If the shape with the least air-resistance is a raindrop 💧, why are most cars shaped like a backwards raindrop? 🚗

Question

I am basing my question off this [image](https://study.com/cimages/multimages/16/dragcoefficients8851096396303799158.png)

Edit: Okay, okay, I should have said “teardrop” instead of “raindrop.” Talking about the *actual* shape of raindrops doesn’t really help given the visuals I provided.

In: 558

Answer 1

Not an expert in aerodynamics, so this is just a half answer. There are other considerations in automotive aerodynamics other than drag.

Downforce is more important for performance at the speeds the cars drive at, as this lets the car grip the road better at higher speeds. Cars with strong downforce often have a rear end that is broad, close to the ground, but then slightly tapering upwards at the very end.

Air intake both to cool radiators and feed the engine is also very important and likely also changes design considerations. This could prevent a very low drag shape. A smooth shape allowing for laminar (smooth and regular) air flow might cause air to pass around an intake rather than be funneled into the intake. With a teardrop shape, the very front is perpendicular to airflow as it deflects air *around* the cross section of the bulk of the object. If an intake were placed on such a shape that is flush with the shape, the laminar air flow would travel perpendicular to the intake duct. If the intake were instead elevated off the surface of the object, then the intake would contribute to a new “front cross section” of the shape and nullify the advantage of the front of the teardrop deflecting the incoming air.

Some expensive automobiles that are marketed based on top-speed capability do have a bit more of a teardrop shape, such as the McLaren Speedtail.