A supercharger forces more air into an engine than it would otherwise breathe. More air means more fuel can burn, and more fuel means more power. The supercharger is driven mechanically, usually by a belt from the crankshaft. That direct drive gives instant response. It also costs some engine power to turn.

Superchargers date back to the early 1900s and saw heavy use on aircraft engines and land-speed racers. Detroit put them on production cars in the 1930s. Today they compete with turbochargers, which use exhaust energy instead of a belt.

Supercharger types

• Roots: two meshing rotors, common on American V8s.
• Twin-screw: more efficient, popular in aftermarket kits.
• Centrifugal: looks like a turbo but driven by a belt.
• Eaton-style: OEM favorite for low-end torque.

The main advantage over a turbo is response. There is no lag because the supercharger is always spinning with the engine. The main disadvantage is efficiency. A turbo reclaims waste exhaust energy. A supercharger takes power from the crank to make power. For towing, off-roading, and muscle cars, that trade-off often makes sense.