The New European Driving Cycle test should provide more accurate emission data.
The way emissions are tested in new cars has changed. The current Europe-wide NEDC (New European Driving Cycle) test is being replaced by the WLTP (The Worldwide Harmonized Light Vehicles Test). Introduced in the 1980s, NEDC is based on theoretical driving rather than real driving data. WLTP resolves this by measuring C02 emissions, pollutants and fuel consumption. Manufacturers will have to publish WLTP statistics for any new models introduced from September 2017- models in production before this will not be affected until September 2018. Every car manufacturer will need to get every model certified under the WLTP protocol before September 2018, or it will be illegal to sell the car under EU law.
What is the new test?
The WLTP test will measure a range of factors, including fuel consumption, carbon dioxide (CO2) emissions, nitrogen oxides (NOX), carbon monoxide (CO) and particulates by mass and number (PM and PN). At 30 minutes, WLTP will take 10 minutes longer than the current NEDC method, divided into four parts, two drive cycles, urban and extra-urban cycle. The cycles will measure different speeds, stops, acceleration and braking phases. They also look at powertrains, weights and aerodynamics. Unlike the current NEDC test, WLTP will consider options such as larger wheels or any items that increase the standard kerb weight. Common standard equipment such as heated seats, air conditioning, four-wheel drive and heated windows will also be taken into account.
This all means that the length of the test cycle has increased from 6.84 miles to 14.6 miles, the average speed increases from 75mph to 81.4mph and the time the vehicle spends at standstill is now only 13% compared with 25%.
There is currently no WLTP test available for plug-in hybrid vehicles. Those models will continue to be tested against the NEDC standard until a new test has been formulated and approved.
Benefits of WLTP include:
Real Driving Emissions Test
The RDE (real driving emissions test) has been introduced at the same time as the new WLTP test. It has been created to complement WLTP by confirming test results in real life. This is the first test of its type in the world and will be solely conducted on public roads aimed at exposing the vehicle to a range of different conditions.
Conditions of the test include:
- Low and high altitudes
- Year-round temperatures
- Additional vehicle payload
- Up-hill and down-hill driving
- Urban roads (low speed)
- Rural roads (medium speed)
- Motorways (high speed)
The new RDE test is going to be the toughest challenge for manufacturers developing cars moving forward and major investment will be required in developing new vehicles, and updating testing facilities.
The new WLTP test will produce a more accurate basis for calculating a car’s fuel consumption and emissions, it must be noted that even though WLTP is more accurate, it will not cover all the variations globally and certainly not individual driving style. Therefore, it has to always be remembered that there will be a difference between emissions measured in lab conditions and the real-world driving conditions.