The racing W194 300 SL was built around a welded aluminum tube spaceframe chassis to offset its relatively underpowered carbureted straight-6 engine. Designed by Daimler-Benz's chief developing engineer, Rudolf Uhlenhaut, the metal skeleton saved weight while still providing a high level of strength. Since it enveloped the passenger compartment traditional doors were impossible, giving birth to the model's distinctive gull-wing arrangement.