A reader posed us an interesting question the other day about air intakes and grilles. Specifically: do electric vehicles need them at all and why do many internal combustion vehicles have such large examples. For conventional vehicles, an intake of some kind is necessary in order to dissipate the heat in the coolant that keeps the engine from melting.
While many modern cars, such as Audis, have what appear to be very prominent grilles these are actually mostly for stylistic reasons. If you actually take a close look at the grille area, you will find that much of it is actually closed off, particularly the upper areas. For optimum aerodynamics, air typically only flows through the lower grille. A prime example of this is the production version of the Chevy Volt. One of the changes from concept to production was closing off the main part of the grille.
Reader Torrey also noted that most electric vehicles like the Tesla Roadster and Dodge Circuit have grilles as well (see above). Even without an engine, these cars still have cooling requirements. The electronics, the motor and the battery all need to be cooled. The Roadster and Volt both use liquid cooled batteries with radiators in the front. Aerodynamicists always try to minimize the open area to cut drag but some openings are still needed. Thanks to Torrey for the tip!