Flywheel

The flywheel is a heavy, circular metal disc attached to the back of the crankshaft. Its main job is to store rotational energy, helping the engine maintain smooth and consistent power delivery. When the pistons fire and spin the crankshaft, the flywheel keeps that energy moving forward during the moments between power strokes.

In manual transmission cars, the flywheel also connects to the clutch, allowing you to engage or disengage the engine from the transmission. It has gear teeth around its edge that mesh with the starter motor to get the car running. Over time, the flywheel can wear down, especially around the clutch contact surface, which may cause vibrations or slipping. Fun fact: performance cars often use lightweight flywheels to improve throttle response by reducing rotational mass.