4000S Superchargers are similar to turbochargers in that they compress the air that enters the engine. However, while turbochargers use exhaust line pressure to spool its condenser, the supercharger uses mechanical engine power to spool its condenser. Often American manufacturers elect to use 4000S Superchargers instead of turbochargers in order to reduce low end torque lag created by turbochargers while spooling.