Does a Muffler Make Your Car Louder?

Car power enthusiasts have always loved loud engines. It made the muscle cars of the '60s and '70s sound more beastly. They make the customized speed demons of the 21st century sound more powerful. Does the muffler make these cars so loud?

Purpose

  • Mufflers are designed to reduce noise, not enhance it. The noise from the internal-combustion engine is caused when gases go from the high pressure trapped in the cylinder to the open atmosphere outside the car, causing a very loud mechanical rumble when there is no muffler present. Mufflers reflect this noise back toward the engine through a pipe before it’s released to the air.

Law

  • Most states require all cars to have a muffler to reduce noise. Loud engines can violate noise ordinances as well as motor vehicle laws. In some states, muffler noise may even be regulated to the decibel.

Customization

  • Hot rodders will use aftermarket mufflers to give their cars that authentic race car sound. However, they must be careful, because some state laws have regulations for mufflers and loudness. This can also happen when hot rodders rebuild their exhaust systems to give themselves more power. Aftermarket exhaust systems for speed often come with louder mufflers, which may require a pre-silencer for regular street driving.