What is the primary function of an exhaust system?

The primary function of an exhaust system is to channel exhaust gases away from the engine and reduce noise. This system plays a crucial role in the overall performance and efficiency of a vehicle. By directing harmful gases produced during combustion away from the engine and exiting through the tailpipe, the exhaust system helps prevent the accumulation of toxic emissions within the vehicle, ensuring that the air inside the cabin remains safe for passengers.

In addition to directing exhaust gases, the exhaust system is designed to minimize noise generated by the engine. This is achieved through various components like the muffler, which dampens the sound of the exhaust gases as they exit the vehicle.

While the other options mention elements that may contribute to vehicle performance, they do not represent the primary purpose of an exhaust system. Improving fuel efficiency and power is more related to the engine's design and tuning. The cooling of the engine is typically managed by the cooling system, which incorporates a radiator and coolant, while filtering impurities from exhaust gases relates more to components like catalytic converters that have a specific function in emissions control, rather than the overarching role of the exhaust system.