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Noise Concerns

Jacobs Vehicle Systems® has received inquiries regarding engine brake use and noise. The posting of engine brake signs along the roads and highways of North America has created much controversy with both residents and drivers alike. This page has been established to inform interested parties about engine exhaust noise, and provide the data and information necessary to understand the issue. We hope you find the information on this page useful, and we welcome any feedback. Complete our feedback form.

More Information on Engine Exhaust Noise

Questions & Answers

I've seen signs posted that say "No Jake Brakes", what does this mean?

Jake Brake is a registered trademark of Jacobs Vehicle Systems. The term "Jake Brake" is sometimes incorrectly used to refer to compression release type engine brakes in general. The term correctly refers to all of Jacobs Vehicle Systems retarding products. When an engine brake is used on a vehicle with a poorly muffled or un-muffled engine exhaust (using straight pipes for example), the sound can be offensive, which is what prompted the sign you saw. The sign you saw might have unfairly used our trademark, making it brand specific.

I'm bothered by the noise of big trucks using their Engine Brakes, what can I do?

The federal government has required all vehicles manufactured since 1978 to meet noise requirements when delivered to the customer, so trucks have been required to meet the requirements when they leave the dealership as new vehicles for quite some time. The real problem here is modified or defective exhaust systems. The use of the engine brake is not the problem. Citizens and truck drivers can both do their part to keep the noise down. Citizens, encourage your local police to stop noisy vehicles and check them for muffler integrity. Truckers, if you know someone who is operating a vehicle with an excessively loud exhaust system, encourage him or her to fix it.


Noise Information & Ordinance Help

To better understand engine exhaust noise and Jacobs' standpoint, view our updated engine brake noise brochure or white paper.

If you are made aware of an upcoming legislative ordinance, or it is your understanding that your community is considering an ordinance that prohibits Jake Brake or engine brake use, please let us know by using our feedback form.



Noise Laws & Links

Noise Laws by State Quick Reference
We have compiled US noise control laws by state including decibel limits and fines for ordinance violations for quick reference.    
Washington State
Montana Legislation
Montana's 2003 House Bill No. 237 correctly recognizes engine exhaust noise issue by requiring motor vehicles equipped with an engine compression brake device to have a muffler in good working condition.
Multi-State Highway Transportation Agreement (MHTA) Update.
Model legislation based on the recent law in Colorado requiring commercial vehicles with engine brakes to have proper exhaust mufflers on any truck operating in the state. The MHTA has adopted Colorado's law (with some modification) and it has been brought back to the member states of Arizona, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.

American Association of Motor Vehicle Administrator (AAMVA)
This web site contains information on the muffler identity and inspection procedures that can be adopted in your state. With these criteria, a commercial vehicle can be inspected for the presence and integrity of an appropriate muffler system.


In the News

City Investigates Noise Concerns, Policing of Illegal Exhaust Systems Needed 

BAD AXE It doesn’t appear city council is going to pass an ordinance any time soon to ban compression release engine brakes often called “Jake brakes,” a term that comes from a Jacobs Engine brake.


During a public hearing Monday, council heard from three residents one who was very much in favor of the ban, another who was very much opposed, and a third who felt the ordinance’s language was flawed.

Read Online


Typical Heavy Duty Vehicle Noise Test

Image of Typical Heavy Duty Vehicle Noise Test

Engine Brake Noise Test

noiseleft.gif noiseright.gif


Grille to Grille - Jake Brake on DD15

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