Which component is primarily responsible for mixing and delivering fuel and air in older cars?

The carburetor is primarily responsible for mixing fuel and air in older cars. Historically, carburetors were a crucial component of the engine, essential for delivering the optimal fuel-to-air mixture required for combustion. They work by using the principle of differential air pressure to draw fuel from the fuel tank and mix it with incoming air, ensuring that the mixture is at the right ratio for efficient engine operation.

In contrast, other components listed, such as fuel injectors, are more relevant to modern fuel delivery systems, where fuel is sprayed directly into the combustion chamber rather than mixed beforehand. The throttle body manages the amount of air entering the engine but does not mix fuel and air itself; it operates primarily to control engine speed and power. The ignition coil is involved in igniting the air-fuel mixture rather than mixing it. Thus, the carburetor stands out as the correct answer in the context of older car models.