New European Driving Cycle
The NEDC, previously known as the MVEG-A cycle, is an emission certification test used for light duty vehicles in Europe. It is performed on a chassis dynamometer and consists of four ECE segments, followed by one EUDC segment. The ECE cycle is an urban driving cycle designed to represent city driving conditions with low vehicle speed, low engine load, and low exhaust gas temperature.
The EUDC segment is added after the fourth ECE cycle to account for more aggressive high-speed driving. 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., after which the modified cold-start procedure begins with the engine starting at 0 seconds and the emission sampling starting at the same time. Emissions during the NEDC cycle are sampled using the Constant Volume Sampling technique and expressed in g/km for each pollutant. A low-powered vehicle alternative EUDC cycle has also been defined with a maximum speed of 90 km/h.