Comparisons of the Exhaust Emissions for Different Generations of SI Cars under Real World Urban Driving Conditions

EURO 1, 2 3 and 4 SI (Spark Ignition) Ford Mondeo passenger cars were compared for their real world cold start emissions using an on-board FTIR (Fourier Transform Infrared) exhaust emission measurement system. The FTIR system can measure up to 65 species including both regulated and non-regulated exhaust pollutants at a rate of 0.5 Hz. The driving parameters such as speed, fuel consumption and air/fuel ratio were logged. The coolant water, lube oil and exhaust temperatures were also recorded. A typical urban driving cycle including a loop and a section of straight road was used for the comparison test as it was similar to the legislative ECE15 urban driving cycle. Exhaust emissions were calculated for the whole journey average and compared to EU legislation. The cold start transient emissions were also investigated as a separate parameter and this was where there was the greatest difference between the four vehicles.