The New European Driving Cycle (NEDC) is a version of the former ECE+EUDC test. The ECE+EUDC cycle (also known as the MVEG-A cycle) was used for emission certification of light duty vehicles in Europe (EEC Directive 90/C81/01). The test is performed on a chassis dynamometer. The entire cycle includes four ECE segments, repeated without interruption, followed by one EUDC segment. Before the test, the vehicle is allowed to soak for at least 6 hours at a test temperature of 20-30°C. It is then started and allowed to idle for 40s.
Effective year 2000, that idling period has been eliminated, i.e., engine starts at 0 s and the emission sampling begins at the same time. This modified cold-start procedure is referred to as the New European Driving Cycle (NEDC).
Emissions during the NEDC cycle are sampled according the the Constant Volume Sampling technique, analyzed, and expressed in g/km for each pollutant.
The ECE cycle (shown below) is an urban driving cycle, also known as UDC. It was devised to represent city driving conditions, e.g. in Paris or Rome. It is characterized by low vehicle speed, low engine load, and low exhaust gas temperature.
The EUDC (Extra Urban Driving Cycle) segment has been added after the fourth ECE cycle to account for more aggressive, high speed driving modes. The maximum speed of the EUDC cycle is 120 km/h. An alternative EUDC cycle for low-powered vehicles has been also defined with a maximum speed limited to 90 km/h.
The following table includes a summary of selected parameters for the ECE, EUDC and NEDC cycles.
|Average Speed||km/h||18.7 (with idling)||62.6||33.6|
Related Test Cycles
The ECE urban driving cycle represents Type I test, as defined by the original ECE 15 emissions procedure. Type II test is a warmed-up idle tailpipe CO test conducted immediately after the fourth cycle of the Type I test. Type III test is a two-mode (idle and 50 km/h) chassis dynamometer procedure for crankcase emission determination.