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Worldwide Harmonized Light Vehicle Test Procedure (WLTP)

  • For a clearer picture of vehicle emissions and consumption

The testing measures for car pollutants, emissions and fuel consumption are changing. That’s because the old system, the so-called New European Driving Cycle (NEDC) introduced in the 1980s, has become outdated. It will gradually be replaced by the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). Whereas the NEDC was based on theoretical driving, the new laboratory test is designed to give a more accurate picture of fuel consumption, pollutants and CO2 emissions in passenger cars.

The WLTP is supplemented by an emission test that measures pollutants directly on the road, the RDE (Real Driving Emissions). As the name suggests, it measures emissions in the real-world, not in the laboratory. These improved measures are gradually rolled out across the European Union and other regions worldwide. From September 2018, all new cars must be certified according to the WLTP standard.

What’s the difference between NEDC and WLTP?

  • The new WLTP test aims to provide more accurate comparable vehicle data that better reflects realistic driving conditions. For example, while the old NEDC standard only covered three driving scenarios (urban, extra-urban, combined) - the WLTP driving cycle is divided into four parts with different average speeds: low, medium, high and extra high. Each part contains a variety of driving phases, stops, acceleration and braking phases. For a certain car type, each powertrain configuration is tested with WLTP for the car’s lightest (most economical) and heaviest (least economical) version. It also takes into account the effects of optional equipment on weight and aerodynamics etc.

    As a result, both the test distance and the overall duration of the procedure have been extended. The combination of all these new measures should offer a real-world picture of a car’s performance on the road. Even so, it is important to bear in mind that the test is still based on lab data. WLTP cannot measure individual variables like personal driving style which can also impact fuel consumption and emissions.

Test duration 20 min. 30 min.
Test distance Approx. 11 kilometres Approx. 23 kilometres
Time spent stationary 25% 13%
Test phases Urban, extra-urban, (combined) Low, Medium, High, Extra high, (Combined); (plus “City” for electric vehicles and vehicles with plug-in hybrid drivetrain)
Speed Average: 34 km/h Maximum: 121 km/h Average: 46.6 km/h Maximum: 131 km/h
Start temperature 20-30°C - Cold engine start 14°C – 23°C - Cold engine start
Special equipment options Not taken into consideration. CO2 values will now take into account the weight and effects on aerodynamics of optional equipment such as tyres, air conditioning etc.

WLTP benefits at a glance

    • More realistic driving behaviour
      A greater range of driving situations (urban, suburban, main road, motorway)
      Longer test distances
      More realistic ambient temperatures
      Higher average and maximum speeds
      Higher average and maximum drive power
      More dynamic and representative accelerations and decelerations
      Shorter stops
      Optional equipment: CO2 values and fuel consumption are provided for individual vehicles as built
      Stricter car set-up and measurement conditions
      Allows best and worst-case values to reflect the options available for similar car models

If you purchased a Kia in 2017 showing the old NEDC system, you may find that the same car released later with the new WLTP states higher levels of CO2. This is due to the stricter and more thorough nature of the new testing system. However, to avoid confusion, cars released during the interim period will still be sold showing the back-translated NEDC figures to make data more comparable. Another point to note, the tests will not affect actual fuel consumption, but they may show higher CO2 values due to the stricter measuring.

More CO2 shouldn’t equate to more tax during the interim period. It is up to the national governments to create fair regulations to ensure there is no additional financial burden when purchasing a more recent model of the same car.

Conventional petrol and diesel engines will be measured using the procedures outlined above. However, plug-in hybrid vehicles will undergo more tests to account for different charging states. For example, one test will measure performance with a full battery; the cycle will then be repeated until the battery is empty; a final test will measure data using the power derived exclusively from the combustion engine and regenerative braking. The combined figures will then form the basis for CO2 emission levels.

WLTP transition timeline

  • since September
    New models are tested according to WLTP. During this interim period, data is back-translated into NEDC values to allow for better comparison with older models.
  • September
    All cars sold in the EU must be certified with WLTP. An exception will be made for end-of-series vehicles to allow for a limited number of unsold vehicles in stock that were approved under the old NEDC test to be sold for one more year.
  • January
    All car dealerships will show test values only according to WLTP on all their new models.
  • December
    All countries that adopt the EU legislation for vehicle registration will have to supply WLTP values for all vehicles.

Kia Guide to greener driving

  • EcoDynamics - Intelligent Thinking

    Our fuel stretching EcoDynamics technology helps save up to 12% more fuel and reduce your carbon footprint - It cuts off the engine whenever the car is stationary, and gets you going again, simply by pressing the clutch.

  • Gearshift indicator

    The gearshift indicator advises you when to change gear, thus saving fuel, reducing emissions and reducing wear and tear.

  • Less is more

    Minimise the use of air-conditioning, demister etc. – just like everyday household items, these consume power which affects fuel consumption.

  • Smart stopping

    Avoid engine idling. If you’re stationary for more than 40 seconds, turn the engine off to save fuel.

  • Tyres

    Stay pumped up: Regularly check your tyres. Underinflated tyres waste fuel and affect handling, and increase wear.

  • Recycling your car

    One of our goals is to dispose environmentally friendly cars in an equally environmentally friendly way. That’s why we use Design for Recycling (DfR) guidelines and offer an 'End-of-life' recycling scheme.