Single Bed, Three Way Catalyst in the European Environment

The performance of a vehicle equipped with a single bed three way catalyst has been monitored during a 50,000 mile durability test at maximum speed (168 ktnph). Subsequently, emissions as a function of average speed were studied in baseline, durability catalyst and dynamometer aged catalyst conditions.

Principal conclusions are that (i) even after continual exposure to high temperatures (up to 1000°C) for 50,000 miles, the catalyst retains sufficient activity to allow this vehicle to achieve California (1983) and new European (1991) standards; (ii) emissions from the vehicle are substantially reduced by both catalysts over the full speed range (19 - 168 kmph) but are dependent upon the degree of control exerted by the fuel management system and extent of catalyst deactivation; (iii) emissions as determined by the ECER15 test for this vehicle are not representative of those measured over the full performance range, major relative increases occuring at the higher speed ranges (>150 kmph).