Bonnet Scoops, Hood Scoops

A bonnet or 'hood' scoop is an air vent on the bonnet of an automobile that either allows a flow of air to directly enter the engine compartment, or appears to do so. It may be closed, and thus purely decorative, or serve to enhance performance in several possible ways.

One possible use of a bonnet scoop is to admit outside air into the engine's intake ahead of the air cleaner and carburetor or fuel injection manifold. In most modern automobiles, internal combustion engines "breathe" under-bonnet air or air ducted from under the front bumper through plastic and rubber tubing. The high operating temperatures in the engine compartment result in intake air that is 28°C (50°F) or more warmer than the ambient temperature, and consequently less dense. A bonnet scoop can provide the engine with cooler, denser outside air, increasing power.