill boxes. The swing axles were now pivoted from a single lower central joint below the differential, for a lower roll centre and somewhat less quirky cornering. A compensating spring linked the two swing axles, allowing the main springs to be softer. The steering was slowed down, to three turns lock-to-lock. Fuel capacity was reduced to 100 litres.
In contrast to the Gullwing, the roadster's trunk provided usable luggage space. Like the coupes, early roadsters had the 8.55 compression ratio, later replaced by 9.5:1. The formerly optional competition cam became standard equipment. Later roadsters switched to Michelin X radial tires. Disc brakes replaced the A1-fin drums in 1961. Leather buckets later took the place of the earlier cloth seats. A detachable steel hard top was optional. The lucky few that have driven the 300 SL have claimed that it is surprisingly docile when driven normally. Although it had long throws, the shifter was quick, crisp and precise. There was a bit of gear whine, but this was normal. In acceleration tests, the gullwing coupe went to 100 km/h in 9.04 seconds, through 400 metres in 16.56 at 138.4 km/h. The roadster was next quickest, at 9.04, 16.42 and 137.9 km/h. The high-compression hardtop roadster did 0-100 in 9.05 seconds, the 400 m in 16.37 at 140.0 km/h. Perhaps the biggest criticism of the 300SL lay with the swing axle. Not that these were necessarily all that bad, but they could be tricky and required a little bit of getting used to.
