How Do Gasoline Cars Work?

Gasoline and diesel vehicles are similar. They both use internal combustion engines. A gasoline car typically uses a spark-ignited internal combustion engine, rather than the compression-ignited systems used in diesel vehicles. In a spark-ignited system, the fuel is injected into the combustion chamber and combined with air. The air/fuel mixture is ignited by a spark from the spark plug. Although gasoline is the most common transportation fuel, there are alternative fuel options that use similar components and engine systems. Learn about alternative fuel options.

Key Components of a Gasoline Car

Battery: The battery provides electricity to start the engine and power vehicle electronics/accessories.
Electronic control module (ECM): The ECM controls the engine's performance, fuel efficiency, and emissions; safeguards the engine from abuse; monitors the operation of the vehicle; and troubleshoots mechanical problems.
Exhaust system: Channels the exhaust gases from the engine out through the tailpipe.
Fuel filler: A filler or "nozzle" used to add fuel to the tank.
Fuel injection system: This system inserts fuel into the engine's combustion chambers for ignition.
Fuel line: A metal tube or flexible hose (or a combination of these) allows for transferring fuel from the tank to the engine's fuel injection system.
Fuel pump: A fuel pump transfers fuel from the tank to the engine's fuel injection system via the fuel line.
Fuel tank (gasoline): Stores gasoline on board the vehicle until it's needed by the engine.
Internal combustion engine (spark-ignited): In this configuration, fuel is injected into the intake manifold or combustion chamber and combined with air, and the air/fuel mix is ignited by the spark from a spark plug.
Transmission: The transmission transfers mechanical power from the engine and/or electric traction motor to drive the wheels.


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