Methodology and results of the evaluation of alternative short tests applied in inspection and maintenance programmes

The aim of this paper is to present a methodology for the evaluation of the effectiveness of alternative short tests that could be applied in an inspection and maintenance programme. The basis for the evaluation, apart from the environmental benefits, is the social and political acceptance that constitutes crucial parameters in the implementation of a short test. The methodology has been applied to a large sample of three way catalyst equipped vehicles representative of the European fleet and the effectiveness of 10 alternative short tests has been evaluated. The short tests include transient and steady state (both loaded and unloaded) procedures, as well as the idle test of the current European legislation. The steady state tests find it difficult to identify high emitters, approximately 15% are detected, and as a result the predicted potential for environmental benefit is less than 5% for all pollutants. The transient tests, on the other hand, seem to be able to identify approximately 70% of gross emitters and therefore the emission reduction potential is predicted to be as high as 20% for all pollutants.