Power bulge

A power bulge is a raised part (a bulge) of the hood of a car. The reason for a power bulge is to fit, for instance, a large engine or air filters that otherwise would not fit. Sometimes a power bulge is used to be able to fit a larger engine into a car that originally was not designed for it or it may be a design choice to be able to get a lower profile. As a power bulge is associated with performance cars, it may also be used as a design element to give the impression of a fast car.

The distinctive power bulge of an E-type Jaguar

Power bulge on the hood of a Saab Sonett V4.