What component is responsible for converting fuel into power in a car?

The engine is the component responsible for converting fuel into power in a car. It achieves this through a process called combustion, where air and fuel mix and ignite within the engine's cylinders. This ignition pushes the pistons down, creating mechanical power that ultimately drives the vehicle. The engine is essentially the heart of the vehicle, transforming the chemical energy stored in fuel into kinetic energy, which propels the car forward.

In this context, the other choices serve different functions within the vehicle's system. The transmission helps to control the power generated by the engine and manage the vehicle's speed and torque but does not convert fuel into power. The starter motor is essential for initially starting the engine but does not play a role in the continuous conversion of fuel during operation. The fuel injector, while crucial for delivering the right amount of fuel into the combustion chamber, is merely a part of the engine's fueling system and does not perform the conversion itself. Thus, the engine is the core component when it comes to converting fuel energy into power.