Mercedes-Benz dominated European sports car racing in 1952, finishing second on its debut in the Mille Miglia and then winning at Le Mans, the Nurburgring and in the South American Carrera Panamericana. The successful car was a lightweight coupe designed by Rudolf Uhlenhaut, known internally as W194. It took its engine and suspension from the existing 300 saloon and mounted them in a lightweight spaceframe chassis, clothed in a wind-cheating alloy body. Conventional doors were impossible because of the chassis design, so lift-up “gullwing’ doors were provided instead. The world soon knew it as the 300SL, the letters standing for ‘’sports lightweight’.
For 1953 Uhlenhaunt planned a series of improvements to the SL, including bigger wheels and tyres, a new form of swing-axle rear suspension and fuel injection for the 3.0-litre straight-six engine. But before the revised car could appear to competition Daimler-Benz management turned its focus away from sports cars to Formula 1 Grand Prix racing.
That might have been the end of the SL, had it not been for Austrian émigré Max Hoffman, importer of Mercedes-Benz cars to the US. Legend has it that Hoffman told Daimler-Benz management that if they built a road-going 300SL he could sell a thousand of them, and backed up his argument with a down-payment.
The production car used the new fuel-injected engine and a slightly longer version of the spaceframe chassis, but reverted to the conventional swing-axle rear suspension of the earlier racing SLs. It was also given a steel body with aluminium opening panels, resulting in a significant increase in weight. Racing SLs had been comfortably trimmed but the road car was even more luxurious, and was given a tilting steering wheel to aid entry and exit. The new car made its debut at the International Motor Sports Show in New York in January 1954.
Production began later that year and continued until 1957, by which time nearly 1400 examples of the ‘gullwing’ SL had been built. It was replaced by a 300SL Roadster, but the folding top and the conventional doors with their wind-down windows were just part of a package of changes which made the new version far easier to live with.
The spaceframe chassis was revised with lower sills to accommodate the normal doors, and extra bracing was introduced into the front bulkhead and above the transmission tunnel to restore the lost stiffness. Though the modifications were effective, they added about 220lb (100kg) to the weight of the car. Engine revisions produced an increase in power to compensate. Another significant change was the adoption of the low-pivot swing-axle design, which improved the Roadster’s on-the-limit handling.
Nearly 1900 Roadsters were built between 1957 and 1963, alongside more than 25,000 of the much cheaper – but visually similar – 190SL. Both were replaced by another Uhlenhaut masterpiece, the ‘Pagoda roof 230SL of 1963. By then the 300SL had established itself as a favourite of the rich and famous: filmstars Tony Curtis and Sophia Loren, King Hussein of Jordan, comedian Tony Hancock and jazz pianist Oscar Peterson all had them. The 300SL was the car to be seen in.
1954 Mercedes-Benz 300SL’Gullwing’
Engine 2996cc in-line six
Bore x stroke 85 x 88mm
Valvegear Single chain-driven overhead camshaft
Fuel system Direct fuel injection
Power 215bhp at 5800rpm
Suspension Front: double wishbones, coil springs, telescopic dampers, anti-roll bar; rear: swing axle, coil springs, telescopic dampers
Brakes Hydraulic drum brakes all round
Top speed 161mph (259km/h)
