What vehicle component relies significantly on proper fuel supply?

The engine is the vehicle component that relies significantly on proper fuel supply because it is the part responsible for converting fuel into energy to power the vehicle. The combustion process within the engine relies on a precise mixture of air and fuel. If the fuel supply is insufficient, it can lead to poor engine performance, reduced power output, and increased emissions. Proper fuel delivery is essential for the engine to run smoothly and efficiently, affecting overall vehicle performance, responsiveness, and fuel economy.

Other components, such as the transmission, exhaust system, and braking system, operate independently of the fuel supply. While they are critical to the vehicle's operation, their functionality is not directly tied to the amount or quality of fuel available. For instance, the transmission transmits power from the engine to the wheels, and the exhaust system manages emissions; both systems have distinct functions that do not involve fuel supply in the same direct way as the engine.