Exhaust emissions from medium- and high-mileage in-service cars with three- way catalytic emissions control system driven under Nordic driving conditions 2000-05-0295
Exhasut emissions were determined from a fleet of some 50 cars
that have been in normal private ownership service in Finnish
driving conditions. These represent typical Nordic climate with
strongly varying ambient temperatures between summer and winter
months. All cars were petrol-fuelled, and had an up-to-date
emissions control system based on a three-way catalytic converter.
Tested vehicles represented model years 1990 to 1996. They had
odometer ratings at the time of testing ranging from a low of
10,000 km up to a high of 373,000 km. The emissions performance was
assessed using U.S. FTP75 urban during schedule. Testing was
carried out at normal ambient temperatures (+22...23° ...).
The paper reports an assessment of typical emissions performance
as a function of distance driven encountered from normal TWC cars
that have been in day-to-day use under sometimes quite rigorous
driving conditions. Additionally, for a subset of vehicles a
follow-up and re-testing was performed after some two years rate
also the stability of the subsequent emissions performance.
The results present information on the actual emission rates of
typical in- service passenger cars. The results can be used, e.g.,
in the emission inventory calculations or to rate the durability of
the TWC emission control system under cold climate conditions.