50 Years of Great Sports Cars: Mercedes-Benz SL

Mercedes-Benz was already one of the greatest brands on earth by the time World War Two took the company into wartime production. Everybody who was anybody in Europe and in Hollywood drove a big Mercedes, from the crowned heads to the studio heads.

The war took a tremendous toll on the company and its factories, with close to 90 percent of all the factory buildings in Unterturkheim and Sindelfingen flattened. But in the late 1940s and early 1959s, the company would be rebuilt, re-engineered and re-energized for the prolonged period of postwar prosperity to come. The giant Mercedes sedans, cabriolets and sports cars were put aside in favor of more practical, more economical cars for postwar mass consumption. The Mercedes-Benz image car in 1951 was a 170 diesel sedan.

But the master plan for postwar prosperity at Mercedes-Benz included a quick return to racing, and by 1951 that plan was in place: a new sports car by the following spring and a new Grand Prix car by 1954. It would be a brand new and radical sports car design, with a tubular space frame, very high side sills for strength, top-hinged doors, and all the mechanical parts taken from the company's 300 luxury sedan series, introduced in April 1951. It would be called W194. With limited resources, the small sports car development team was more or less stuck with the 300 parts: a 3.0-liter inline sohc six-cylinder engine, the four-speed manual transmission, front and rear axles and suspension, all modified and tweaked for racing use.

The M186 passenger car engine was rated at a measly 115 bhp at 4600 rpm in the 300 sedan, but its architecture was both unusual and mechanically sound. It was also tall, so the first thing the designers did was tip the engine to the left 50 degrees and angle the cylinder head back 20 degrees to the block, with the crankshaft centerline offset several inches to the right of the car's centerline.

The cast-iron block was made with open water jackets on both sides, sealed off by stamped steel panels and gaskets. It used a seven main bearing crank with two-bolt main bearing caps and locating dowels, a forged steel crankshaft, forged rods and forged aluminum four-ring pistons. It was heavy, but it was as strong and as agile as the Me 109 had been. The cylinder head combustion surface was essentially flat, and the side combustion chamber was created by the shape of the piston crown, using a side-mounted spark plug in the block. The three Solex downdraft carburetors and the three-branch headers were both on the right side of the head.

The rest of the tube-framed car grew around the engine: parallel wishbone coil spring front suspension, and swing-axle rear suspension with coil springs, torsion bars for roll control and telescopic shock absorbers at all four corners. The rear track was a full 2.5-in. wider than the front track at 56.9 in., to keep the rear tires planted.

Brakes were huge 300x90mm Alfin, finned aluminum cooling housings mated to cast iron drums with Ferodo racing linings, the wheels 15-in. steel center/alloy rim knock-offs, and the tires 6.70x15 Continentals about as wide as your hand.

The 120-in. wheelbase of the sedan was reduced to a much sportier 94.5 in. for the 1,900-lb sports car, which by now had its real name-300 for the sedan from which it was derived, and SL for Sports Light: 300SL.

The ultralight round tube frame and aluminum skin made for a sports racing car that was light as a feather, strong as an ox and slick as a bullet, with a drag coefficient of 0.25!

The 300SLs made their racing debuts at the 1952 Mille Miglia, with Karl Kling, Hermann Lang and Rudy Caracciola, with Kling finishing second, Caracciola fourth and Lang retiring due to damaged rear suspension. Weeks later, 300SLs finished 1-2-3 in Bern, Switzerland with Kling, Lang and Fritz Reiss getting their first sweep. Caracciola, unfortunately, sustained a career-ending injury at Bern and moved to Indianapolis to recuperate with the family of Anton "Tony" Hulman, who owned and ran Indianapolis Motor Speedway.

The onslaught continued at Le Mans, where the 300SLs, now with the deeper gullwing doors required by Le Mans rules, scored a 1-2 finish with Lang and Reiss and Theo Helfrich and Helmut Niedermayr. The team cars were next raced as roadsters, aerodynamically dirtier than the coupes but more than 200 lb lighter, at the Nürburgring, and this time out Hermann Lang won and Kling was second.

The magic season was finished in November at the Carrera Panamericana, a 2,000-mile, five-day speed extravaganza where the factory team fielded both coupes and roadsters, with Kling/Klenk, Lang/Grupp and American John Fitch with navigator Eugen Geiger. After a great deal of trouble with their tires, they finished first, second and fourth (Fitch was later disqualified from fourth for making suspension repairs to the car). The makeshift coupe made from a passenger car became the most successful sports car of 1952.

Plans were made to produce a completely new design for the 1953 season that would address all the problems the original cars had displayed, from tire wear to power production to rear suspension, and prototypes were built but never raced, because Mercedes-Benz rennmeisters Alfred Neubauer and Rudy Uhlenhaut needed all the hands and money available for the 1954 Grand Prix program.

Other plans were being made in 1952 by the legendary Max Hoffman, the U.S. importer for Mercedes-Benz cars. He convinced the factory that American sports car nuts would buy roadgoing versions of the 300SL gullwing coupe. He showed Kling's Bern-winning car at car shows and sports car races during 1953, and gave the production 300SL and the smaller 220-based 190SL their world premieres in New York City in February, 1954.

Development of racing versions continued alongside the production cars, leading to the fabulous 300SLR roadsters of 1955 that won the Mille Miglia (with a GT class win by John Fitch in a production 300SL to boot), the Nrburgring, the Swedish Grand Prix and the Tourist Trophy in Ireland. They were leading Le Mans when they were withdrawn after the horrific accident of Pierre Levegh in a team car that exploded in the stands and killed 82 people. Mercedes-Benz won the sports car championship of the world in 1955, Juan Manuel Fangio and Stirling Moss became household names, and the factory quit racing in October of that year, a policy that stood for almost 35 years.

The factory built some 1,400 of the 300SL gullwing sports cars between 1954 and 1956 using aluminum hoods, decklids and doors, and a total of 29 all-aluminum 300SLs for racing by privateers. These cars were the first production cars ever to use the Bosch mechanical fuel-injection system, on their revised M198 six-cylinder engines.

Buyers could choose from three different suspensions, two camshafts (220 or 240 bhp SAE), four differential ratios, steel wheels, chromed wheels or Rudge knockoffs, two interiors, tartan cloth or leather, and the factory would paint a 300SL any color the owner wanted. The truck-like racing shifter was junked in favor of a shorter tunnel-mounted shifter, and the cockpit was made ready for road duty. Four out of five gullwings sold went to the United States.

Gullwings were raced very successfully by private teams all over the world in 1955-57, with drivers like Olivier Gendebien (Liege-Rome-Liege and Alpine Rally, 1955) Willy Mairesse (Liege-Rome-Liege, 1956), W.J. Tak (Tulip Rally, 1955), Werner Engel (European touring car championship, 1955), Armando Zampiero (Italian sports car driver's title, 1955), Paul O'Shea (SCCA D Production, 1955 and 1956), and Harry Carter (SCCA C Production, 1957). A steady stream of 300SLs went to Bonneville to set various speed records, capped by Los Angeles bandleader Don Ricardo's 153.711 mph run in 1961.

Production shifted to the 300SL roadster from 1957 though 1962 and required substantial re-engineering of the whole package. John Fitch's Mexican Road Race car was allegedly used as the mule for the production roadster. Renovations included a completely new low-pivot swing axle with a new "compensating" rear suspension design featuring lateral shock absorbers, wider front and rear tracks, a smaller fuel tank and, of course, conventional doors and a hideaway convertible top.

The roadster engine got the hotter sport cam grind as standard, and late in the model run, in 1961, all roadsters were fitted with Dunlop disc brakes, and the last few were fitted with aluminum engine blocks. The roadsters sold like nickel beer in the States, which consumed almost three quarters of the factory production from 1957 until the end in 1962, and some leftover cars were registered as late as 1964. There were only 1,858 of the sleek, snarling roadsters built in five years.

While the factory was officially out of racing in Europe, the SCCA welcomed the 300SL roadster into its D Sports class in 1957. They weren't allowed to run in production classes yet because of low production volume, so Mercedes-Benz's powerful racing impresario, Rudy Uhlenhaut, built two special ultralight cars for American racer Paul O'Shea.

These ultralights, with aluminum blocks, drilled suspensions, aluminum bodies, tanks and steering columns, magnesium bell housings and everything else superfluous, were the only two cars ever called 300SLS (it's the same old story; only two were built, but eight survive). O'Shea raced them nationally and won the class handily in 1957.

The second-generation Mercedes-Benz SL was the flat-topped, squared-off model that started life as the 230SL in 1963 and became known to fans as the Pagoda because of its roof shape. It came with a 170-bhp 2.3-liter six, the same 94-in. wheelbase as the original cars, and the same general suspension layout as the roadster, but it was in fact based on the 220SE sedan with all-new interior and exterior design, and the buyer's choice of hardtop or convertible. With a bigger 2.5-liter engine in 1967, it became the 250SL, and a year later, with a 2.8 inline six, the 280SL. They sold rather better than the originals, too, more than 50,000 units between 1963 and 1971.

Interesting sidenote: German amateur racers Eugen Bohringer and Klaus Kaiser won the Liege-Sofia-Liege rally in 1963, the 230SL's first time out as a race car.

Generation three was the 350SL/450SLC family introduced in 1971, with short- and long-wheelbase versions, the short ones with removable steel tops, and long ones with a much longer fixed top incorporating silver fins in the pillar. Buyer's choice was either a 3.5-liter V8 or a 4.5-liter V8 in the short car, the 4.5 only in the long car. Same spirit, 50 percent more displacement, two more cylinders.

These were vastly heavier and more comfortable cars than the previous versions, not suitable for racing, but they were rallied extensively in the late 1970s, winning the Tour of Britain in 1976, the 18,000-mile Argentine rally, and coming second in the East African Safari Rally with veteran Hannu Mikkola. Another fleet of 450SLC 5.0s finished 1-2-3-4 in the 3,500-mile Bandama rally in December, 1979. These were the first V8, automatic-transmission cars ever to win an FIA rally.

The 450SLC 5.0s were special lightweight 300-bhp 5.0-liter V8 versions of the 450SLC for Group 4, with aluminum engine blocks and reinforced chassis. In 1980, the factory modified them still more, calling it the 500SLC, and ran all season without a win until the last event of the year, the 3,200-mile Ivory Coast rally, which was won by Bjorn Waldegaard in a 450SLC with Jorge Recalde second in one of the new 500SLCs. Their point made, the factory pulled out of rallying a week before Christmas. That generation of SL, the last ever offered with a manual transmission, finished off as the 380SL, 500SL, and the rare 560SL, and lasted until 1989 with continuous upgrades like a four-speed automatic overdrive.

The fourth generation of the Mercedes-Benz SL was introduced in 1990 as a luxury two-seater and technology banner-carrier, and it was never raced above club level. Originally offered as 380SL or 500SL models, they fell victim to corporate name switching and finished their lives as SL380 and SL500, later joined by the SL600 V12, with the largest, most powerful (394 bhp) engine ever put in an SL. The angular beauty offered ABS, traction control, ESP yaw control, and a host of other technologies in a stylish two-seater that sold very well here, setting sales records in the last year of its life, 2001. Over the years, AMG built tons of upgraded SL500 and SL600 models for individuals and for the factory.

The latest generation SL500 was introduced here last fall as a 2002 model. Incorporating all of the base Mercedes technologies, plus the world's first electronically operated brakes and a folding steel convertible top, a whole new generation of 5.0-liter three-valve V8 engines, and an electronically controlled five-speed automatic, it is the quickest, fastest, most stable and comfortable SL of them all, starting at about $87,000. A really nice prize-winning 300SL gullwing is about $300,000. It may not have the quirky charisma of the original gullwing coupe, and it certainly doesn't weigh 1,900 lb, but the new SL500 is the technology leader of the entire Mercedes-Benz fleet, a car with amazing capabilities at ten tenths, especially in the SL55 AMG version. It'll go quicker, farther and faster and last longer than any 300SL Rudy Uhlenhaut ever dreamed of. We're just thankful that he dreamed of that first one.