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The Guide to Legal Car Modifications in Pennsylvania

The Guide to Legal Car Modifications in Pennsylvania ARENA Creative /

Whether you currently live in Pennsylvania or will be moving there, you need to know the regulations on vehicle modifications. The following information will help you make sure that your modified car or truck is considered street legal when you are driving on the roadways throughout the state.

Sounds and noise

Pennsylvania has regulations that affect the sound systems and the mufflers on your vehicle.

Sound systems

Pennsylvania requires that drivers do not play sound systems at levels that a reasonable person would consider unusual or excessive or that are audible at a distance of 50 feet. Prolonged playing of excessively loud music can be considered disorderly conduct.


  • Mufflers are required on all vehicles and must prevent unusual or excessive noise.

  • Headers and side exhausts are permitted if the remainder of the exhaust system limits the noise emitted by the engine and they do not increase the sound beyond the maximum decibel levels described below.

  • Muffler cutouts and bypasses are not permitted.

  • Motor vehicles traveling at 35 MPH or less must not exceed 88 decibels.

  • Motor vehicles traveling over 35 MPH must not exceed 92 decibels.

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

Frame and suspension

Pennsylvania frame and suspension lift laws are:

  • Vehicles cannot exceed 13 feet 6 inches in height.

  • Front lift blocks are not permitted.

  • Rear lift block cannot be more than five inches over the original factory height.

Max bumper height is based on the Gross Vehicle Weight Rating (GVWR) of the vehicle:

  • Cars and SUVs – Maximum front and rear bumper height is 22 inches.
  • GVWR less than 5,001 – Maximum front bumper height is 24 inches, rear is 26 inches.
  • GVWR 5,001-7,000 – Maximum front bumper height is 27 inches, rear is 29 inches.
  • GVWR 7,001- 9,000 – Maximum front bumper height is 28 inches, rear is 30 inches.
  • GVWR 9,001- 11,000 – Maximum front bumper height is 30 inches, rear is 30 inches.


Pennsylvania does not have regulations concerning engine swaps and modifications. However, emissions testing is required in several counties. Visit the Pennsylvania DMV Emissions Inspection website for more information.

Lighting and windows


  • Red and blue oscillating or flashing lights are for emergency vehicles only
  • Fog lamps are permitted with amber lights
  • Off road lamps must have opaque coverings when driving on roadways
  • Blue lights are for authorized vehicles only

Window tinting

  • Windshield tint is not permitted
  • Front side, back side and rear windows must allow over 70% of light to pass through
  • Front side and back side windows cannot have mirrored or metallic appearance
  • Side mirrors are required when rear window is tinted

Antique/classic car modifications

Pennsylvania offers a variety of plates for antique vehicles:

  • Antique plates are for vehicles that are over 25 years old and that have either been restored or maintained to the original manufacturer’s appearance and specifications.

  • Vintage plates are those issued between 1906 and 1976 and can be used on classic and antique vehicles of the corresponding manufacturer year.

  • Antique and vintage plates can only be used for vehicles that are not driven for general daily transportation. These vehicles are permitted to drive to and from educational, exhibition, club, and parade activities.

If you want to modify your vehicle yet still be within the laws in Pennsylvania, 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

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Related questions

Q: Power capabilities

Hi there. The engine will not start to break down or lose power at that point. The factory engine does not make that much power on its own so I have to assume you are talking about aftermarket power modifications....

Q: i cut off the roof

If you still have the windshield and install a roll bar then you should not have a problem, but if I were you I would check with local ordnance to make sure it is legal.

Q: Engine modification

Sounds like a nice build. Assuming you used the 305 crank, the engine will still be called a 5.0 or 305, since that is the cubic inch displacement of the engine.