Statistical analysis of catalyst data

Abstract

SUMMARYCatalytic converters are crucial for the reduction of car emissions. The performance of aging catalysts in use has not been well known. Data on catalysts from scrapped cars of different ages has been taken in well controlled laboratory conditions. The statistical analysis of these data compares and uses different models of the regression type and also generalized regression for ordered categorical data. A significant, though not very dramatic, deterioration with age is shown for the catalytic converters. The overall impression is, however, that converters like those examined in this study do function reasonably well at least up to about 200000 km driving distances.