Skip the auto shop - Our mechanics make house calls

The Guide to Legal Car Modifications in Kentucky

The Guide to Legal Car Modifications in Kentucky ARENA Creative /

Whether you live in Kentucky or are moving to the area, you need to know what vehicle modifications are permitted so that your car or truck is street legal. The information below will help you make sure your vehicle is in compliance with the Kentucky laws.

Sounds and noise

Kentucky has sound regulations that affect the sound system and muffler on your vehicles.

Sound system

  • Sound can’t emit from your vehicle or property that unreasonably interferes with others and their enjoyment or ability to do business. There are not set limits as to how loud this may be.


  • Mufflers are required when driving a vehicle on the highway.

  • Mufflers with cutouts are not permitted on the highway.

  • Vehicles used on and off highway can’t have modified exhaust systems that amplify the sound beyond that of the original manufacturer.

Tip: Also check with local county laws in Kentucky to make sure you are following any municipal noise ordinances that may be more stringent than state-level laws.

Frame and suspension

Kentucky does not place any limits on suspension lifts, frame lifts or bumper heights, but vehicles can’t be taller than 11 feet 6 inches.


Kentucky does not require emissions testing and currently has no laws concerning engine modifications or swaps.

Lighting and windows


  • No flashing lights are permitted on passenger vehicles other than amber hazard lights.

  • No colored (red, green, yellow or similar) flashing lights can be used within 100 feet of highways maintained by the state.

Window tinting

  • Non-reflective tint can be applied to the top of the windshield above the AS-1 line from the manufacturer.

  • Front side windows must allow over 35% of light through.

  • Back side and rear windows must allow over 18% of light through.

  • Front side and back side window tint can’t be over 25% reflective.

  • Legal tinting identification sticker must be affixed to the doorjamb on the driver’s door.

Antique/classic car modifications

Kentucky also has regulations for classic or antique vehicles.

  • Antique vehicles that are 25 or more years old qualify for a historic plate.

  • Historic vehicles are not used for daily transportation, but are used for tours, parades, and exhibitions.

If you want to make vehicle modifications but you want to ensure they follow Kentucky law, 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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

How to Find the Keyless Code on a Ford Explorer or Mercury Mountaineer
Many Ford Explorers and Mercury Mountaineers were manufactured with an option known as the Ford keyless entry keypad. Some models refer to it as SecuriCode as well. It...
P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem What the P0121 code means P0121 is a generic OBD-II code which indicates that the Engine Control...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...

Related questions

Q: I want to know what engines would fit my motor mounts properly

Hello. The biggest engine that this vehicle originally came equipped with was the 5.7L V-8. This is the 350 cubic inch version. I am not sure what modifications to your vehicle that would need to be done to make this...

Q: Can I put an XLR v engine in my 2001 caddilac deville. I want more power out of my big caddy.

The XLR-V motor is in fact a Northstar type engine, so yes it should work, but it will be very expensive. The engine alone will cost quite a bit, and you're gonna need to run the wiring harness for the...

Q: I have a MB WDB2011281F343389-0 and I know it: It would be advantageous to place an intercooler and how to get a design for this?

Admittedly, the 190D is not a big performer, so it's understandable that you would want to do something to improve the power, but I don't think there is much out there for that car. If you are determined, however, there...