NEDC is the New European Driving Cycle for measuring fuel consumption.
What Is An NEDC fuel consumption figure?
NEDC is short for 'New European Driving Cycle'. However, despite being called 'New', the NEDC was originally proposed over 30 years ago and introduced in 1990.
The NEDC hasn't been updated since 1997.
When it was introduced, the purpose of the NEDC was to standardise the testing and measurement of fuel consumption by replicating how a car might be driven in European cities.
What Does NEDC measure?
The NEDC measures the fuel consumption of cars over different types of driving conditions (urban driving, driving outside towns and a combined figure from the urban and extra urban figures), plus engine CO2 output during the cycles. However, the tests are conducted in laboratories rather than on real roads and, as such, have fallen into disrepute in recent years.
The Urban Driving Cycle is designed to reflect driving conditions in busy European cities; it assumes low engine load, low exhaust gas temperature, and a maximum speed of 50 km/h. The car engine is started, paused, then accelerated slowly to 15 km/h followed by braking, then the car is stopped.
The cycle is repeated with different variations in speed, acceleration, deceleration and pauses over 195 seconds or a theoretical distance of just under 1 kilometre and is repeated four times.
Extra Urban Cycle
In the Extra Urban Cycle the car undergoes higher speed driving with acceleration, deceleration and cruising over various time periods and speeds over a theortical distance of nearly 7 kilometres.
The Combined Cycle is calculated mathematically from the results of the urban and extra urban cycles and is meant to give an indication of a mixture of driving conditions inside and outside cities.
The NEDC was criticised for being unrepresentative of actual fuel consumption and exhaust emissions under 'real world' conditions. As a result the NEDC has been replace by the World Harmonised Light Vehicle Test Procedure (WLTP) with effect for all new cars sold in the UK from September 2019.
From 1 April 2020 the UK will switch to using the WLTP test results for CO2 output to determine the tax disc or vehicle excise duty for new cars along with the annual company car benefit.
More information about the WLTP system can be found at the website of the UK Vehicle Certification Agency.