If you live in Michigan or are planning on moving to the area, you need to know about the vehicle modification laws in the state. Following these modification regulations will help ensure that your vehicle is street legal when driving throughout the state.
Sounds and noise
Michigan has regulations concerning the sound system and the muffler on your vehicle.
- 90 decibels when traveling 35 MPH or more, 86 decibels at 35 MPH or less.
- 88 decibels when stationary.
Mufflers are required on all vehicles and must work properly with no holes or leaks.
Muffler cutouts, amplifiers, bypasses or other modifications that are designed to amplify the sound are not permitted.
Tip: Also check with local county laws in Michigan to make sure you are following any municipal noise ordinances that may be more stringent than state-level laws.
Frame and suspension
Michigan has the following regulations on frame and suspension height:
Vehicles cannot be taller than 13 feet 6 inches.
Vehicles cannot have tie rods, drag links or pitman arms welded to the vehicle to affect steering.
Front lift blocks are not permitted.
One-piece rear lift blocks with a height of four inches or less are permitted.
Spring shackles longer than two inches beyond stock length are not permitted.
Vehicles with GVWR less than 7,500 have a maximum frame height of 24 inches.
Vehicles with a GVWR of 7,501-10,000 have a maximum frame height of 26 inches.
Vehicles with a GVWR of less than 4,501 have a maximum bumper height of 26 inches.
Vehicles with a GVWR of 4,-7,500 have a maximum bumper height of 28 inches.
Vehicles with a GVWR of 7,501-10,000 have a maximum bumper height of 30 inches.
Michigan does not have engine modification or swap regulations and does not require emissions testing.
Lighting and windows
No more than 4 lights of 300 candlepower can be lighted at one time of the highway.
Markers lamps, reflectors and clearance lamps on the front of the vehicle must be amber.
All rear lighting and reflectors must be red in color.
License plate light must be white.
Two side fender or cowls lamps in white or amber light are permitted.
One running board light per side in amber or white are permitted.
Flashing or oscillating lights (other than amber hazard lights) are not permitted on passenger vehicles.
Non-reflective tint can be applied to the top four inches of the windshield.
Front side, back side and rear windows can have any tint darkness.
Side mirrors are required if back window is tinted.
Front side and back side window reflective tint cannot reflect more than 35%.
Antique/classic car modifications
Michigan requires those with historic vehicles to fill out an Application and Certification for Michigan Historic Plates. Additionally, these vehicles are not allowed to be used for normal, daily transportation.
If you want to make sure your modifications are within Michigan laws, YourMechanic can provide the mobile mechanics to help you install the new parts. You can also ask our mechanics what modifications may be best suited to your car using our free online Q&A system, Ask a Mechanic.