Cupertino, CA Noise Ordinances: Vehicle Noise (2026)
Key Facts
- Governing provision
- Muni Code § 10.48.056
- State standard incorporated
- Veh. Code §§ 27150, 27151
- Test evidence
- CHP Stationary Vehicle Test Procedure
- Off-road vehicles
- separate rule at § 10.48.057
Summary
It is a violation to own or operate a registered vehicle with a faulty, modified or missing exhaust or muffler that produces excessive noise, under Municipal Code § 10.48.056, which incorporates California Vehicle Code muffler standards.
It is a violation of this chapter to own or operate a motor vehicle, including automobiles, trucks, motorcycles and other similar devices of a type subject to registration, as defined in California Vehicle Code, which has a faulty, defective, deteriorated, modified, replaced, or no exhaust and/or muffler system, and which produces an excessive and disturbing noise level, as defined in California Vehicle Code Sections 27150 and 27151. The Stationary Vehicle Test Procedure, as adopted by the California Highway Patrol, may be utilized as prima facie evidence of violation of this section.
Full Breakdown
056 makes it a violation of the noise chapter to own or operate a motor vehicle, including automobiles, trucks and motorcycles subject to registration, that has a faulty, defective, deteriorated, modified, replaced, or missing exhaust and/or muffler system producing an excessive and disturbing noise level, as defined in California Vehicle Code §§ 27150 and 27151. The city can rely on the Stationary Vehicle Test Procedure adopted by the California Highway Patrol as prima facie evidence of a violation, meaning officers do not need a separate local test protocol to cite a driver.
057, covers off-road recreational vehicles such as dirt bikes and dune buggies, applying different numeric caps of 98 dBA within 20 inches of a component at 2,000 to 4,000 RPM stationary, or 80 dBA under acceleration at 50 feet, and cites California Vehicle Code § 38365 rather than §§ 27150-27151. 040, but each targets the vehicle's exhaust/muffler condition rather than ambient sound at a receiving property.
Violations & Fines
A violation of § 10.48.056 is a misdemeanor under § 10.48.070, punishable per Chapter 1.12 by a fine up to $1,000, up to six months in jail, or both; the City Attorney may instead charge it as an infraction with fines of $100, $200 and $500 for repeat violations within a year.
Frequently Asked Questions
Is a loud aftermarket exhaust illegal in Cupertino?
How does Cupertino prove a muffler violation?
Do dirt bikes and off-road vehicles face the same muffler rule?
Sources & Official References
Other rules in Cupertino
California rules heatmap·Compare Cupertino to another location·View the California noise ordinances overview
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How other cities in Santa Clara County handle vehicle noise.