Gasoline is made when crude oil is broken into various petroleum products by fractional distillation. A gasoline fuel tank stores gasoline on the car until the engine needs it. To fill a gas car, a nozzle from a fuel dispenser attaches to the fuel filler receptacle on the car. A fuel pump moves fuel from the tank to the engine's fuel injection system through the fuel line. The fuel injection system puts fuel into the engine's combustion chambers. These parts carry gasoline from the tank to the engine.

The engine block is the backbone of a gas engine: a large metal block. It has holes cut in it for the cylinders. The engine has pistons that move up and down. Most gas engines are four-stroke engines. They need four piston strokes to finish one cycle. In the intake stroke, the intake valve is open, and fuel and air are drawn into the cylinder. In the compression stroke, the piston squeezes the fuel-air mixture into a smaller space. In the power stroke, the burning gases push the piston.

A spark plug lights the fuel in a gas engine, and the fuel burns inside the engine itself. The crankshaft turns the up-and-down motion of the pistons into spinning motion. In a gas car, the transmission passes the engine's power on to the wheels. Gases go out through a tailpipe.

An electric car has an electric motor instead of a gas engine. An electric motor changes electrical energy into motion. Electric motors run quietly and smoothly. An electric car has far fewer moving parts than a gas engine.

An electric car stores its energy in a rechargeable battery. It uses the battery for fuel, in place of gasoline. All-electric vehicles have typical driving ranges from 150 to 400 miles, as of November 2026. The car has a charge port that connects the car to an outside power supply. The car is plugged in to charge. An electric car can be charged from a regular 120 volt outlet, which is the slowest type of charging, as of November 2026. Fully recharging an electric car's battery pack can take 3 to 12 hours, as of November 2026.

Words to know

• cylinder: engine chamber
• crankshaft: spinning engine part
• transmission: power passer
• battery: energy store