A sedan works through coordinated systems that turn stored energy into motion, support the body and occupants, steer the tires, and control speed. Its familiar passenger cabin and rear luggage space describe the body layout, while the powertrain and chassis determine much of the mechanical behavior.
Sedans can use combustion, hybrid, plug-in hybrid, or battery-electric propulsion, and they can drive different combinations of wheels. Their suspension and braking equipment also vary. Understanding the main systems helps explain ordinary driving without assuming that every four-door car contains the same hardware.