Rancho Cucamonga, CA Noise Ordinances: Vehicle Noise (2026)

Section 17.66.050(G) sets commercial and office noise provisions inside Chapter 17.66, Performance Standards. Subsection G.3, 'Vehicle repairs and testing,' prohibits repairing, rebuilding, modifying, or testing any motor vehicle, motorcycle, or motorboat in a manner that increases a noise disturbance between 10:00 p.m. and 8:00 a.m. when the activity is adjacent to a residential area. It sits beside G.1, which caps general commercial exterior noise at 65 dBA overnight (10 p.m. to 7 a.m.) and 70 dBA during the day, and G.2, which bars loud loading and unloading between 10 p.m. and 7 a.m. near homes.

Together these standards mean an auto repair shop, tire center, or home-garage mechanic working next to a residential lot cannot run engines, use pneumatic tools, or test exhaust systems loud enough to disturb neighbors during the 10 p.m. to 8 a.m. window, an hour later than the general commercial curfew because vehicle work tends to be noisier. Measurement follows Section 17.66.030: from a nonresidential parcel adjacent to a residential zone, the city measures at the residential property line. The rule applies citywide regardless of zoning, covering licensed repair shops in Industrial and General Commercial zones as well as a resident revving an engine or testing a modified exhaust in a driveway beside a neighbor's home. Code enforcement responds to noise complaints from adjacent residents and can inspect the site and cite the responsible business or property owner.