Muffler

A muffler, also called a silencer, is a device in an internal combustion engine's exhaust system that reduces the noise produced by exhaust gases as they exit the vehicle. It is typically located along the exhaust line between the engine and the tailpipe, and may be integrated with other exhaust components such as the catalytic converter and resonator.

Most mufflers consist of an outer shell and an interior assembly of tubes, chambers, and baffles. The arrangement may include perforated tubes and packing material to absorb sound. There are two common design approaches: chambered mufflers, which use a series of tuned cavities to reflect and cancel sound waves, and straight-through or perforated-tube mufflers, which provide higher flow with less damping. Some systems include a separate resonator to further tailor noise.

Mufflers are used on cars, motorcycles, trucks, lawn and garden equipment, and various power tools. In many regions, noise emission standards regulate muffler performance, and proper maintenance is required to meet these limits. While mufflers primarily target noise, modern exhaust systems may place them downstream of a catalytic converter to balance acoustic goals with emissions reduction.

Maintenance and wear can affect muffler performance. Corrosion from heat and moisture, physical damage, or leaks can cause loud operation, rattling, or reduced efficiency. Replacement may involve vehicle-specific units or universal models, and proper installation is important to maintain both noise control and exhaust flow.