Karl Schlör and the Schlörwagen. Often called “the egg” or “the pillbug car.” Photos from www.dieselpunks.org.

The Schlörwagen, developed by Karl Schlör and presented to the world at the 1939 Berlin Auto Show, where it became the star of the show. Schlör, worked as an engineer for Krass Maffei of Munich, a firm that built locomotives and steam engine vehicles. Intrigued by aerodynamics, he proposed a body shell for a passenger vehicles with an extremely low drag coefficient as early as 1936.

Designed to seat 7 passengers, this German streamline prototype was the star of the 1939 Berlin auto show.

A model was constructed and tested at the AVA Aerodynamic Testing Institute in Gottingen that showed a drag coefficient of 0.113 – an unthinkable number then and still very impressive by today’s standards. Working with the Ludewig Brothers of Essen, an aluminum body was built and mounted on a Mercedes-Benz 170H rear engine model chassis. Tests on this motorized version showed a drag coefficient of 0.186, which was only slightly higher but astounding for the time. For reference, today’s vehicle’s drag coefficient range between 0.25 to 0.30.

The production car on which the Schlörwagen was based, a Mercedes-Benz 170 H, achieved a maximum speed of around 65 mph, while the aerodynamic version recorded a remarkable 84 mph. The fuel mileage for the experimental car was equally impressive. The original production Mercedes used 10 to 12 liters of fuel to drive 100 kilometers where the Schlörwagen consumed eight litres of fuel. This was a reduction of 20 to 35 percent in fuel mileage. Keep in mind, this car was designed to fit 7 people.

With the start of World War II, the project was shelved and the car was never mass produced. At the end of the war, the car was reportedly taken to Russia and further testing was done. No one knows where the sole functioning model went, or what became of the model. The designer, Dr. Karl Schlör passed away in 1997, taking his designing secrets with him.