Minnehaha County, SD Noise Ordinances: Vehicle Noise (2026)

South Dakota's statewide muffler statute (SDCL 32-15-8) reads: 'Every motor vehicle shall be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise... and no person shall use a muffler cut-out, bypass, or similar device upon a motor vehicle on a highway.' SDCL 32-15-9 prohibits modifications that amplify exhaust noise above the level produced by the manufacturer's original equipment. Violation is a Class 2 misdemeanor under SDCL 32-15-12 (up to 30 days jail and a $500 fine, plus court costs). Engine-braking ('Jake brake') restrictions are enforced as signed by the South Dakota Department of Transportation on state highways and by the Minnehaha County Highway Department on county routes; common signed-restriction corridors include city approaches into Sioux Falls and Brandon. Loud aftermarket exhaust on motorcycles is also reachable under SDCL 32-15-8/-9. SDCL 22-18-35 (disorderly conduct — 'unreasonable loud noise') supplies a backstop for repeated cruising and stationary revving outside the moving-traffic context. Inside Sioux Falls, Sioux Falls Code Title 39 (Vehicles and Traffic) layers additional city-only restrictions; those do not extend to unincorporated county roads. South Dakota does not have a statewide motor-vehicle window-tint noise rule analogous to California Vehicle Code 27150-27151, but the muffler statute substantively reaches the same conduct.