This International Standard specifies an engineering method for measuring the noise emitted by accelerating road vehicles.

The method is designed to meet the requirements of simplicity as far as they are consistent with reproducibility of results under the operating conditions of the vehicle.

The specifications are intended to reproduce the noise levels which are produced during the use of intermediate gears with full utilization of the engine power available as may occur in urban traffic.

The test method requires an acoustical environment which can only be obtained in an extensive open space. Such conditions can usually be provided for:

• type approval measurements of vehicle;
• measurements at the manufacturing stage; and
• measurements at official testing stations.