As early as 1947, an extremely streamlined car was developed with the V2 Sagitta. Better than BMW i3 or VW ID.3! Based on the VW Beetle.
The V2 Sagitta is a particularly streamlined VW Beetle from the post-war period – and at the same time unique.
If a car is particularly streamlined, then it uses less fuel or electricity, accelerates faster and reaches a higher speed. That is why the designers of modern (electric) cars try to build their vehicles with the lowest possible drag coefficient (cW) – but they have to make compromises with regard to the appearance of their vehicles. A typical problem here are the wheel arches/wheelhouses: if they were to be completely covered, the car would be more streamlined. But most customers want to see the wheels and especially the visually appealing (aluminium) rims. So the wheel arches remain open.
Even the Beetle was designed to be streamlined
However, the importance of the drag coefficient is not new knowledge; many decades ago, designers were already thinking about how they could make their cars as streamlined as possible. This was evident, among other things, in the shape of the VW Beetle developed in the 1930s, which was given a very successful streamlined body shape for the time.
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But the VW engineers could have built the Beetle even more streamlined. This is proven by the prototype V2 Sagitta from 1947, which has now been tested for its aerodynamics in a modern wind tunnel (the word Sagitta comes from Latin and means “arrow”).
The measurement drive with a Volkswagen vintage car in the Wolfsburg climatic wind tunnel resulted in a surprisingly low drag coefficient.
Some drag coefficients
VW Beetle from the 1940s has a cd value of 0.46 with a frontal area of 1.80 square meters (the cd value of the VW beetle has changed again and again over the decades due to slight changes to the body shape and the windshield ).
the VW designers had significantly optimized at the time with a view to streamlining. The result was an impressive drag coefficient of 0.217 and a frontal area of 2.10 square meters.
For comparison: the Golf VII, the predecessor of the current Golf generation, had a drag coefficient of 0.27 with a frontal area of 2.19 square meters. The so-called 1-litre car Volkswagen XL1 still undercut these values - cd value 0.189, frontal area 1.50 square meters – but unlike the Golf it was not a mass-produced model, but was only produced in a very small number.
The BMW i3, on the other hand, has a drag coefficient of just 0.29 and the VW ID.3 0.267! So the V2 Sagitta from 1947 is still great.
Streamlined details go back to basic research by Baron von König-Fachsenfeld.
Sagitta was created in the 1940s
The V2 Sagitta was named after its builder, Kurt Volkhart. Volkhart had already started in the early 1940s to develop aerodynamic sports versions of the Beetle based on fundamental research by the aerodynamicist Baron von König-Fachsenfeld – including uncompromising streamliners with a continuous dorsal fin. But only his Sagitta project was finally completed – in 1947 – with a lightweight aluminum body (the original Beetle body is heavier steel) on a tubular steel trellis frame (matching the original Beetle).
The engine of the V2 Sagitta from 1947 remained unchanged compared to the standard engine: the air-cooled boxer engine had a displacement of 1.1 liters and delivered 24.5 hp. Thanks to the streamlined design, which is similar in detail to the body of the Porsche 356 (the predecessor of the 911), an impressive 140 km/h was possible with the small engine.
The V2 Sagitta only underwent a modern technical test in the wind tunnel in January 2013, after the car that had been thought to be lost had come into the public eye again during a Concours d’Elegance: The team around Dr. At that time, Alexander Wittmaier from Volkswagen Research and Development had the vehicle transported from its location in Austria to Wolfsburg in order to evaluate its aerodynamics in the wind tunnel.
If you remove the wheelhouse cladding, the cW value deteriorates.
Small details make a big difference
In the course of testing the V2 Sagitta, the aerodynamic effectiveness of individual measures such as the wheelhouse cladding was also examined. If you remove them, the drag coefficient drops to 0.252. If, on the other hand, the windshield wipers are removed or a small rear spoiler is used, the drag coefficient is reduced to 0.216.