ROCKFORD, Ill. (WTVO) — Some drivers prefer dead silence while others want to let the whole world know they’re coming. Many car enthusiasts spend thousands of dollars on modifications to make their car sound or perform better, but are cars with loud exhausts legal in Illinois?

While it’s unlikely that you may often encounter 2019 Chevrolet Corvette ZR1 or a 2019 McLaren 720S Spider on Rockford streets (ranked by Car and Driver as two of the cars with the loudest factory exhaust, at 99 decibels a piece), you may have heard a Dodge Charger or a Ford Mustang with a loud engine exhaust (92 decibels) zipping around town.

According to Section 625 of the Illinois Vehicle Code, “No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all the requirements of this Section.”

However, Illinois also requires passenger and other vehicles under 8,000 pounds in weight to emit no more than 76 decibels on roads with a speed limit of 35 mph, and 85 decibels on a road with a speed limit over 35 miles per hour.

That means if you’re driving a Dodge Challenger Hellcat, with a massive V8 under the hood, letting out a factory-supplied growl of around 100 dB, it would be technically illegal to open it up at full throttle in Illinois.

According to Maximize Market Research, the global car modification market is a huge industry and is expected to reach $63.92 million by 2027, even though many of the products sold are technically not street-legal in many states in the U.S.

While analysts predict the future of the automotive industry will be built upon silent electric motors, there are several startups introducing aftermarket products that can add artificial engine and exhaust sounds to electric vehicles.

Dodge has introduced a Charger Daytona SRT EV concept that will produce a sound that replicates that of a revving engine, through a patented technology called a “Fratzonic exhaust system,” which is expected to produce 128 decibels of ear-shredding noise.

That’s about on par with the noise level of a rock concert, which can produce around 120 decibels of sound.

The Centers for Disease Control and Prevention says noise over 70 decibels for a prolonged period of time can damage a person’s hearing, and a loud noise over 120 decibels can cause immediate harm to the ears.