Cancels and replaces the first edition (1981). Specifies an engineering method for measuring the noise emitted by accelerating road vehicles. The specifications are intended to reproduce the noise levels in urban traffic flow of irregular character which requires the use of intermediate gears with full utilization of the engine power available. The test method calls for an acoustical environment which can only be obtained in an extensive open space. Such conditions can usually be provided for: type approval measurements of vehicles; measurements at the manufacturing stage and at official testing stations.