Mercedes’ secret racing SLS

The Gullwing coupé was always seen as the hardcore road-racing SL, but Mercedes was keen to stress the sporting credibility of its apparently easier-living sister, especially in its American market.

Mercedes built two race-ready Roadsters under the codename ‘SLS’ for Paul O’shea to contest the 1957 SCCA season. Although Alfred Neubauer had officially withdrawn Mercedes from competition following the 1955 Le Mans disaster, he still recognised the marketing value of racing. The O’shea cars were officially privateer entries but in truth they were secret factory specials engineered by Rudolf Uhlenhaut.

The public were led to believe they were watching a mildly-modified road car in action. In reality at least one of the cars had an aluminium body plus lightened racing seats, fake headlights without wiring, a plastic windscreen, alloy fuel tank and experimental aluminium-block engine. The racer supposedly weighed in at 1040kg but correspondence between Uhlenhaut and O’shea confirmed the weight of the aluminium-bodied car to be just 726kg. A standard 300SL Roadster was 1377kg.

O’shea’s Roadsters consistently finished among the front-runners but his season wasn’t the walkover his 1955 campaign had been with the Gullwing, and Neubauer ordered the special SL Roadsters to be sold ‘to enthusiasts of our marque who will not use them for racing’. The cars promptly disappeared, presumably back to the factory in Germany.