(WFRV) – Ever wonder what that loud noise was coming from only for it to be a passing vehicle making enough sound to rattle windows. Is that legal in Wisconsin?

As the weather warms up and the snow melts, more ‘higher-end’ vehicles can be seen on Wisconsin roadways with some being louder than others. But what are Wisconsin’s laws about exhaust/mufflers?

Wisconsin state legislature says that no one should modify the exhaust system of any such motor vehicle in a ‘manner which will amplify or increase the noise emitted by the motor’. The legislature also mentions that the exhaust system shouldn’t be modified to increase the noise above what is emitted by the muffler originally installed on the vehicle.

The subsection also applies to motor bicycles, and vehicles must have an ‘adequate’ muffler that prevents any ‘excessive’ or unusual noise or ‘annoying’ smoke.

Additionally, ‘no muffler or exhaust system on any vehicle can be equipped with a cutout, bypass or similar device nor shall there be installed in the exhaust system of any such vehicle any device to ignite exhaust gases so as to produce flame within or without the exhaust system.’

However, for ATVs and UTVS, the Wisconsin Department of Natural Resources says those vehicles must have an exhaust system with a spark arrestor and cannot be louder than 96 decibels.

Each state has its own regulations/rules when it comes to mufflers/exhaust systems. In Maine, a muffler or an exhaust system can not emit noise in excess of 95 decibels. In multiple states, including the likes of Michigan and Pennsylvania, the decibel level limit varies depending on how fast the vehicle is driving.

An interactive map that shows each state’s exhaust noise laws, provided by SAN, can be viewed here.