What is WLTP?

Last updated November 30, 2021

WLTP stands for Worldwide Harmonised Light Vehicle Test Procedure. This has been the lab test used to check how cars perform in everyday driving conditions since September 2018.

This test applies to all new cars manufactured and brought to market since September 2017. The WLTP testing is carried out by independent testers on vehicles the manufacturer has provided them before the car is placed in showrooms.

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What process was used before 2018?

The test that was used before 2018 was NEDC, which is an acronym for New European Driving Cycle. This test was carried out to test and assess passenger vehicle emissions and fuel economy. However, the NEDC was often scrutinized for providing figures that were not attainable in the real world under varied driving conditions.

Therefore, the WLTP was completely redesigned to include both lab testing and real-world testing. Unlike NEDC testing, WLTP will also include results for all optional equipment that may affect the figures such as bigger wheels or a sunroof.

What does the test consist of?

Like the old NEDC test, The WLTP tests are carried out in a lab on a rolling road. However, the difference between the tests is the conditions. The WLTP is 30 minutes whereas the NEDC is just 20 minutes. The temperature of the WLTP test is set at 23 degrees, to reflect real world conditions. The length of the test and temperature alongside the five driving cycles are set to reflect modern-day driving conditions.

Part of the WLTP procedure is the Real Driving Emissions, this test is between 1.5 to 2 hours and is carried over 50 miles. The route will cover an equal split of urban, rural and motorway routes to ensure all possible conditions are covered. This is a validation exercise for the WLTP results.

How does the WLTP affect me?

The WLTP will aid you in making a more informed decision when choosing to purchase your next car. The results of the WLTP may be a deciding factor, where a car may cost slightly more upfront but will save you on the cost of fuel in the long run you might choose this over the slightly cheaper model.

CO2 emissions are also tested as part of the WLTP, which will determine how much VED or road tax your vehicle is subject to. Therefore, this may influence your final decision when selecting a new car as certain models will be in lower tax bands than others, which will save you money in the long term on yearly tax costs.

How are hybrid and electric vehicles tested?

Due to the nature of the vehicle, plug-in hybrids will need to do the test several times under different conditions. The test will start when the car has a fully charged battery and the test will continue until the battery has gone completely flat. This gives a more accurate representation of the economy that plug-in hybrids can expect. These numbers will then be collated and calculated to work out the official emissions and economy figures depending on the car’s electric range. If you are interested in purchasing an electric vehicle, we have a list of the longest range electric cars with their WLTP figures here.

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