Development of an indicator for the emission control of diesel passenger cars

An indicator for the CO and HC emission control, based on the instant values of exhaust temperature and engine-out emissions of CO and HC, is developed in the case of Euro4 diesel engines. For a certain level of tail-pipe emissions and for a given diesel oxidation catalyst, this indicator can estimate the necessary catalytic volume to satisfy the regulation limits. More than this, it can also indicate the parts of NEDC that mainly contribute to this catalytic volume because of their low temperature or high engine-out CO or HC emissions or a combination of both of them. This indicator can help engine-developing engineers to find out how they can to minimize the total catalytic volume, by controlling HC and CO engine-out emissions and exhaust temperature at certain parts of NEDC. This indicator can also be used to minimize the number of necessary tests during engine development by directly comparing two engine tunings from the point of view of CO and HC emission control and thus estimate the necessary catalytic volume for each tuning.