Singapore legislation
Regulation 33
of Road Traffic (Motor Vehicles, Construction and Use) Rules
Regulation 33
Silencer
Subregulation 1
Every vehicle propelled by an internal combustion engine shall be fitted with a silencer, expansion chamber or other contrivance suitable and sufficient for reducing as far as may be reasonable the noise caused by the escape of the exhaust gases from the engine.
Subregulation 2
With effect from 1st July 1981, the exhaust pipe of every vehicle shall end in a straight section of at least 100 millimetres in length and the outlet of the exhaust pipe shall be on the off-side or at the rear of the vehicle.