Skip the auto shop - Our mechanics make house calls

The Guide to Legal Car Modifications in New Hampshire

The Guide to Legal Car Modifications in New Hampshire ARENA Creative / Shutterstock.com

Whether you live in New Hampshire or plan to move there in the near future, you need to understand the laws surrounding vehicle modification. Understanding the following regulations will ensure that your vehicle is street legal when driving on the roadways throughout the state.

Sounds and noise

New Hampshire has regulations in place that cover the muffler on your vehicle. Failure to follow them can result in a $100 fine for the first offense, $250 for the second offense, and $500 for each additional offense.

Mufflers

  • Mufflers are required on all vehicles and must be in working condition to limit unusually loud or excessive noise.

  • Muffler bypasses, cutouts, and similar devices are not permitted on roadways.

  • Straight pipes are not permitted.

  • After-market exhaust systems are permitted providing they are not excessively loud (exact loudness levels are not defined).

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

Frame and suspension

New Hampshire does not have frame or suspension lift height restrictions. However, other regulations include:

  • Vehicles cannot be more than 13 feet 6 inches in height.

  • Minimum bumper height for cars, SUVs, and trucks is 16 inches.

  • Cars and SUVs bumper height cannot exceed 20 inches.

  • Truck have a maximum bumper height of 30 inches.

  • Lowered suspension systems cannot allow any part of the chassis, steering or suspension on the vehicle to be lower than the lowest portion of the wheels.

Engine

New Hampshire does not have engine modification or swap regulations. However, annual safety inspections are required. Emissions testing is also required for vehicles manufactured after 1996.

Lighting and windows

Lights

  • Two spotlights are permitted providing that the high-intensity part of the beam does not strike windows, mirrors or the windshield of another vehicle on the roadway.

  • Three auxiliary lamps are permitted.

Window tinting

  • Non-reflective tint is permitted on the top six inches of the windshield.
  • No tint is permitted on the front side windows.
  • Back side and rear windows must allow over 35% of light through.
  • Side mirrors are required if back window is tinted.
  • Reflective tint is not permitted.

Antique/classic car modifications

New Hampshire provides Antique plates for vehicles that are more than 25 years old. However, these vehicles can only be used for public interest activities such as parades, club activities, and exhibitions.

If you want your vehicle modifications to comply with New Hampshire 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
Icon-warranty_badge-02

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

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.

GET A QUOTE

More related articles

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...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...


Related questions

Q: Went with bigger tires & installed a high flow filter/muffler

Anytime you make changes to the tire's overall diameter, multiple components are going to be thrown out of calibration including, ABS, speedometer and traction control. There was a time when a professional mechanic could reset ECU's, but recent changes in...

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: Question about acceleration improvement.

There are zero options to "improve" the acceleration of the vehicle very simply because if such "options" actually existed Toyota would have already implemented them on the assembly line. That is who wouldn't want better acceleration? Toyota selected and tuned...