WLTP: what it is and how it works

Over the last few years, the automotive world has had to deal with several new rules, among which the one relating to the WLTP cycle stands out . This is a homologation process that entered into force from 1 September 2018 and relates strictly to fuel emissions. Discover with us everything about this system, with the obligation of having to respect it for every car manufacturer of the latest generation.

What is the WLTP cycle

In principle, the WLTP cycle corresponds to the natural evolution of the previous NEDC standard , according to which each car was subjected to a set of tests attesting to its actual consumption. Going into the details, WLTP is the acronym of Worldwide (harmonized) light (vehicles) test procedure, that is a test procedure also intended for light vehicles and approved worldwide.

A test of this type was introduced in order to analyze the consumption of each car in a highly precise manner, with a careful eye on carbon dioxide emissions. These objectives are achieved thanks to the execution of the RDE , ie real road tests that verify the emissions of each car in circumstances similar to reality. In this way, you can choose to buy a model that respects certain standards in terms of pollution, with the prospect of receiving financial benefits on their full maintenance.

How to obtain WLTP approval

As we told you in the previous paragraphs, to obtain the much sought-after WLTP approval it is necessary that the vehicle in question passes a series of very specific tests. Let’s take a look together at the various fundamental steps of a rather elaborate procedure, capable of verifying whether a car fully complies with standards dictated at European level.

  • First, we remind you of the characteristics of the test cycle, which serves to keep the full functionality of your vehicle under control in everyday conditions.
  • The WLTP cyclehas a duration of 30 minutes and its overall distance is 23.25 kilometers, with significant increases compared to the previous NEDCs.
  • The driving phases ofthe test change, with 52% of the time dedicated to driving on urban roads and the remaining 48% on extra-urban ones.
  • The presence of various optionsis another factor taken into utmost consideration.
  • The average speedhas been raised to 46.5 kilometers per hour, while the maximum can reach 131.
  • Tests are performed at a temperatureof 23 degrees, with emissions readings corrected to 14 degrees.
  • Maximum attention is also given to gear changes, which occur more frequently than in the past.

As you can well see, car manufacturers therefore have to deal with much more specific and elaborate tests than previous ones. If the WLTP cycle is not fully respected, the risk is that of not being able to register the vehicle being tested. Consequently, you can easily understand how a series of tests of this type are capable of having a high relevance from all points of view.

What problems can the WLTP cycle hide

The WLTP cycle manages to keep the perfect mechanical efficiency of your vehicle under control. On the other hand, one of the main objectives of such a test has always been to encourage car manufacturers to reduce carbon dioxide emissions in the surrounding atmosphere. However, in some cases, the achievement of such a homologation could coincide with an increase in car consumption , with the various companies forced to carry out a series of efforts to meet the established deadlines.

According to the European Commission, consumption should remain almost identical, although manufacturers may tend to report higher figures following the greater severity of the new WLTP controls . In any case, such a cycle can hide a series of critical issues that could concern not only the car manufacturers, but also those who are about to drive the cars they have selected.

As we have already told you before, the new WLTP tests are much longer and more complex when compared to the previous NEDC standards. In fact, the road tests take into account every single detail of each car, including the options that can increase their weight and alter their aerodynamic system. These parameters could have a significant impact on fuel consumption and emissions, even changing the attitudes of each car under certain road conditions.

As a result, the homologation of a car by each brand has become a much more laborious procedure, with several manufacturers being forced to suspend and resume production based on sudden changes. The situation worsens further in the event of possible delays, with companies unable to sit still for a moment to prevent their high-ranking models from being seriously jeopardized by problems encountered during the WLTP cycle .


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