An automobile's electrical system runs on DC power and the bulk of that power is supplied by the battery. The alternator converts the motion of the rotor into AC power which is then fed through the rectifier to convert it to DC power that both the car and the battery can use.

The lighting system consists of interior lights, instrument panel lighting, headlights, and taillights. Like household electrical circuits, the vehicle's lighting system is protected from current spikes by fuses and circuit breakers.

Fuel injection has replaced the carburetor as the primary automobile fuel delivery system. The main difference between the fuel injector and the carburetor is that fuel injection atomizes the fuel by forcibly pumping it through a small nozzle under high pressure while a carburetor relies on suction to draw fuel into an accelerated intake air stream.

An overcooled engine is less efficient. During the power stroke, combustion heat pushes down the piston. If too much of this heat is lost to the cooling system, the fuel might not combust completely and contaminate the engine's lubricating oil diminishing its lubricating ability. Incomplete combustion of fuel also negatively affects the engine's fuel efficiency and power output.

The water pump is driven by a belt connected to the crankshaft and ensures that coolant moves through the engine and radiator.