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CO, CO2, HC, CH4, NOx, N2O emissions as well as emissions of 10 PAHs and fuel consumption were measured on 10 conventional petrol-engined passenger cars, 10 vehicles equipped with 3-way catalysts, and 5 diesel-engined vehicles over a great number of driving cycles under hot or cold start conditions: the 2 standardized European and American cycles, Highway cycle, 4 hot cycles representative of real-world driving conditions, and 3 representative mini-cycles, which have been repeated 15 times after a cold start. Simultaneously, water and oil temperatures were measured to assess engine temperatures. The analysis of the results enabled the monitoring of emission and temperature changes with time for various kinematic types. The limit of hot temperature, the distance travelled under cold start conditions (over about 6 km), the excess emission rates under cold start conditions, and absolute excess emissions after a cold start could be thus determined.

Exhaust concentration (in ppm) and emission (in g/km) measurements (for CO, HC, NOx and CO2) will be compared over a sample of 49 as-received gasoline engined vehicles, in which 10 were equipped with a 3-way catalyst, in order to assess the viability of rapid methods of emission measurements. The exhaust gas concentrations at the tailpipe were measured from 15 engine operating conditions (6 engine speeds, 4 gear choice). The emission measurements were performed using European standardized cycles ECE15 and ECE15+EUDC and 4 specific actual cycles, representative of the various vehicle usages. The results obtained are not encouraging as regards the interest of concentration measurements at the tailpipe, even with optimum engine operating conditions: the relationship between exhaust concentrations and actual or standardized emissions is always very poor. The best correlation depends on the pollutant, but could be for 3000 rpm in neutral.