Q An aeronautical engineer told me that for the shark fins on cars to aid in stability, the car would have to travel in excess of 250 km/h. Is this true? Does it even make sense to carry around the additional weight?
A While the engineer may be correct and impressively pedantic, he’s also curiously incorrect in judging the purpose of those little fins. The shark-like fins first popularised by BMW and now widely used are not for any kind of aerodynamic stability – they’re actually designed to house the various antennae bristling from today’s cars. Think about the signals moving through a car: AM/FM radio; satellite radio; cellular voice and data. All of those need independent receivers or emitters, but if they were separate, the car would look like a porcupine driving down the street. This way, the antennae are consolidated outside the steel roof, free from interference, but under a shark fin to reduce drag.