CVS-Cycle and Average City Trip Emissions in Temperatures Below the FTP-Range

Since the start of the discussions to introduce the current federal U.S. standards in Sweden and Norway for model year 1989, the performance of the catalyst system in cold climate has been the topic among interested parties.

To investigate the capabilities of the currently used concept to lower the exhaust emissions at temperatures below the CVS-range (+ 2 < 30°C) tests were performed to start with at 0°C.

Measurements are performed both on non-catalyst and catalyst equipped vehicles of M88 and M89 specifications for comparison. For a short average city trip of 6 km, the HC is reduced by 49 % and CO by 27 % for the M89 calibration compared to the M88 when started and driven in 0°C ambient temperature. The corresponding reduction for NOx is 7 % and the fuel consumption 2 %. A non weighted CVS test equal to 17 km drive, will result in about half of the reductions mentioned above the when tested under the same conditions.