What Is the Function of a Muffler?

by Daniel Brecht
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Mufflers are installed on cars and motorcycles to increase airflow out the engine by dissipating exhaust gases. They are also used to suppress exhaust noises by decreasing sound levels emitted by the engine.


Mufflers are the last part of the exhaust system. By channeling exhaust gases, they promote better airflow in the engine, which allows for better combustion and, in turn, translates to better performance and gas mileage.

Sound Suppression

A muffler channels the pressure waves created by the engine valves and bounces them around a chamber, creating opposite waves. The clash of the two sets of waves annuls each one, and the emitted noise is muffled.


Mufflers come in varying lengths, designs and material. Performance mufflers are designed to provide more power output rather than noise reduction. A straight muffler increases maximum airflow of exhaust by allowing gases to pass through the muffler and out the tailpipe quickly. A muffler that is curved restricts exhaust airflow, but it can produce a sportier "roaring" sound.

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