This International Standard specifies the test method for passenger car (term 3.1.1 in ISO 3833:1977) windscreen wiping systems, when they are fitted. It does not specify reference areas or levels of performance. The tests need not be repeated on types of power-driven vehicles which do not differ from one another in respect of the following essential features as far as windscreen wiping performance is concerned: a) shape, size, surface characteristics and aerodynamic characteristics of the windscreen and its surroundings; b) characteristics of each system designated by the vehicle manufacturer as contributing to wiping of the windscreen. This International Standard permits aerodynamic tests to be carried out either in a wind tunnel or on a test track, the results from which are equivalent.