A supercharger is a device driven from the engine which pressurises the air going into the engine, increasing the engine's power output. Superchargers are usually driven from the engine crankshaft by a belt or gear system.

The extra mass of air pumped into the cylinders by the supercharger allows more fuel to be burned, which means more power can be produced.

Compare turbocharger.

In-car entertainment: a speaker designed to reproduce only very low frequencies. Because low frequency sound is not perceived to be directional, a sub-woofer can be installed anywhere in the vehicle. They are often installed in the boot area.

See also: tweeter, woofer