Saving energy and increasing autonomy by using the most appropriate way to reduce air resistance is the goal of every aerodynamics expert. “If vehicles were designed solely with this in mind, they would probably look like a teardrop,” he says. Marcel Straub, Head of Aerodynamics and Thermal Management at Porsche Engineering. “A tear moving across a surface is round at the front and very thin at the end. This shape allows air to flow with particularly low resistance, since there is no wake or drag against the direction of travel.”
Of course, the numbers verify this idea: a tear has a drag coefficient (Cx) of 0.05. This value, however, is virtually impossible to get in a real car. The reason has to do with the incompatibility between that form and the functionality of the design. Such a vehicle would present great challenges in terms of making the most of space, both in the passenger compartment and in the boot or even in the engine compartment.
On the other hand, the wheels also present complications, since they create turbulence and produce air flows around them that cause energy losses. In this case, a technology such as magnetic levitation could help solve the problem. More elements against? Unfortunately, the vehicle’s proximity to the ground doesn’t help either, because it prevents a perfectly symmetrical flow around the tear. When driving a few centimeters from the surface, it is practically impossible for there to be that symmetry in the passage of air.
To solve this, it would be necessary to drive or, rather, “fly” at a height of several meters. It is possible that before long we will see teardrop-shaped air taxis with sporty wings, soaring through the air and moving forward thanks to a propeller located at the pointed end of the aircraft. However, this design has been difficult to implement so far.
As a curious fact, it is worth mentioning that there is an existing form in nature that is even more aerodynamic than the tear: the penguin! This type of bird, when moving horizontally, acquires a Cx of 0.03, so if it were possible to make a car in the shape of the sea animal, it would be aerodynamically perfect as well as unmistakable.
But here too, the low-to-the-ground riding position, the wheels and the need to optimize space would thwart any attempt to turn this idea into reality. The history of the automobile presents some examples, almost all from the first half of the 20th century, of teardrop-shaped models. Such is the case of the ALFA 40/60 HP Aerodinamica from 1914 or the 1939 Schlörwagen which, despite the great efforts of its creators, did not go beyond the prototype phase.